Knitted fabric cold-pad batch dyeing equipment

Abstract

The invention relates to knitted fabric cold-rolling batch dyeing equipment which comprises a cold-rolling assembly, a dyeing assembly and a cold-rolling assembly, and the cold-rolling assembly comprises a tightening mechanism and a dipping mechanism which are matched with each other; the tightening mechanism at least comprises a supporting frame, a cloth tightening device installed on the supporting frame, a multi-edge cloth guide roller installed on the supporting frame, and a scutching roller installed on the supporting frame and located between the cloth tightening device and the multi-edge cloth guide roller. The first transition roller is arranged on the support frame and is positioned below the multi-edge cloth guide roller; the second transition roller is arranged on the support frame and is positioned below the first transition roller; a liquid spraying mechanism; a cloth box; and a winding mechanism. A and B threading modes can be achieved, the device can be suitable for thick fabric and thin fabric, the defects that in the prior art, water consumption is large, and the specification of treated knitted fabric is single can be overcome, and fabric liquid obtaining is even so that the soaking effect can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of pad dyeing equipment, in particular to a cold pad heap dyeing equipment for knitted fabrics. Background Art

[0002] Cotton knit dyeing refers to the process of dyeing cotton knitted fabrics, usually using reactive dyes to improve dye uptake and dye fastness. Cotton knitted fabrics are mainly dyed with reactive dyes. After being evenly padded with dye liquor, they are curled with constant tension during the stacking process to avoid squeezing the knitted fabrics. They are then washed in a rotary drum open-width washing machine to complete the dyeing process. At present, cotton knitted fabrics are mainly dyed with overflow dye vats, which is almost an intermittent dyeing process, resulting in huge consumption of water, steam, labor, auxiliaries, dyes, etc. (for example, 1 kg of cloth usually consumes 70 to 90 kg of water).

[0003] The Chinese invention patent with application number 202310025851.0 discloses a tubular cotton knitted fabric reactive dye cold rolling pile dyeing and finishing process, in which the knitted fabric is combed and cleaned before dyeing, placed in a dyeing tank for dyeing treatment, and then lifted and leveled by a roller device, and then stacked layer by layer in a pile dyeing treatment device with manual or mechanical assistance. Under the constant temperature action of the pile dyeing treatment device, the temperature is set to about 30°C to 45°C. In response to different external production environments, the fabric is stacked flat in a stacking box and the fabric's own gravity is used for relatively soft contact to avoid uneven dyeing and finishing. Then, the rotating component is combined with the constant temperature component to effectively avoid external temperature factors and fabric edge dyeing and finishing defects in the dyeing and finishing process, thereby improving production efficiency. The constant temperature component circulates water to reduce energy loss, and the overall device is simple to operate, saving worry and effort. However, such a heap dyeing treatment device is usually only applicable to knitted fabrics of a certain specification. When knitted fabrics of different specifications need to be produced, different heap dyeing treatment devices need to be used, which is costly. Summary of the invention

[0004] The purpose of the invention is to provide a knitted fabric cold pad heap dyeing device in order to overcome the defects of the prior art that the water consumption is large and the knitted fabric specifications are single.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a knitted fabric cold pad heap dyeing device, which comprises:

[0006] A cold rolling assembly, wherein the cold rolling assembly includes a tightening mechanism and an impregnation mechanism that cooperate with each other, wherein the tightening mechanism at least includes a support frame, a cloth tightening device installed on the support frame, a multi-edge cloth guide roller installed on the support frame, an opening roller installed on the support frame and located between the cloth tightening device and the multi-edge cloth guide roller, a first transition roller installed on the support frame and located below the multi-edge cloth guide roller, and a second transition roller installed on the support frame and located below the first transition roller; the impregnation mechanism at least includes a shell, a dyeing tank installed in the shell, an impregnation roller arranged in the dyeing tank, and a first transition roller installed on the support frame. A plurality of first threaded width-opening rollers in the shell and matched with the impregnation roller and the second transition roller, a roller group arranged above one of the threaded width-opening rollers, a second threaded width-opening roller installed in the shell and located above the roller group, an open-edge blower arranged between the first transition roller and the second threaded width-opening roller and matched therewith, an active rubber roller installed on the shell and located downstream of the roller group, and a transition cylinder installed on the shell and matched with the roller group and the active rubber roller; the roller group includes a passive roller and an active roller that can rotate in both directions and match each other;

[0007] A liquid spraying mechanism, at least part of which is located above the roller group and is used for spraying dye liquid;

[0008] A cloth box, located at one side of the cold rolling assembly, for placing knitted cloth to be cold rolled;

[0009] A winding mechanism, which is located on the other side of the cold rolling assembly and is used for winding the knitted fabric.

