System and method for testing a suction valve

Abstract

System and method for testing a suction valve (200). The suction valve (200) is placed in a test chamber (301) of a test unit (300). The suction valve has a suction valve body (201) surrounding a suction valve piston chamber (202) with a suction valve inlet opening (203) at the top and a suction valve outlet opening (204) at the bottom. The test unit (300) holds a test oil inlet (302a) connected to the suction valve outlet opening (204) and a test oil outlet (303a) connected to the suction valve inlet opening (203). The suction valve (200) is in closed position, while test oil is supplied to the test oil inlet (302a) at a first test oil pressure being above a fuel oil opening pressure for which the suction valve (200) starts opening. If test oil reaches out through the test oil outlet (303a) there is a leak.

Description

[0001] TITLE

[0002] SYSTEM AND METHOD FOR TESTING A SUCTION VALVE

[0003] TECHNICAL FIELD

[0004] The disclosure relates to a system and method for testing a suction valve, which may be used for supply of a liquid gas, such as Ammonia or Methanol, to a Fuel Booster Injector Valve for a two-stroke combustion engine

[0005] BACKGROUND

[0006] CN 111811768 A discloses a system for testing a valve. The valve may be used in large hydroelectric power stations, and the valve may be a 2-3 meters ball valve, where water leakage can have a significant effect on operation. For testing, the valve is placed in a test chamber (202) of a test unit. The test unit holds a test inlet (201) for supplying a liquid at a test pressure, and the test unit further holds a test outlet (102) for checking if any test liquid reaches out through the test outlet (102).

[0007] A new Fuel Booster Injector Valve for Ammonia or Methanol, FBIV-A / M, for a two-stroke combustion engine has been developed by MAN Energy Solutions. The injector valve is supplied with sealing oil and the liquid gas is supplied via a Safety Suction Valve, SSV, to a piston chamber. High pressure hydraulic oil is acting on top of a piston to increase or boost the pressure of the liquid fuel within the piston chamber to an injection pressure for which the injection valve, FBIV-A / M, opens and fuel is injected.

[0008] Thus, there is a need for testing that the safety-suction valve stays closed without leaks when receiving a high oil pressure corresponding to the boosted or increased pressure of liquid fuel obtained within the piston chamber.

[0009] SUMMARY

[0010] 03786-PCT It is an object of the present disclosure to provide a method and a system for testing a suction valve for valve leaks. The suction valve may be part of an injector valve with fuel being supplied to the injector valve through the suction valve.

[0011] This object is achieved in accordance with a first aspect by providing a method of testing a suction valve for an injector valve, wherein the suction valve is placed in a test chamber of a test unit, and wherein the suction valve has: a suction valve body surrounding a suction valve piston chamber with a suction valve inlet opening at the top and a suction valve outlet opening at the bottom, which suction valve piston chamber holds a suction valve spring and a suction valve piston, said suction valve piston having a piston valve seat formed at an upper end of the suction valve piston, said suction valve piston chamber holding a suction valve connection formed at an upper end of the suction valve piston chamber for receiving the piston valve seat when the suction valve is in closed position, and said suction valve piston chamber holding a bottom recess formed at a lower end of the suction valve piston chamber for receiving a bottom part of the suction valve piston when the suction valve is in open position; said valve body having one or more upper valve fluid channels providing a fluid connection from the suction valve piston chamber to outer wall parts of an upper part of the suction valve body; and said valve body having one or more lower valve fluid channels providing a fluid connection from the suction valve piston chamber to outer wall parts of a lower part of the suction valve body; wherein, when the suction valve is open, the piston valve seat is positioned below the suction valve connection, thereby providing a fluid connection from the suction valve inlet opening to the outer wall parts of the upper part of the suction valve body via the upper valve fluid channels, and the bottom part of suction valve piston is received at the bottom recess, thereby providing at least a partly closure for a fluid connection from the suction valve outlet opening to the outer wall parts of the lower part of suction valve body via the lower valve fluid channels; wherein, when the suction valve is closed, the piston valve seat is received by the suction valve connection, thereby providing a closure to the fluid connection from the suction valve inlet opening to the outer wall parts of the suction valve body via the upper valve fluid channels, and the bottom part of the suction valve piston is positioned above the bottom recess, thereby providing a fluid connection from the suction valve outlet

[0012] 03786-PCT opening to the outer wall parts of the lower part of suction valve body via the lower valve fluid channels; wherein the test unit holds a test oil inlet being fluidly connected to the suction valve outlet opening via a test oil inlet channel, said test unit further holding a test oil outlet being fluidly connected to the suction valve inlet opening via a test oil outlet channel being formed between an upper part of the suction valve body holding the suction valve inlet opening and a test unit lid providing a closure to an upper part of the test chamber; wherein a tight closure is provided between an upper part of the suction valve body and an upper part of the test chamber, said tight closure being provided above the upper valve fluid channels; wherein a test chamber clearance is provided between the outer wall parts of the suction valve body and the wall parts of the test chamber, thereby providing a fluid connection from the lower valve fluid channels via the test chamber clearance to the to the upper valve fluid channels; and wherein said method of testing a suction valve comprises a suction valve leakage test, which comprises: securing that the suction valve placed in the test chamber is in closed position, whereby the suction valve piston seat is received by the suction valve connection due to pressure from the suction valve spring; supplying test oil at a first test oil pressure to the test oil inlet, said first test oil pressure being above a fuel oil opening pressure for which the suction valve is configured to start opening by moving the piston valve seat below the suction valve connection; and checking if any test oil reaches out through the test oil outlet.

[0013] If any test oil is observed reaching out through the test oil outlet, there is a leak in the suction valve.

[0014] It is noted that the test oil supplied at the first test oil pressure at the test oil inlet is further received at the suction valve outlet opening and thereby by the suction valve piston, whereby the suction valve piston is pressed upwards to hold the suction valve in the closed position with the piston valve seat received by the suction valve connection.

[0015] It is preferred that hydraulic oil is used for the supplied test oil.

[0016] 03786-PCT In a possible implementation form of the method of the first aspect, the step of securing that the suction valve placed in the test chamber is in closed condition comprises securing that no outer pressure being above the fuel oil opening pressure is supplied to the suction valve piston.

[0017] In a possible implementation form of the method of the first aspect, the first test oil pressure is substantially higher than the fuel oil opening pressure, such as at least two, three, four or five times the first fuel opening pressure.

[0018] In a possible implementation form of the method of the first aspect, the first test oil pressure is substantially higher than the fuel oil opening pressure, such as at least ten or twenty times the first oil opening pressure.

[0019] In a possible implementation form of the method of the first aspect, the fuel oil opening pressure of the suction valve is in the range of about 2 to 20 bar, such as around 2,5 bar or around 5 bar.

[0020] In a possible implementation form of the method of the first aspect, the first test oil pressure is in the range of 100 to 400 bar, such as about 300 bar.

[0021] The test oil supplied at the test oil inlet runs through the test oil inlet channel into the suction valve outlet opening, through the lower valve fluid channels, through the test chamber clearance, and into the upper valve fluid channels, where the test oil is stopped by the closure provided by the suction valve piston seat being received by the suction valve connection. If there is any leakage, part of the test oil will pass between the suction valve piston seat and the suction valve connection into the suction valve inlet opening, through test oil outlet channel and out via the test oil outlet.

[0022] In a possible implementation form of the method of the first aspect, the test chamber clearance comprises a lower test chamber clearance, a middle test chamber clearance, and an upper test chamber clearance.

[0023] 03786-PCT In a possible implementation form of the method of the first aspect, the middle test chamber clearance holds two opposed clearances, which together partly surrounds the suction valve body.

[0024] In a possible implementation form of the method of the first aspect, the lower test chamber clearance provides a clearance, which fully surrounds the one or more lower valve fluid channels, and the upper test chamber clearance provides a clearance, which fully surrounds the one or more upper valve fluid channels.

[0025] In a possible implementation form of the method of the first aspect, the test unit lid holds a test unit piston positioned for engagement of the suction valve piston when the suction valve is placed in the test chamber of the test unit, and the method of testing the suction valve further comprises a suction valve piston test, said suction valve piston test comprising: providing a movement of the test unit piston to engage with the suction valve piston at a first position, and further providing a pressure on the test unit piston and thereby the suction valve piston to overcome a spring force provided by the suction valve spring, whereby the test unit piston and the suction valve piston are moved a first length from the first position; release the pressure on the test unit piston and thereby the pressure on the suction valve piston; and observing whether the test unit piston returns to the first position.

[0026] In a possible implementation form of the method of the first aspect, the test unit lid holds a test unit piston positioned for engagement of the suction valve piston when the suction valve is placed in the test chamber of the test unit, and a bottom part of the suction valve piston holds a suction valve piston recess and a number of narrow suction valve piston fluid channels, wherein, when the suction valve is open, the bottom part of suction valve piston is received at the bottom recess and a fluid passage is provided from the suction valve outlet opening to the outer wall parts of the lower part of suction valve body via the suction valve piston recess and the suction valve piston channels; and wherein said method of testing the suction valve further comprises a suction valve open test, said suction valve open test comprising:

[0027] 03786-PCT providing a test unit pressure on the test unit piston and thereby the suction valve piston, said test unit pressure being higher than the fuel oil opening pressure to overcome a spring force provided by the suction valve spring, whereby the test unit piston and the suction valve piston holding the piston valve seat are moved into an end position in which the suction valve is fully open; maintaining the test unit pressure on the test unit piston to hold the suction valve piston in the end position; supplying test oil at a second test oil pressure to the test oil inlet, said second test oil pressure being below the difference between the test unit pressure provided to the test unit piston and the fuel oil opening pressure; checking if any test oil reaches out through the test oil outlet; and release the pressure on the test unit piston and the pressure on the suction valve piston, thereby closing the suction valve.

[0028] If any test oil is observed reaching out through the test oil outlet, then the suction valve is open. When releasing the pressure on the test unit piston and thereby the pressure on the suction valve piston, the spring force from the suction valve spring forces the piston valve seat into connection with the suction valve connection, thereby closing the suction valve.

[0029] In a possible implementation form of the method of the first aspect, the suction valve open test may further comprise the step of increasing the pressure of the supplied test oil to a third test oil pressure being substantially higher than the fuel oil opening pressure; and checking if any test oil reaches out through the test oil outlet.

[0030] If any test oil is observed reaching out through the test oil outlet, there is a leak in the suction valve.

[0031] In a possible implementation form of the method of the first aspect, the third test oil pressure is in the range of 100 to 400 bar, such as about 300 bar.

[0032] In a possible implementation form of the method of the first aspect, the suction valve body is placed in the test chamber with a bottom part of the section valve body resting on a bottom part of the test chamber.

[0033] 03786-PCT In a possible implementation form of the method of the first aspect, the suction valve body and the test chamber are configured for providing a tight closure between a lower part of the suction valve body and a lower part of the test chamber.

[0034] In accordance with the first aspect there is also provided a system for testing a suction valve for use by an injector valve, said system comprising a test unit with a test chamber and the suction valve, wherein the suction valve is placed in the test chamber, and wherein the suction valve has: a suction valve body surrounding a suction valve piston chamber with a suction valve inlet opening at the top and a suction valve outlet opening at the bottom, which suction valve piston chamber holds a suction valve spring and a suction valve piston, said suction valve piston having a piston valve seat formed at an upper end of the suction valve piston, said suction valve piston chamber holding a suction valve connection formed at an upper end of the suction valve piston chamber for receiving the piston valve seat when the suction valve is in closed position, and said suction valve piston chamber holding a bottom recess formed at a lower end of the suction valve piston chamber for receiving a bottom part of the suction valve piston when the suction valve is in open position; said valve body having one or more upper valve fluid channels providing a fluid connection from the suction valve piston chamber to outer wall parts of an upper part of the suction valve body; and said valve body having one or more lower valve fluid channels providing a fluid connection from the suction valve piston chamber to outer wall parts of a lower part of the suction valve body; wherein, when the suction valve is open, the piston valve seat is positioned below the suction valve connection, thereby providing a fluid connection from the suction valve inlet opening to the outer wall parts of the upper part of the suction valve body via the upper valve fluid channels, and the bottom part of suction valve piston is received at the bottom recess, thereby providing at least a partly closure for a fluid connection from the suction valve outlet opening to the outer wall parts of the lower part of suction valve body via the lower valve fluid channels; wherein, when the suction valve is closed, the piston valve seat is received by the suction valve connection, thereby providing a closure to the fluid connection from the suction valve inlet opening to the outer wall parts of the suction valve body via the upper valve fluid channels, and the bottom part of suction valve piston is positioned above from

[0035] 03786-PCT the bottom recess, thereby providing a fluid connection from the suction valve outlet opening to the outer wall parts of the lower part of suction valve body via the lower valve fluid channels; wherein the test unit holds a test oil inlet being fluidly connected to the suction valve outlet opening via a test oil inlet channel, said test unit further holding a test oil outlet being fluidly connected to the suction valve inlet opening via a test oil outlet channel being formed between an upper part of the suction valve body holding the suction valve inlet opening and a test unit lid providing a closure to an upper part of the test chamber; wherein a tight closure is provided between an upper part of the suction valve body and an upper part of the test chamber, said tight closure being provided above the upper valve fluid channels; and wherein a test chamber clearance is provided between the outer wall parts of the suction valve body and the wall parts of the test chamber, thereby providing a fluid connection from the lower valve fluid channels via the test chamber clearance to the to the upper valve fluid channels.

[0036] In a possible implementation form of the system of the first aspect, the test chamber clearance comprises a lower test chamber clearance, a middle test chamber clearance, and an upper test chamber clearance.

[0037] In a possible implementation form of the system of the first aspect, the middle test chamber clearance holds two opposed clearances, which together partly surrounds the suction valve body.

[0038] In a possible implementation form of the system of the first aspect, the lower test chamber clearance provides a clearance, which fully surrounds the one or more lower valve fluid channels, and the upper test chamber clearance provides a clearance, which fully surrounds the one or more upper valve fluid channels.