[0010] Optimally, the tightening mechanism further comprises a plurality of tension-adjusting rollers mounted on the support frame and located between the cloth tightening device and the width-opening roller.

[0011] Optimally, the active rubber roller is a roller shaft that can rotate in both directions.

[0012] Optimally, the winding mechanism is adjustably mounted on the other side of the cold rolling assembly, and the winding mechanism includes an A-frame slidably mounted on the ground, a receiving roller mounted on the A-frame, a fabric speed detection rod mounted on one side of the A-frame, and a cylinder connected to the A-frame for pulling the A-frame to move relative to the cold rolling assembly.

[0013] Optimally, the liquid spraying mechanism includes a material trough, a material delivery pipe connected to the material trough, a dye pump installed on the material delivery pipe, a U-shaped slurry delivery pipe connected to the end of the material delivery pipe and extending to above the roller group, a spraying pipe connected to the U-shaped slurry delivery pipe, and a slurry retaining trough arranged below the spraying pipe and cooperating with the roller group.

[0014] Furthermore, the slurry retaining trough includes two arc-shaped side baffles that are spaced apart and arranged opposite to each other and an end plate connected to the ends of the two arc-shaped side baffles.

[0015] Furthermore, it also includes a liquid replenishment control component, which includes at least one group of dye tanks, at least one group of auxiliary agent tanks, at least one group of water tanks, first liquid level sensors arranged in the dye tanks, the auxiliary agent tanks and the water tanks in a one-to-one correspondence, a PLC controller communicating with the first liquid level sensor, a first liquid outlet pipe connected to the bottom of the dye tank, a second liquid outlet pipe connected to the bottom of the auxiliary agent tank and the water tank, a first pump installed on the first liquid outlet pipe and communicating with the PLC controller, a second pump installed on the second liquid outlet pipe and communicating with the PLC controller, and a manifold connected to the first pump and the second pump and coordinated with the material trough, a second liquid level sensor communicating with the PLC controller is installed in the material trough, and the dye pump is also connected to the PLC controller.

[0016] Furthermore, when the dye tank, the auxiliary agent tank and the water tank are multiple and independent of each other, the liquid replenishment control component also includes a first liquid outlet branch pipe connected to the bottom of the dye tank and equipped with a first on-off valve, a first liquid outlet transverse pipe connecting two adjacent first liquid outlet branches, a plurality of first on-off valves installed on the first liquid outlet transverse pipe, a second liquid outlet branch pipe connected to the bottom of the auxiliary agent tank and equipped with a second on-off valve, a second liquid outlet transverse pipe connecting two adjacent second liquid outlet branches, a plurality of second on-off valves installed on the second liquid outlet transverse pipe, a third liquid outlet branch pipe connected to the bottom of the water tank and equipped with a third on-off valve, a third liquid outlet transverse pipe connecting two adjacent third liquid outlet branches, and a plurality of third on-off valves installed on the third liquid outlet transverse pipe;

[0017] The first liquid outlet pipe is connected to the first liquid outlet transverse pipe and connected between two adjacent first on-off valves, and the second liquid outlet pipe is respectively connected to the second liquid outlet transverse pipe and the third liquid outlet transverse pipe and connected between two adjacent second on-off valves and the third on-off valve.