[0039] In a possible implementation form of the system of the first aspect, the test unit lid holds a test unit piston positioned for engagement of the suction valve piston when the suction valve is placed in the test chamber of the test unit.

[0040] 03786-PCT In a possible implementation form of the system of the first aspect, a bottom part of suction valve piston holds a suction valve piston recess and a number of narrow suction valve piston fluid channels, wherein, when the suction valve is open, the bottom part of suction valve piston is received at the bottom recess and a fluid passage is provided from the suction valve outlet opening to the outer wall parts of the lower part of suction valve body via the suction valve piston recess and the suction valve piston channels.

[0041] The foregoing and other objects are achieved by the features of the independent claims. Further implementation forms are apparent from the dependent claims, the description and the figures. These and other aspects of the invention will be apparent from the embodiments described below.

[0042] BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In the following detailed portion of the present disclosure, the aspects, embodiments and implementations will be explained in more detail with reference to the example embodiments shown in the drawings, in which:

[0044] Fig. 1 is a longitudinal sectional view of a fuel booster injector valve holding a suction valve according to an example embodiment;

[0045] Fig. 2 is a longitudinal sectional view of suction valve in closed position for use in the injector valve of Fig. 1 according to an example embodiment;

[0046] Fig. 3 is a longitudinal sectional view of the suction valve of Fig. 2 in open position according to an example embodiment;

[0047] Fig. 4 is a longitudinal sectional view of the injector valve of Fig. 1 , with the sectional view taken at a distant to a centre axis of the valve, according to an example embodiment;

[0048] Fig. 5 is a longitudinal sectional view of a lower part of the injector valve of Fig. 1, with the sectional view taken at a first distance to a centre axis of the injector valve, according to an example embodiment;

[0049] 03786-PCT Fig. 6 is a longitudinal sectional view of a lower part of the injector valve of Fig. 1, with the sectional view taken at a second distance to a centre axis of the injector valve, according to an example embodiment;

[0050] Fig. 7 is a longitudinal sectional view of the injector valve of Fig. 1 , with the sectional view taken at a 90 degree angle relative to the sectional view of Fig. 1 , according to an example embodiment;

[0051] Fig. 8 is an amplified view of a lower part of the sectional view of Fig. 7 according to an example embodiment;

[0052] Fig. 9 is an amplified sectional view of a part of the injector valve of Fig. 1 illustrating the arrangement of the suction valve, according to an example embodiment;

[0053] Fig. 10 is an amplified sectional view of a part of the injector valve of Fig. 1 illustrating the arrangement of the suction valve, with the sectional view taken at a distance to a centre axis of the injector valve, according to an example embodiment;

[0054] Fig. 11a is an amplified sectional view of a part of the injector valve of Fig. 1 illustrating the arrangement of the suction valve, with the sectional view taken at a 90 degree angle relative to the sectional views of Figs. 1 and 9, and at a distance to a centre axis of the injector valve, according to an example embodiment;

[0055] Fig. 11b is an amplified sectional view of a part of the injector valve of Fig. 1 illustrating the arrangement of the suction valve, with the sectional view taken at a 180 degree angle relative to the sectional view of Fig. 11a, and at a distance to a centre axis of the injector valve, according to an example embodiment;

[0056] Fig. 12a is an outer side view of the suction valve of Figs. 2 and 3 according to an example embodiment;

[0057] Fig. 12b is a perspective view of the suction valve of Fig. 12a according to an example embodiment;

[0058] 03786-PCT Fig. 13a is a perspective view of a suction valve piston for use in the suction valve of Figs. 2 and 3 according to an example embodiment;

[0059] Fig. 13b is a side view of the suction valve piston of Fig. 13a according to an example embodiment;

[0060] Fig. 14 is a longitudinal sectional view of the suction valve of Figs. 2 and 3 when placed in a test unit with the suction valve in closed position according to an example embodiment;

[0061] Fig. 15 is a longitudinal sectional view of the suction valve of Figs. 2 and 3 when placed in a test unit with the suction valve in open position according to an example embodiment;

[0062] Figs. 16a, 16b, and 16c show different cut-through views of the suction valve and test unit of Fig. 15 according to example embodiments;

[0063] Fig. 17 is a perspective view of a connection piece for replacing the suction valve in the valve unit of Fig. 1 for testing purpose, which is not part of the invention and which is present for illustration purposes only; and

[0064] Fig. 18 is a longitudinal sectional view of the valve unit of Fig. 1 with the connection piece of Fig. 17 replacing the suction valve for testing purpose, which is not part of the invention and which is present for illustration purposes only.

[0065] LIST OF REFERENCE NUMBERS FOR THE DRAWINGS

[0066] Injector valve 100

[0067] Injector valve body 101a

[0068] Injector valve oil port 101b

[0069] Injector valve body lid 101c

[0070] Injector valve piston 102

[0071] Injector valve piston chamber 103

[0072] Nozzle valve 104a

[0073] Nozzle valve spring 104b

[0074] 03786 PCT Nozzle valve piston 105

[0075] Nozzle valve piston seat 106

[0076] Nozzle valve piston connection 107

[0077] Nozzle valve opening 108

[0078] Sealing oil channel 109

[0079] First piston chamber inlet channel 110a

[0080] Second piston chamber inlet channel 110b

[0081] First piston chamber outlet channel 111a

[0082] Second piston chamber outlet channel 111b

[0083] Suction valve receipt chamber 112a

[0084] First fuel chamber 112b

[0085] Nozzle valve fuel channel 113

[0086] Second fuel chamber 114

[0087] Sealing oil inlet 115

[0088] First sealing oil chamber 116

[0089] Second sealing oil chamber 117

[0090] Injector valve piston upper seal 118

[0091] Injector valve piston lower seal 119

[0092] Injector valve piston clearance 120

[0093] First venting channel 121

[0094] Second venting channel 122

[0095] Venting chamber 123

[0096] Third venting channel 124

[0097] Suction valve 200

[0098] Suction valve body 201

[0099] Suction valve piston chamber 202

[0100] Suction valve inlet opening 203

[0101] Suction valve outlet opening 204

[0102] Suction valve spring 205

[0103] Suction valve piston 206

[0104] Piston valve seat 207

[0105] Suction valve connection 208

[0106] Upper valve fluid channel 209

[0107] 03786-PCT Lower valve fluid channel 210

[0108] Suction valve bottom recess 211

[0109] Suction valve piston bottom part 212

[0110] Suction valve piston recess 213

[0111] Suction valve piston fluid channels 214

[0112] Suction valve sealing ring 215

[0113] Test unit 300

[0114] Test chamber 301

[0115] Lower test chamber clearance 301a

[0116] Middle test chamber clearance 301b

[0117] Upper test chamber clearance 301c

[0118] Test oil inlet 302a

[0119] Test oil inlet channel 302b

[0120] Test oil outlet 303a

[0121] Test oil outlet channel 303b

[0122] Test unit lid 304

[0123] Test unit piston 305

[0124] Lid channel 306

[0125] Injector valve test piece 400

[0126] Test piece oil inlet 401

[0127] Test piece oil outlet 402

[0128] DETAILED DESCRIPTION

[0129] A new Fuel Booster Injector Valve for Ammonia or Methanol, FBIV-A / M, for a two-stroke combustion engine has been developed by MAN Energy Solutions. During normal operation, the injector valve is supplied with sealing oil, high pressure hydraulic oil, and liquid fuel. Sealing oil is to prevent internal leak of liquid fuel from entering unintended areas of the injector valve. The liquid fuel is supplied via a Safety Suction Valve, SSV, to a piston chamber. The high pressure hydraulic oil is acting on top of a piston to increase or boost the pressure of the liquid fuel within the piston chamber to an injection pressure for which the injection valve, FBIV-A / M, opens and fuel is injected.

[0130] 03786-PCT During normal operation, the sealing oil is supplied at a pressure around 110 bar, the liquid fuel is supplied at a pressure around 80 bar, and the hydraulic oil acting to boost the pressure of the liquid fuel is supplied at a pressure around 315 bar.

[0131] An embodiment of the injector valve 100, an embodiment of a suction valve 200, an embodiment of a test unit 300 for testing the suctions valve 200, and an injector valve test piece 400 used for testing the injector valve 100 are described in the following with reference to Figs. 1 to 18.

[0132] The injector valve 100 holds an injector valve body 101a and a suction valve 200 for receiving liquid fuel. The injector valve 100 can be divided into an upper pump barrel section A and a lower fuel valve section B, see Fig. 1.

[0133] For the pump barrel section A, the injector valve body 101a holds an injector valve piston chamber 103 holding an injector valve piston 102, an injector valve body lid 101c with an injector valve oil port 101b for receiving pressurized oil for movement of the injector valve piston 102, a suction valve receipt chamber 112a for receipt of a suction valve 200, a first fuel chamber 112b being fluidly connected to the suction valve receipt chamber 112a, first and second piston inlet channels 110a, 110b, see Fig. 5, providing a fluid connection from the suction valve receipt chamber 112a to the injector valve piston chamber 103, first and second piston outlet channels 111a, 111b, see Fig. 4, providing a fluid connection from the injector valve piston chamber 103 to the first fuel chamber 112b via the suction valve receipt chamber 112a.

[0134] For the fuel valve section B, the injector valve body 101a holds a nozzle valve 104a having a nozzle valve piston 105 with a nozzle valve piston seat 106, a nozzle valve spring 104b, a nozzle valve connection 107, and a nozzle valve opening 108. A second fuel chamber 114 and a nozzle valve fuel channel 113, see Figs.5 and 6, are arranged for providing for a fluid connection from the first fuel chamber 112b to the second fuel chamber 114, see Fig. 5, whereby compressed fuel received in the second fuel chamber 114 may lift the nozzle valve piston 105 against the nozzle valve spring 104b and thereby lifting the nozzle valve piston seat 106 from the nozzle valve connection 107 to open the nozzle valve 104a, whereby compressed fuel may flow from the first fuel chamber 112b via the nozzle valve

[0135] 03786-PCT fuel channel 113 and the second fuel chamber 114 an out from the nozzle valve opening 108 when the compressed fuel is supplied at a pressure above a nozzle valve opening pressure for which the nozzle valve 104a is configured to start opening by lifting the nozzle valve piston seat 105 from the nozzle valve connection 107.

[0136] The sealing oil is supplied to a sealing oil inlet 115, see Fig. 7, from where sealing oil is supplied to first and second sealing oil chambers, 116 and 117, via a sealing oil channel 109, see Fig. 7 and 8. An injector valve piston upper seal 118 and an injector valve lower seal 119 are provided for securing a tight connection between the injector valve piston 102 and the injector valve piston chamber 103. An injector valve piston clearance 120 is provided to give room for the injector valve piston 102 to move within the injector valve piston chamber 103.

[0137] The injector vavle 100 holds a number of venting channel and chambers, with a first venting channel 121 being provided for venting any leakage into the injector valve piston clearance 120. A second venting channel 122 is connected to a venting chamber 123, which again is connected to a third venting channel 124, for venting the injector valve piston chamber 103.

[0138] In order to perform a test of the injector valve body 101a, which includes an opening test of the nozzle valve 104a, there is provided an injector valve test piece 400 having a test piece oil inlet 401 and a test piece oil outlet 402, see Figs. 17 and 18. The injector valve test piece 400 is configured to fit into the suction valve receipt chamber 112a. For the opening test of the nozzle valve, the suction valve 200 is removed from the suction valve receipt chamber 112a and replaced by the injector valve test piece 400. When a test oil is supplied to the test piece oil inlet 401 , the oil is conducted from the test piece oil outlet 402 into the first fuel chamber 112b and via the via the nozzle valve fuel channel 113 into the second fuel chamber 114. When test oil is supplied at a pressure being higher than an opening pressure of the nozzle valve 104a, the test oil flows from the first fuel chamber 112b via the nozzle valve fuel channel 113 to the second fuel chamber 114, from where the compressed test oil lifts the nozzle valve piston 105 against the nozzle valve spring 104b and thereby lifts the nozzle valve piston seat 106 from the nozzle valve connection 107 to open the nozzle valve 104a, whereby compressed test oil flows out from the nozzle valve opening 108. The injector valve test piece 400 of Fig. 17 and the test of the injector

[0139] 03786-PCT valve body 101a, which includes an opening test of the nozzle valve 104a, for which the injector valve test piece 400 replaces the suction valve 200, are not according to the invention and are present for illustration purposes only.

[0140] An embodiment of the suction valve 200 is illustrated in Figs. 2, 3, 12a, 12b, 13a and 13b. Here, fig. 2 is a longitudinal sectional view of the suction valve 200 in closed position, Fig. 3 is a longitudinal sectional view of the suction valve 200 in open position, Fig. 12a is an outer side view of the suction valve 200, Fig. 12b is a perspective view of the suction valve 200, Fig. 13a is a perspective view of a suction valve piston 206 being part of the suction valve 200, and Fig. 13b is a side view of the suction valve piston 206.

[0141] The suction valve 200 has a suction valve body 201 surrounding a suction valve piston chamber 202 with a suction valve inlet opening 203 at the top and a suction valve outlet opening 204 at the bottom. The suction valve piston chamber 202 holds a suction valve spring 205 and a suction valve piston 206, where the suction valve piston 206 has a piston valve seat 207 formed at an upper end of the suction valve piston 206, and a suction valve connection 208 is formed at an upper end of the suction valve piston chamber 202 for receiving the piston valve seat 207 when the suction valve is in closed position. The suction valve piston chamber 202 also holds a bottom recess 211 formed at a lower end of the suction valve piston chamber 202 for receiving a bottom part 212 of the suction valve piston 206 when the suction valve is in open position. The suction valve body 201 holds a number of upper valve fluid channels 209, which provide a fluid connection from the suction valve piston chamber 202 to outer wall parts of an upper part of the suction valve body 201. The suction valve body 201 also holds a number of lower valve fluid channels 210, which provide a fluid connection from the suction valve piston chamber 202 to outer wall parts of a lower part of the suction valve body 201. A suction valve sealing 215 is provided at an upper and outer wall part of the suction valve body 201 , to thereby secure a tight connection when inserting the suction valve 200 into the suction valve receipt chamber 112a of the injector valve body 101a.