[0018] Due to the application of the above technical scheme, the present invention has the following advantages compared with the prior art: the knitted fabric cold rolling heap dyeing equipment of the present invention can realize two routing modes A and B by adopting a cold rolling component, a liquid spraying mechanism, a cloth box and a winding mechanism with a specific structure. It can be suitable for thick fabrics and thin fabrics, and can overcome the defects of the prior art of large water consumption and single specification of knitted fabrics, so that the fabric can obtain liquid evenly to improve the soaking effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the cold pad-heap dyeing equipment for knitted fabrics of the present invention;

[0020] Figure 2 It is a partial structural schematic diagram of the liquid spraying mechanism in the cold pad-heap dyeing equipment for knitted fabrics of the present invention;

[0021] Figure 3 It is a schematic structural diagram of a slurry retaining and leakage trough in the cold pad-heap dyeing equipment for knitted fabrics of the present invention;

[0022] Figure 4 It is a structural schematic diagram of the liquid spraying mechanism in the cold pad-heap dyeing equipment for knitted fabrics of the present invention;

[0023] Figure 5 It is a schematic structural diagram of a liquid replenishment control component in the cold pad-heap dyeing equipment for knitted fabrics of the present invention. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings.

[0025] like Figures 1 to 5 The knitted fabric cold rolling heap dyeing equipment shown mainly comprises a matched cold rolling component 1, a cloth box 2, a winding mechanism 3 and a liquid spraying mechanism 4.

[0026] Among them, the cold rolling assembly 1 includes a matching tightening mechanism and an impregnation mechanism, the tightening mechanism includes a support frame 12, a cloth tightening device 120 installed on the support frame 12, a multi-sided cloth guide roller 123 installed on the support frame 12, an opening roller 122 installed on the support frame 12 and located between the cloth tightening device 120 and the multi-sided cloth guide roller 123, a first transition roller 124 installed on the support frame 12 and located below the multi-sided cloth guide roller 123, and a second transition roller 125 installed on the support frame 12 and located below the first transition roller 124 (the first transition roller 124 can be used for B cloth feeding mode, and the second transition roller 125 can be used for A cloth feeding mode). The impregnation mechanism includes a housing 101, a dyeing tank 104 installed in the housing 101, an impregnation roller 105 arranged in the dyeing tank 104, a plurality of first threaded width-opening rollers 102 installed in the housing 101 and cooperating with the impregnation roller 105 and the second transition roller 125 (in this embodiment, there are two first threaded width-opening rollers 102 and they are arranged at intervals), and a first threaded width-opening roller 102 (i.e., a first threaded width-opening roller 102) arranged in one of the threaded width-opening rollers 102. Figure 1The roller group (in this embodiment, the roller group includes a passive roller 106 and an active roller 107 that can rotate in both directions and cooperate with each other) above the threaded opening roller 102 on the right side of the middle, a second threaded opening roller 110 installed in the housing 101 and located above the roller group, an open-edge blower 103 arranged between the first transition roller 124 and the second threaded opening roller 110 and cooperating therewith, an active rubber roller 109 installed on the housing 101 and located downstream of the roller group, and a transition cylinder 108 (Φ300mm~800mm, the surface of the transition cylinder 108 is engraved with horizontal lines to distribute the wet cloth on the surface without slipping and producing curling or shrinkage folds) installed on the housing 101 and cooperating with the roller group and the active rubber roller 109. In this embodiment, the tightening mechanism also includes a plurality of tension adjustment rollers 121 installed on the support frame 12 and located between the cloth tightener 120 and the opening roller 122. The active rubber roller 109 is also a roller shaft that can rotate in both directions.

[0027] At least part of the structure of the liquid spraying mechanism 4 is located above the roller group, and is used to spray the dye liquid. In this embodiment, the liquid spraying mechanism 4 includes a material trough 41 (the material trough 41 can be a separate structure; the dye trough 104 can also be directly used to save the structure), a feed pipe 42 connected to the material trough 41, a dye pump 43 installed on the feed pipe 42, a U-shaped slurry pipe 44 connected to the end of the feed pipe 42 and extending above the roller group, a slurry spraying pipe 45 connected to the U-shaped slurry spraying pipe 44, and a slurry retaining trough 46 arranged below the slurry spraying pipe 45 and cooperating with the roller group, so as to ensure uniform feeding within the width. The slurry-blocking trough 46 includes two arc-shaped side baffles 461 that are spaced apart and arranged opposite to each other, and an end plate 462 connected to the ends of the two arc-shaped side baffles 461. At this time, the two end plates 462 are spaced apart and arranged in parallel so that the two end plates 462 and the two arc-shaped side baffles 461 form a through space for the fabric to pass through, thereby avoiding turbulence or splashing of dye above the roller group.