[0142] The bottom part 212 of suction valve piston 206 holds a suction valve piston recess 213 and a number of narrow suction valve piston fluid channels 214. When the suction valve 200 is open, the bottom part 212 of suction valve piston 206 is received at the suction valve bottom recess 211 and a fluid passage is provided from the suction valve outlet

[0143] 03786-PCT opening 204 to the outer wall parts of the lower part of suction valve body 201 via the suction valve piston recess 213 and the suction valve piston channels 214.

[0144] When the suction valve 200 is open, the suction valve piston 206 compresses the suction valve spring 205, and the piston valve seat 207 is positioned below the suction valve connection 208, thereby providing a fluid connection from the suction valve inlet opening 203 to the outer wall parts of the upper part of the suction valve body 201 via the upper valve fluid channels 209. When the suction valve 200 is open, the bottom part 212 of suction valve piston 207 is received at the bottom recess 211, thereby providing a closure for a fluid connection via the lower valve fluid channels 210 from the suction valve outlet opening 204 to the outer wall parts of the lower part of suction valve body 201 . When the suction valve 200 is open with the fluid connection via the lower valve fluid channels 210 being closed, a minor fluid passage is provided from the suction valve outlet opening 204 to the outer wall parts of the lower part of suction valve body 201 via the suction valve piston recess 213 and the suction valve piston channels 214.

[0145] When the suction valve 200 is closed, the piston valve seat 207 is received by the suction valve connection 208 due to the pressure from the suction valve spring 205 on the suction valve piston 206, thereby providing a closure to the fluid connection from the suction valve inlet opening 203 to the outer wall parts of the suction valve body 201 via the upper valve fluid channels 209. When the suction valve 200 is closed, the bottom part 212 of the suction valve piston 207 is positioned above the bottom recess 211, thereby providing a fluid connection from the suction valve outlet opening 204 to the outer wall parts of the lower part of suction valve body 201 via the lower valve fluid channels 210, while the minor fluid passage via the suction valve piston recess 213 and the suction valve piston channels 214 from the suction valve outlet opening 204 to the outer wall parts of the lower part of suction valve body 201 is closed.

[0146] During normal operation, the suction valve 200 is inserted into the injector valve 100. This is illustrated in Figs. 9, 10, 11a, and 11 b, for which Fig. 9 is an amplified sectional view of a part of the injector valve 100, illustrating the arrangement of the suction valve 200, with the sectional view taken at the centre of the injector valve 100, while Fig. 10 is an amplified sectional view of a part of the injector valve 100, illustrating the arrangement of the suction valve 200, with the sectional view taken at a distance to a centre axis of the injector valve.

[0147] 03786-PCT Fig. 11a is an amplified sectional view of a part of the injector valve 100, illustrating the arrangement of the suction valve 200, with the sectional view taken at a 90 degree angle relative to the sectional views of Figs. 1 and 9, and at a distance to a centre axis of the injector valve, while Fig. 11b is an amplified sectional view of a part of the injector valve 100, illustrating the arrangement of the suction valve, with the sectional view taken at a 180 degree angle relative to the sectional view of Fig. 11a, and at a distance to a centre axis of the injector valve.

[0148] Figs. 9, 10, 11a, and 11b illustrate how the first and second piston inlet channels 110a and 110b are positioned to provide fluid passages from the upper valve fluid channels 209 of the suction valve 200 to the injector valve piston chamber 103. The two inlet channels 110a and 110b are positioned on opposite sides of the dashed line A of Fig. 9. It is also illustrated in Figs. 9, 10, 11a, and 11b how the first and second piston outlet channels 111a and 111b are positioned to provide fluid passages from the injector valve piston chamber 103 to the lower valve fluid channels 210 of the suction valve. The two outlet channels 111a and 111 b are positioned on opposite sides of the dashed line B of Fig. 9.

[0149] During normal operation, then when the hydraulic oil pressure to the injector valve oil port 101 b and thereby to the injector valve piston 102 is controlled to be off or very low, a pressure of fuel to be injected is supplied at 80 bar to the suction valve inlet opening 203. The 80 bar is above the suction valve fuel opening pressure, and the suction valve 200 is open and fuel is supplied to the injector valve piston chamber 103 from the suction valve inlet opening 203 via the upper valve fluid channels 209 and the first and second piston inlet channels 110a and 110b. When the hydraulic oil pressure on the injector valve oil port 101b and the injector valve piston 102 is controlled to be on, the pressure on the injector valve piston 102 is set to be about 315 bar, which is well above the fuel pressure of 80 bar at the suction valve inlet opening 203, whereby the suction valve 200 closes. With a pressure of 315 bar the injector valve piston 102 is moved and compresses the fuel in the injector valve piston chamber 103 into the suction first fuel chamber 112b via the first and second piston outlet channels 111a and 111 b and via the lower valve fluid channels 210 of the suction valve 200. From the first fuel chamber 112b the compressed fuel flows via the nozzle valve fuel channel 113 into the second fuel chamber 114. The compressed fuel of the second fuel chamber 114 lifts the nozzle valve piston 105 from the

[0150] 03786-PCT nozzle valve piston seat 106 against the nozzle valve spring 104b to open the nozzle valve 104a, and fuel is sprayed out through the nozzle valve opening 108.

[0151] In order to perform a test of the suction valve 200, which includes a leakage test of the suction valve 200, there is provided a test unit 300 having a test chamber 301. During the test, the suction valve 200 is placed in the test chamber 301 as illustrated in Figs. 14, 15, 16a, 16b and 16c. Here, Fig. 14 is a longitudinal sectional view showing the suction valve 200 placed in the test unit chamber 301 , with the suction valve 200 in closed position, and Fig. 15 is a longitudinal sectional view showing the suction valve 200 placed in the test unit chamber 301 , with the suction valve 200 in open position. Figs. 16a, 16b, and 16c show different cut-through views of the suction valve 200 placed in the test chamber 301.

[0152] The test unit 300 holds the test chamber 301 , a test unit lid 304 with a test unit piston 305, a test oil inlet 302a and a test oil inlet channel 302b reaching a bottom part of the test chamber 301 , and a test oil outlet 303a and a test oil outlet channel 303b reaching an upper part of the test chamber 301.

[0153] For testing the suction valve 200, the suction valve 200 is placed in the test unit chamber 301 , with the test unit lid 304 covering the suction valve 200 with the test unit piston 305 positioned for engagement of the suction valve piston 206, whereby the test unit piston can be pressed down on the suction valve piston 206 in order to open the suction valve 200. The test unit 300 is configured to provide a fluid connection from the test oil inlet 302a to the suction valve outlet opening 204 via the test oil inlet channel 302b. Also, a fluid connection is provided from the test oil outlet 303a to the suction valve inlet opening 203 via the test oil outlet channel 303b and a lid channel 306 formed between an upper part of the suction valve body 201 holding the suction valve inlet opening 203 and the test unit lid 304 providing a closure to an upper part of the test chamber 301. The suction valve 200 is arranged within the test chamber 301 , such that a tight closure is provided between an upper part of the suction valve body 201 and an upper part of the test chamber 301 , which tight closure is provided above the upper valve fluid channels 209. The suction valve 200 is also arranged within the test chamber 301 , such that a test chamber clearance 301a, b,c is provided between the outer wall parts of the suction valve body 201 and the wall parts of the test chamber 301 , thereby providing a fluid connection from the lower

[0154] 03786-PCT valve fluid channels 210 via the test chamber clearance 301a, b,c to the to the upper valve fluid channels 209.