[0028] The cloth box 2 is located on one side of the cold rolling assembly 1 and is used to place the knitted cloth to be cold rolled; the winding mechanism 3 is located on the other side of the cold rolling assembly 1 and is used to wind up the knitted cloth. In this embodiment, the winding mechanism 3 is adjustably installed on the other side of the cold rolling assembly 1, specifically: the winding mechanism 3 includes an A-shaped frame 31 slidably installed on the ground, a receiving roller 32 installed on the A-shaped frame 31, a cloth speed detection rod 33 installed on one side of the A-shaped frame 31, and a cylinder 34 connected to the A-shaped frame 31 for pulling the A-shaped frame 31 to move relative to the cold rolling assembly 1, such as a slide rail installed on the ground, and a slider matching the slide rail installed at the bottom of the A-shaped frame 31, so that the cylinder 34 can pull the A-shaped frame 31 to move when working.

[0029] The above-mentioned knitted fabric cold pad heap dyeing equipment has A cloth feeding mode and B cloth feeding mode, such as Figure 1 shown.

[0030] A cloth feeding mode: passing through the dyeing tank 104, being squeezed by the passive roller 106 and the active roller 107 to the bottom of the transition cylinder 108, entering the active rubber roller 109 and guiding the cloth downward to the receiving roller 32;

[0031] B cloth feeding method: through the first transition roller 124, the open-edge blower 103 and the second threaded open-width roller 110, from top to bottom, it is rolled by the passive roller 106 and the active roller 107, and then enters the transition cylinder 108, and then rotates upwards through the active rubber roller 109 and is brought into the winding roller 32 for packaging.

[0032] The A cloth feeding method is suitable for medium-thick fabrics, so it passes through the dyeing tank 104 and takes away a large amount of dye liquid; the B cloth feeding method passes through the two rows of spraying pipes 45 above the passive roller 106 and the active roller 107, and takes away a small amount of dye liquid, so the cloth weight is relatively light or the cloth is poorly hygroscopic, such as 20-70D nylon or polyester and other chemical fiber fabrics. Since the directions of the A and B cloth feedings when passing through the passive roller 106 and the active roller 107 are opposite, the rotation of the passive roller 106, the active roller 107 and the active rubber roller 109 are also adjustable motors in two directions (the receiving roller 32 is also bidirectional).

[0033] The knitted fabric cold rolling pile dyeing equipment also includes a liquid replenishment control component 5, so that the amount of replenished liquid is controlled by each liquid level sensor (and the dye liquid in the dye tank 104 and the spray pipe 45 is controlled at the same time). The liquid replenishment control component 5 includes at least one group of dye tanks 51 (two groups in this embodiment), at least one group of auxiliary agent tanks (two groups in this embodiment), at least one group of water tanks (two groups in this embodiment), a first liquid level sensor 50 arranged in the dye tank 51, the auxiliary agent tank 52 and the water tank 53 in a one-to-one correspondence (that is, there are multiple first liquid level sensors 50, so that each dye tank 51, the auxiliary agent tank 52 or the water tank 53 has a first liquid level sensor 50), and a PLC controller 54 communicating with the first liquid level sensor 50 (used to receive and process the liquid level signal detected by the first liquid level sensor 50, so as to realize the control of each pump; The dye pump 43 also communicates with the PLC controller 54), a first liquid outlet pipe 515 connected to the bottom of the dye tank 51, a second liquid outlet pipe 57 connected to the bottom of the auxiliary agent tank 52 and the water tank 53, a first pump 55 installed on the first liquid outlet pipe 515 and communicating with the PLC controller 54, a second pump 56 installed on the second liquid outlet pipe 57 and communicating with the PLC controller 54, and a manifold 58 connected to the first pump 55 and the second pump 56 and coordinated with the material trough 41, a second liquid level sensor 411 communicating with the PLC controller 54 is installed in the material trough 41, and the dye pump 43 is also connected to the PLC controller 54.