[0155] The test chamber clearance 301a,b,c comprises a lower test chamber clearance 301a, a middle test chamber clearance 301b, and an upper test chamber clearance 301c as illustrated in Fig. 15. Fig. 16a shows a cut-through view of the suction valve 200 placed in the test chamber 301 , where the cut is taken along the line marked KK in Fig. 15 showing the upper test chamber clearance 301c. Fig. 16b shows a cut-through view of the suction valve 200 placed in the test chamber 301 , where the cut is taken along the line marked JJ in Fig. 15 showing the middle test chamber clearance 301b. Fig. 16c shows a cut-through view of the suction valve 200 placed in the test chamber 301 , where the cut is taken along the line marked HH in Fig. 15 showing the lower test chamber clearance 301a. The lower test chamber clearance 301a provides a clearance, which fully surrounds the lower valve fluid channels 210, and the upper test chamber clearance 301c provides a clearance, which fully surrounds the upper valve fluid channels 209. However, the middle test chamber clearance 301 b holds two opposed clearances, which together partly surrounds the suction valve body 201 , too thereby allow a stable connection between parts of the suction valve body 201 and the walls of the test chamber 301.

[0156] Test of the suction valve 200

[0157] The purpose of the test is:

[0158] 1. To verify that the suction valve 200 is tight when in the closed position and can stand a high oil pressure at the outlet opening 204 corresponding to the high fuel pressure obtained from the injector valve piston chamber 103 during normal operation.

[0159] 2. To verify that the suction valve piston 206 can be moved from open to close position by the spring force from the suction valve spring 205.

[0160] 3. To verify that fuel oil can pass through the suction valve 200 in open position.

[0161] To verify whether the suction valve 200 is tight, a suction valve leakage test is performed, which comprises: a) securing that the suction valve 200 is placed in the test chamber 301 in closed position, whereby the suction valve piston seat 207 is received by the suction valve connection 208 due to pressure from the suction vale spring 205;

[0162] 03786-PCT b) supplying test oil at a first test oil pressure to the test oil inlet 302a, where the first test oil pressure is above a fuel oil opening pressure for which the suction valve 200 is configured to start opening by moving the piston valve seat 207 below the suction valve connection 208; and c) checking if any test oil reaches out through the test oil outlet 303a.

[0163] The test oil supplied at the test oil inlet 302a runs through the test oil inlet channel 302b into the suction valve outlet opening 204, through the lower valve fluid channels 210, through the test chamber clearance 301a,b,c, and into the upper valve fluid channels 209, where the test oil is stopped by the closure provided by the suction valve piston seat 207 being received by the suction valve connection 208. If there is any leakage, part of the test oil will pass the between the suction valve piston seat 207 and the suction valve connection 208 into the suction valve inlet opening 203, through the lid channel 306 and the test oil outlet channel 303b and out via the test oil outlet 303a.

[0164] Thus, if any test oil is observed reaching out through the test oil outlet 303a, there is a leak in the suction valve.

[0165] When placing the suction valve 200 within the test chamber 301 , it is preferred that a tight closure is obtained between upper and a lower parts of the suction valve body 201 and upper and lower parts of the test chamber 301 .

[0166] The step of securing that the suction valve 200 placed in the test chamber 301 is in closed condition may comprise securing that no outer pressure being above the fuel oil opening pressure is supplied to the suction valve piston 206.

[0167] For the present suction valve, the fuel oil opening pressure is in the range of 2-20 bar, such as around 2,5 bar or around 5 bar.

[0168] It is preferred that the first test oil pressure is substantially higher than the fuel oil opening pressure, such as at least two, three, four or five times the first fuel opening pressure, or such as at least ten or twenty times the first oil opening pressure. For the present test it is preferred that the first test oil pressure is in the range of 100 to 400 bar, such as about 300 bar.

[0169] 03786-PCT To verify whether the suction valve piston 206 can be moved from open to close position by the spring force from the suction valve spring 205, a suction valve piston test may be performed, which comprises: aa) providing a movement of the test unit piston 305 to engage with the suction valve piston 206 at a first position, and further providing a pressure on the test unit piston 305 and thereby the suction valve piston 206 to overcome a spring force provided by the suction valve spring 205, whereby the test unit piston 305 and the suction valve piston 206 are moved a first length from the first position; bb) release the pressure on the test unit piston 305 and thereby the pressure on the suction valve piston 206; and cc) observing whether the test unit piston (305) returns to the first position.

[0170] To verify that fuel oil can pass through the suction valve 200 in its open position, a suction valve open test may be performed, which suction valve open test comprises: aaa) providing a test unit pressure on the test unit piston 305 and thereby the suction valve piston 206, said test unit pressure being higher than the fuel oil opening pressure to overcome a spring force provided by the suction valve spring 205, whereby the test unit piston 305 and the suction valve piston 206 holding the piston valve seat 207 are moved into an end position in which the suction valve 200 is fully open; bbb) maintaining the test unit pressure on the test unit piston 305 to hold the suction valve piston 206 in the end position; ccc) supplying test oil at a second test oil pressure to the test oil inlet 302a, said second test oil pressure being below the difference between the test unit pressure provided to the test unit piston 305 and the fuel oil opening pressure; ddd) checking if any test oil reaches out through the test oil outlet 303a; and eee) release the pressure on the test unit piston 305 and the pressure on the suction valve piston 206, thereby closing the suction valve.

[0171] When the suction valve 200 is open, the fluid connection via the lower valve fluid channels 210 is closed, and test oil supplied to the test oil inlet 302a flows via the test oil inlet channel 302b into the suction valve outlet opening 204, then via the suction valve piston recess 213 and the suction valve piston channels 214 into the lower test chamber clearance 301a, then via middle and upper test chamber clearances 301 b and 301c into

[0172] 03786-PCT the upper valve fluid channels 209 into the suction valve inlet opening 203, then through the lid channel 306 and the test oil outlet channel 303b and out from the test oil outlet 303a.

[0173] If any test oil is observed reaching out through the test oil outlet 303a, then the suction valve is open. When releasing the pressure on the test unit piston 305 and thereby the pressure on the suction valve piston 206, the spring force from the suction valve spring 205 forces the piston valve seat 207 into connection with the suction valve connection 208, thereby closing the suction valve.

[0174] For a suction valve having a fuel oil opening pressure around 2,5 bar or around 5 bar, then for the suction valve open test it is preferred that the provided test unit pressure on the test unit piston 305 is at least 15 bar, and that the second test oil pressure is around 5 bar. Thus, a long as the test unit pressure is maintained at least at 15 bar and the second test oil pressure is around 5 bar, the suction valve is in the open position.