[0034] When the dye tank 51, the auxiliary agent tank 52 and the water tank 53 are independently multiple (such as 2 groups), the liquid replenishment control component 5 also includes a first liquid outlet branch pipe 511 connected to the bottom of the dye tank 51 and equipped with a first on-off valve 513, a first liquid outlet transverse pipe 512 connecting two adjacent first liquid outlet branches 511, and a plurality of first on-off valves 514 installed on the first liquid outlet transverse pipe 512, a second liquid outlet branch pipe 521 connected to the bottom of the auxiliary agent tank 52 and equipped with a second on-off valve 523, a second liquid outlet transverse pipe 522 connecting two adjacent second liquid outlet branches 521, and a plurality of second on-off valves 524 installed on the second liquid outlet transverse pipe 522, a third liquid outlet branch pipe 531 connected to the bottom of the water tank 53 and equipped with a third on-off valve 533, a third liquid outlet transverse pipe 532 connecting two adjacent third liquid outlet branches 531, and a plurality of third on-off valves 534 installed on the third liquid outlet transverse pipe 532. The first liquid outlet pipe 515 is connected to the first liquid outlet transverse pipe 512 and connected between two adjacent first on-off valves 514, and the second liquid outlet pipe 57 is connected to the second liquid outlet transverse pipe 522 and the third liquid outlet transverse pipe 532 respectively and connected between two adjacent second on-off valves 524 and the third on-off valve 534.

[0035] In order to ensure that the active rubber roller 109 rotates the cloth close to the receiving roller 32, the cylinder 34 generates a tensioning force on the A-frame 31, so that the active rubber roller 109 rolls the cloth to the receiving roller 32 in a close state. When the cloth is in operation, the structure of constant speed and constant tension is very important. The cloth speed detection rod 33 is a detection rod of the winding speed, which can measure the instantaneous vehicle speed and return it to the PLC controller 54 to control the frequency converter (corresponding to the active roller 107 and the active rubber roller 109), so that the active roller 107 and the active rubber roller 109 run at the specified speed, thereby ensuring constant speed and constant tension.

[0036] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A knitted fabric cold pad heap dyeing equipment, characterized in that: It includes: A cold rolling assembly (1), the cold rolling assembly (1) comprising a matching tightening mechanism and an impregnation mechanism, the tightening mechanism comprising at least a support frame (12), a cloth tightening device (120) mounted on the support frame (12), a multi-faceted cloth guide roller (123) mounted on the support frame (12), an opening roller (122) mounted on the support frame (12) and located between the cloth tightening device (120) and the multi-faceted cloth guide roller (123), a first transition roller (124) mounted on the support frame (12) and located below the multi-faceted cloth guide roller (123), and a second transition roller (125) mounted on the support frame (12) and located below the first transition roller (124); the impregnation mechanism comprising at least a shell (101), a dyeing tank (104) mounted in the shell (101), and an impregnation roller arranged in the dyeing tank (104). (105), a plurality of first threaded width-opening rollers (102) installed in the shell (101) and cooperating with the impregnation roller (105) and the second transition roller (125), a roller group arranged above one of the threaded width-opening rollers (102), a second threaded width-opening roller (110) installed in the shell (101) and located above the roller group, an edge-opening blower (103) arranged between the first transition roller (124) and the second threaded width-opening roller (110) and cooperating therewith, an active rubber roller (109) installed on the shell (101) and located downstream of the roller group, and a transition cylinder (108) installed on the shell (101) and cooperating with the roller group and the active rubber roller (109); the roller group includes a passive roller (106) and an active roller (107) which can rotate in both directions and cooperate with each other; A liquid spraying mechanism (4), wherein at least a part of the structure of the liquid spraying mechanism (4) is located above the roller group and is used for spraying dye liquid; A cloth box (2), the cloth box (2) being located on one side of the cold rolling component (1) and being used for placing knitted cloth to be cold rolled; A winding mechanism (3), the winding mechanism (3) is located on the other side of the cold rolling component (1) and is used for winding the knitted fabric.

2. The knitted fabric cold pad heap dyeing equipment according to claim 1, characterized in that: The tightening mechanism further comprises a plurality of tension adjustment rollers (121) which are mounted on the support frame (12) and are located between the cloth tightening device (120) and the width opening roller (122).