[0175] The suction valve open test may be followed by a suction valve leakage test by adding the following steps: fff) increasing the pressure of the supplied test oil to a third test oil pressure being substantially higher than the fuel oil opening pressure; and ggg) checking if any test oil reaches out through the test oil outlet 303a.

[0176] If any test oil is observed reaching out through the test oil outlet 303a, there is a leak in the suction valve.

[0177] It is preferred that the third test oil pressure is substantially higher than the fuel oil opening pressure, such as at least two, three, four or five times the first fuel opening pressure, or such as at least ten or twenty times the first oil opening pressure. For the present test it is preferred that the third test oil pressure is in the range of 100 to 400 bar, such as about 300 bar. Thus, the third test oil pressure may be equal to the first test oil pressure.

[0178] Test of the injector valve body 101a

[0179] 03786-PCT The test of the injector valve body 101a is not according to the invention and is present for illustration purposes only.

[0180] The purpose of this test is to verify that the nozzle valve 104a opens and also to observe the actual opening pressure of the nozzle valve 104a.

[0181] The test of the injector valve body 101a of the injector valve 100 comprises: inserting an injector valve test piece 400 into the suction valve receipt chamber 112a, said injector valve test piece 400 being configured to fit into the suction valve receipt chamber 112a and having a test piece oil inlet 401 and a test piece oil outlet 402, whereby oil supplied to the test piece oil inlet 401 is received from the test piece oil outlet 402 into the first fuel chamber 112b and via the via the nozzle valve fuel channel 113 into the second fuel chamber 114; supplying a test piece oil at a first test piece oil pressure to the first test piece oil inlet, said test piece oil pressure being below a nozzle valve opening pressure for which the nozzle valve 104a is configured to start opening by lifting the nozzle valve piston seat 105 from the nozzle valve connection 107; increasing the oil pressure of the supplied test piece oil; and observing the pressure of the supplied test piece oil for which test piece oil starts spraying out from the nozzle valve opening 108.

[0182] For the present injector valve, the opening pressure for the nozzle valve may be in the range of about 350 to 450 bar, such as in the range of about 370 to 430 bar. The first test piece oil pressure may therefore be below 350 bar, such as below 330 bar, and the oil pressure of the test piece oil may be increased from below 350 bar, such as from below 330 bar to above 430 bar, such as to above 450 bar.

[0183] The invention has been described in conjunction with various embodiments herein. However, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality.

[0184] 03786-PCT

Claims

CLAIMS1. A method of testing a suction valve (200) for an injector valve (100), with the suction valve being placed in a test chamber (301) of a test unit (300), wherein the suction valve has: a suction valve body (201) surrounding a suction valve piston chamber (202) with a suction valve inlet opening (203) at a top and a suction valve outlet opening (204) at a bottom, which suction valve piston chamber holds a suction valve spring (205) and a suction valve piston (206), said suction valve piston (206) having a piston valve seat (207) formed at an upper end of the suction valve piston, said suction valve piston chamber holding a suction valve connection (208) formed at an upper end of the suction valve piston chamber (202) for receiving the piston valve seat (207) when the suction valve is in closed position, and said suction valve piston chamber holding a bottom recess (211) formed at a lower end of the suction valve piston chamber (202) for receiving a bottom part (212) of the suction valve piston (206) when the suction valve is in open position; said valve body (201) having one or more upper valve fluid channels (209) providing a fluid connection from the suction valve piston chamber (202) to outer wall parts of an upper part of the suction valve body (201); and said valve body (201) having one or more lower valve fluid channels (210) providing a fluid connection from the suction valve piston chamber (202) to outer wall parts of a lower part of the suction valve body (201); wherein, when the suction valve (200) is open, the piston valve seat (207) is positioned below the suction valve connection (208), thereby providing a fluid connection from the suction valve inlet opening (203) to the outer wall parts of the upper part of the suction valve body (201) via the upper valve fluid channels (209), and the bottom part (212) of suction valve piston (206) is received at the bottom recess (211), thereby providing at least a partly closure for a fluid connection from the suction valve outlet opening (204) to the outer wall parts of the lower part of suction valve body (201) via the lower valve fluid channels (210); wherein, when the suction valve (200) is closed, the piston valve seat (207) is received by the suction valve connection (208), thereby providing a closure to the fluid connection from the suction valve inlet opening (203) to the outer wall parts of the suction valve body (201) via the upper valve fluid channels (209), and the bottom part (212) of the suction valve piston (206) is positioned above the bottom recess (211), thereby providing03786-PCTa fluid connection from the suction valve outlet opening (204) to the outer wall parts of the lower part of suction valve body (201) via the lower valve fluid channels (210); wherein the test unit (300) holds a test oil inlet (302a) being fluidly connected to the suction valve outlet opening (204) via a test oil inlet channel (302b), said test unit (300) further holding a test oil outlet (303a) being fluidly connected to the suction valve inlet opening (203) via a test oil outlet channel (303b) being formed between an upper part of the suction valve body (201) holding the suction valve inlet opening (203) and a test unit lid (304) providing a closure to an upper part of the test chamber (301); wherein a tight closure is provided between an upper part of the suction valve body (201) and an upper part of the test chamber (301), said tight closure being provided above the upper valve fluid channels (209); wherein a test chamber clearance (301a,b,c) is provided between the outer wall parts of the suction valve body (201) and the wall parts of the test chamber (301), thereby providing a fluid connection from the lower valve fluid channels (210) via the test chamber clearance (301a,b,c) to the to the upper valve fluid channels (209); and wherein said method of testing a suction valve (200) comprises a suction valve leakage test, which comprises: securing that the suction valve (200) placed in the test chamber (301) is in closed position, whereby the suction valve piston seat (207) is received by the suction valve connection (208) due to pressure from the suction valve spring (205); supplying test oil at a first test oil pressure to the test oil inlet (302a), said first test oil pressure being above a fuel oil opening pressure for which the suction valve (200) is configured to start opening by moving the piston valve seat (207) below the suction valve connection (208); and checking if any test oil reaches out through the test oil outlet (303a).

2. A method according to claim 1 , wherein the step of securing that the suction valve (200) placed in the test chamber (301) is in closed condition comprises securing that no outer pressure being above the fuel oil opening pressure is supplied to the suction valve piston (206).

3. A method according to claim 1 or 2, wherein the first test oil pressure is substantially higher than the fuel oil opening pressure, such as at least two, three, four or five times the first fuel opening pressure.03786-PCT4. A method according to any one of the claims 1 to 3, wherein the first test oil pressure is substantially higher than the fuel oil opening pressure, such as at least ten or twenty times the first oil opening pressure.

5. A method according to any one of the claims 1 to 4, wherein the fuel oil opening pressure of the suction valve is in the range of about 2 to 20 bar, and the first test oil pressure is in the range of 100 to 400 bar, such as about 300 bar.

6. A method according to any one of the claims 1 to 5, wherein the test unit lid (304) holds a test unit piston (305) positioned for engagement of the suction valve piston (206) when the suction valve (200) is placed in the test chamber (301) of the test unit (300), and wherein said method of testing the suction valve further comprises a suction valve piston test, said suction valve piston test comprising: providing a movement of the test unit piston (305) to engage with the suction valve piston (206) at a first position, and further providing a pressure on the test unit piston (305) and thereby the suction valve piston (206) to overcome a spring force provided by the suction valve spring (205), whereby the test unit piston (305) and the suction valve piston (206) are moved a first length from the first position; release the pressure on the test unit piston (305) and thereby the pressure on the suction valve piston (206); and observing whether the test unit piston (305) returns to the first position.

7. A method according to any one of the claims 1 to 6, wherein the test unit lid (304) holds a test unit piston (305) positioned for engagement of the suction valve piston (206) when the suction valve (200) is placed in the test chamber (301) of the test unit (300), wherein a bottom part (212) of suction valve piston (206) holds a suction valve piston recess (213) and a number of narrow suction valve piston fluid channels (214), wherein, when the suction valve (200) is open, the bottom part (212) of suction valve piston (206) is received at the bottom recess (211) and a fluid passage is provided from the suction valve outlet opening (204) to the outer wall parts of the lower part of suction valve body (201) via the suction valve piston recess (213) and the suction valve piston channels (214); and wherein said method of testing the suction valve further comprises a suction valve open test, said suction valve open test comprising:03786-PCTproviding a test unit pressure on the test unit piston (305) and thereby the suction valve piston (206), said test unit pressure being higher than the fuel oil opening pressure to overcome a spring force provided by the suction valve spring (205), whereby the test unit piston (305) and the suction valve piston (206) holding the piston valve seat (207) are moved into an end position in which the suction valve (200) is fully open; maintaining the test unit pressure on the test unit piston (305) to hold the suction valve piston (206) in the end position; supplying test oil at a second test oil pressure to the test oil inlet (302a), said second test oil pressure being below the difference between the test unit pressure provided to the test unit piston (305) and the fuel oil opening pressure; checking if any test oil reaches out through the test oil outlet (303a); and release the pressure on the test unit piston (305) and the pressure on the suction valve piston (206), thereby closing the suction valve.

8. A method according to claim 7, further comprising the step of increasing the pressure of the supplied test oil to a third test oil pressure being substantially higher than the fuel oil opening pressure; and checking if any test oil reaches out through the test oil outlet (303a).

9. A method according to claim 8, wherein the fuel oil opening pressure of the suction valve is in the range of about 2-20 bar, and the third test oil pressure is in the range of 100 to 400 bar, such as about 300 bar.

10. A method according to any one of the claims 1 to 9, wherein the suction valve body (201) is placed in the test chamber (301) with a bottom part of the section valve body (201) resting on a bottom part of the test chamber (301).

11. A method according to claim 10, wherein the suction valve body (201 ) and the test chamber (301) are configured for providing a tight closure between a lower part of the suction valve body (201) and a lower part of the test chamber (301).

12. A system for testing a suction valve (200) for use by an injector valve (100), said system comprising a test unit (300) with a test chamber (301) and the suction valve (200),03786-PCTsaid suction valve (200) being placed in the test chamber (301), wherein the suction valve has: a suction valve body (201) surrounding a suction valve piston chamber (202) with a suction valve inlet opening (203) at a top and a suction valve outlet opening (204) at a bottom, which suction valve piston chamber holds a suction valve spring (205) and a suction valve piston (206), said suction valve piston (206) having a piston valve seat (207) formed at an upper end of the suction valve piston, said suction valve piston chamber holding a suction valve connection (208) formed at an upper end of the suction valve piston chamber (202) for receiving the piston valve seat (207) when the suction valve is in closed position, and said suction valve piston chamber holding a bottom recess (211) formed at a lower end of the suction valve piston chamber (202) for receiving a bottom part (212) of the suction valve piston (206) when the suction valve is in open position; said valve body (201) having one or more upper valve fluid channels (209) providing a fluid connection from the suction valve piston chamber (202) to outer wall parts of an upper part of the suction valve body (201); and said valve body (201) having one or more lower valve fluid channels (210) providing a fluid connection from the suction valve piston chamber (202) to outer wall parts of a lower part of the suction valve body (201); wherein, when the suction valve (200) is open, the piston valve seat (207) is positioned below the suction valve connection (208), thereby providing a fluid connection from the suction valve inlet opening (203) to the outer wall parts of the upper part of the suction valve body (201) via the upper valve fluid channels (209), and the bottom part (212) of suction valve piston (206) is received at the bottom recess (211), thereby providing at least a partly closure for a fluid connection from the suction valve outlet opening (204) to the outer wall parts of the lower part of suction valve body (201) via the lower valve fluid channels (210); wherein, when the suction valve (200) is closed, the piston valve seat (207) is received by the suction valve connection (208), thereby providing a closure to the fluid connection from the suction valve inlet opening (203) to the outer wall parts of the suction valve body (201) via the upper valve fluid channels (209), and the bottom part (212) of suction valve piston (206) is positioned above from the bottom recess (211), thereby providing a fluid connection from the suction valve outlet opening (204) to the outer wall parts of the lower part of suction valve body (201) via the lower valve fluid channels (210); wherein the test unit (300) holds a test oil inlet (302a) being fluidly connected to the suction valve outlet opening (204) via a test oil inlet channel (302b), said test unit (300)03786-PCTfurther holding a test oil outlet (303a) being fluidly connected to the suction valve inlet opening (203) via a test oil outlet channel (303b) being formed between an upper part of the suction valve body (201) holding the suction valve inlet opening (203) and a test unit lid (304) providing a closure to an upper part of the test chamber (301); wherein a tight closure is provided between an upper part of the suction valve body (201) and an upper part of the test chamber (301), said tight closure being provided above the upper valve fluid channels (209); and wherein a test chamber clearance (301a,b,c) is provided between the outer wall parts of the suction valve body (201) and the wall parts of the test chamber (301), thereby providing a fluid connection from the lower valve fluid channels (210) via the test chamber clearance (301a,b,c) to the to the upper valve fluid channels (209).

13. A system according to claim 12, wherein the test chamber clearance comprises a lower test chamber clearance (301a), a middle test chamber clearance (301 b), and an upper test chamber clearance (301c).

14. A system according to claim 13, wherein the middle test chamber clearance (301 b) holds two opposed clearances, which together partly surrounds the suction valve body (201).

15. A system according to claim 13 or 14, wherein the lower test chamber clearance (301a) provides a clearance, which fully surrounds the one or more lower valve fluid channels (210), and wherein the upper test chamber clearance (301c) provides a clearance, which fully surrounds the one or more upper valve fluid channels (209).

16. A system according to any one of the claims 12 to 15, wherein the test unit lid (304) holds a test unit piston (305) positioned for engagement of the suction valve piston (206) when the suction valve (200) is placed in the test chamber (301) of the test unit (300).

17. A system according to any one of the claims 12 to 16, wherein a bottom part (212) of suction valve piston (206) holds a suction valve piston recess (213) and a number of narrow suction valve piston fluid channels (214), wherein, when the suction valve (200) is open, the bottom part (212) of suction valve piston (206) is received at the bottom recess (211) and a fluid passage is provided from the suction valve outlet opening (204) to the03786-PCTouter wall parts of the lower part of suction valve body (201) via the suction valve piston recess (213) and the suction valve piston channels (214).03786 PCT

Images