3. The knitted fabric cold pad heap dyeing equipment according to claim 1, characterized in that: The active rubber roller (109) is a roller shaft that can rotate in both directions.

4. The knitted fabric cold pad heap dyeing equipment according to claim 1, characterized in that: The winding mechanism (3) is adjustably mounted on the other side of the cold rolling assembly (1), and comprises an A-shaped frame (31) slidably mounted on the ground, a receiving roller (32) mounted on the A-shaped frame (31), a cloth speed detection rod (33) mounted on one side of the A-shaped frame (31), and a cylinder (34) connected to the A-shaped frame (31) for pulling the A-shaped frame (31) to move relative to the cold rolling assembly (1).

5. The knitted fabric cold pad heap dyeing equipment according to claim 1, characterized in that: The liquid spraying mechanism (4) comprises a material trough (41), a material delivery pipe (42) connected to the material trough (41), a dye pump (43) installed on the material delivery pipe (42), a U-shaped slurry delivery pipe (44) connected to the end of the material delivery pipe (42) and extending to the top of the roller group, a slurry spraying pipe (45) connected to the U-shaped slurry delivery pipe (44), and a slurry retaining leakage groove (46) arranged below the slurry spraying pipe (45) and cooperating with the roller group.

6. The knitted fabric cold pad heap dyeing equipment according to claim 5, characterized in that: The slurry blocking trough (46) comprises two arc-shaped side baffles (461) spaced apart and arranged opposite to each other, and an end plate (462) connected to the ends of the two arc-shaped side baffles (461).

7. The knitted fabric cold pad heap dyeing equipment according to claim 5, characterized in that: It also includes a liquid replenishment control component (5), the liquid replenishment control component (5) including at least one group of dye tanks (51), at least one group of auxiliary agent tanks (52), at least one group of water tanks (53), first liquid level sensors (50) arranged in the dye tanks (51), the auxiliary agent tanks (52) and the water tanks (53) in a one-to-one correspondence, a PLC controller (54) communicating with the first liquid level sensor (50), a first liquid outlet pipe (515) connected to the bottom of the dye tank (51), a second liquid outlet pipe (516) connected to the bottom of the auxiliary agent tank (52) and the water tank (53), and a control unit (517) configured to control the liquid level of the dye tank (51). 7), a first pump (55) installed on the first liquid outlet pipe (515) and communicating with the PLC controller (54), a second pump (56) installed on the second liquid outlet pipe (57) and communicating with the PLC controller (54), and a manifold (58) connected to the first pump (55) and the second pump (56) and matched with the material trough (41), a second liquid level sensor (411) communicating with the PLC controller (54) is installed in the material trough (41), and the dye pump (43) is also connected to the PLC controller (54).

8. The cold pad heap dyeing equipment for knitted fabrics according to claim 7, characterized in that: When the dye tank (51), the auxiliary agent tank (52) and the water tank (53) are multiple and independent of each other, the liquid replenishment control component (5) further comprises a first liquid outlet branch pipe (511) connected to the bottom of the dye tank (51) and equipped with a first on-off valve (513), a first liquid outlet transverse pipe (512) connected to two adjacent first liquid outlet branch pipes (511), a plurality of first on-off valves (514) installed on the first liquid outlet transverse pipe (512), and a second on-off valve (523) connected to the bottom of the auxiliary agent tank (52). ), a second liquid outlet branch pipe (521) connecting two adjacent second liquid outlet branch pipes (521), a plurality of second on-off valves (524) installed on the second liquid outlet transverse pipe (522), a third liquid outlet branch pipe (531) connected to the bottom of the water tank (53) and equipped with a third on-off valve (533), a third liquid outlet transverse pipe (532) connecting two adjacent third liquid outlet branch pipes (531), and a plurality of third on-off valves (534) installed on the third liquid outlet transverse pipe (532); The first liquid outlet pipe (515) is connected to the first liquid outlet transverse pipe (512) and is connected between two adjacent first on-off valves (514); the second liquid outlet pipe (57) is respectively connected to the second liquid outlet transverse pipe (522) and the third liquid outlet transverse pipe (532) and is connected between two adjacent second on-off valves (524) and the third on-off valve (534).

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