Electromagnetic pilot valve for cryogenic fluid

Abstract

Electromagnetic pilot valves for cryogenic fluids are disclosed. An example valve includes a body defining an inlet side and an outlet side. The valve includes a coil assembly coupled to the body. The valve includes a poppet valve configured to translate between a closed position and an open position. The poppet valve defines a guide hole configured to fluidly connect the chamber and the outlet side. The valve includes a plunger assembly positioned in the chamber. The plunger assembly includes a first plunger positioned such that the coil assembly is configured to translate the first plunger. The plunger assembly includes a second plunger slidably coupled to the first plunger. The second plunger is configured to close the guide hole in a second extended position and to open the guide hole in a partially retracted position and a second retracted position.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to solenoid valves, and more particularly to solenoid pilots for cryogenic fluids. BACKGROUND

[0002] Cryogenic control systems are configured to regulate fluids in cryogenic cylinders or tanks. Cryogenic cylinders generally contain a combination of liquid and gas at cryogenic temperatures (e.g., temperatures below -150 degrees Celsius (-238 degrees Fahrenheit)). For example, a cryogenic tank can contain a liquid (e.g., liquefied natural gas, liquid hydrogen) and a gas (e.g., natural gas, hydrogen) in a headspace above the liquid.

[0003] Typically, valves are used to regulate the flow of fluid from a cryogenic tank. In some examples, the cryogenic valve is a solenoid valve. Solenoid valves can include a solenoid coil mounted to a valve body. Some solenoid valves are normally open valves, where energizing the solenoid coil closes the valve and de-energizing the solenoid coil opens the valve. Other solenoid valves are normally closed valves, where energizing the solenoid coil opens the valve and de-energizing the solenoid coil closes the valve. Some normally closed valves for cryogenic fluids have difficulty forming a tight seal connection in the closed position, unintentionally allowing cryogenic fluid to flow from the cryogenic tank in the closed position. SUMMARY

[0004] An example solenoid pilot valve for cryogenic fluids disclosed herein includes a valve body. The valve body includes a first seat and defines a conduit having an inlet side and an outlet side. The solenoid pilot valve includes a coil assembly coupled to the valve body. The solenoid pilot valve includes a poppet configured to translate between a closed position in which the poppet sealingly engages the first seat to fluidly disconnect the inlet side from the outlet side and an open position in which the poppet disengages from the first seat to fluidly connect the inlet side and the outlet side. The poppet, the valve body, and the coil assembly define a chamber. The poppet defines a pilot bore configured to fluidly connect the chamber and the outlet side. The poppet includes a second seat proximate the pilot bore. The solenoid pilot valve includes a plunger assembly positioned in the chamber. The plunger assembly includes a first plunger positioned such that the coil assembly is configured to translate the first plunger between a first extended position and a first retracted position. The plunger assembly includes a second plunger slidably coupled to the first plunger and extending toward the poppet. The second plunger is configured to translate between a second extended position, a partially retracted position, and a second retracted position. The second plunger is configured to sealingly engage the second seat to close the pilot bore in the second extended position and configured to disengage from the second seat to open the pilot bore in the partially retracted position and the second retracted position. BRIEF DESCRIPTION OF DRAWINGS

[0005] Figure 1 is a cross-sectional view of an example electromagnetic directional valve for cryogenic fluids in accordance with the teachings herein.

[0006] Figure 2 is an electromagnetic directional valve in a closed state Figure 1 is a detailed cross-sectional view of the poppet assembly and the poppet of the electromagnetic directional valve of

[0007] Figure 3 is a detailed cross-sectional view of the poppet of Figure 2

[0008] Figure 4 illustrates Figure 2 Figure 1

[0009] Figure 5 is a detailed cross-sectional view of the upper poppet of the poppet assembly shown in Figure 2

[0010] Figure 6 is a detailed cross-sectional view of the lower poppet of the poppet assembly shown in Figure 2

[0011] Figure 7 is a perspective view of the poppet assembly of Figure 2 Figure 6

[0012] Figure 8 is a detailed cross-sectional view of the poppet assembly of Figure 1 Figure 2

[0013] Figure 9 Figure 1 Figure 2

[0014] Figure 10 is a cross-sectional view of the electromagnetic poppet valve of Figure 1

[0015] Figure 11 Figure 1

[0016] Figure 12 is a cross-sectional view of the electromagnetic poppet valve of Figure 1

[0017] Figure 13 ​​​​​​​​​​​​​​​​is a cross-sectional view of another example electromagnetic directional valve for cryogenic fluids according to the teachings herein.

[0018] Figure 14 is the electromagnetic directional valve of Figure 13 is a cross-sectional view of a plunger assembly and poppet valve of the electromagnetic directional valve of DETAILED DESCRIPTION

[0019] The following description describes, illustrates, and exemplifies one or more embodiments of the present invention according to the principles of the invention. The description is not meant to limit the present invention to the embodiments described, but is intended to explain and teach the principles of the invention so that others can understand how to make and use the invention. The present specification is therefore to be construed in view of the principles of the invention.

[0020] The scope of the invention is to be accorded the broadest interpretation so as to encompass all such embodiments as can now or later fall within the scope of the appended claims, either literally or under the doctrine of equivalents. The description describes illustrative embodiments, which are not to be taken in a limiting sense but are understood to be exemplary and illustrative only. Features described in the specification that are not essential to the principles of the invention can be omitted in implementations of the invention.

[0021] It is noted that, in the description and drawings, like or substantially similar elements can be labeled with the same reference numerals. However, these elements can sometimes be labeled with different numbers, for example, where such labeling facilitates a clearer description. In addition, the drawings set forth herein are not necessarily drawn to scale, and in some instances the dimensions can be exaggerated to more clearly depict certain features. Such labeling and drawing practices do not necessarily imply a substantial substantive significance in all instances.

[0022] Some features can be described using relative terms such as top, bottom, vertical, right, left, etc. It should be appreciated that such relative terms are used only with respect to the drawings. These relative terms are not intended to limit the disclosed embodiments.

[0023] Examples of electromagnetic directional valves disclosed herein include a valve body, a coil assembly coupled to the valve body, a poppet valve, and a plunger assembly having a guide bore. The coil assembly is configured to be energized and / or de-energized to cause movement of the plunger assembly, which in turn is configured to cause movement of the poppet valve. The poppet valve is configured to translate between a closed position that restricts flow of a cryogenic fluid and an open position that allows flow of the cryogenic fluid. The electromagnetic directional valve also includes one or more springs to bias the poppet valve toward the closed position.

[0024] The solenoid valve is configured to form a tight sealing connection in the closed state to prevent the cryogenic fluid from inadvertently leaking through the solenoid valve. For example, one spring of the solenoid valve has a relatively large closing force and is arranged to ensure that the plunger assembly and poppet form a sealing connection when the solenoid valve is transitioned from the open state to the closed state. To transition to its open state, the solenoid valve overcomes the closing force of the spring.

[0025] To facilitate the solenoid valve overcoming the closing force of the spring, the plunger assembly is a multi-plunger assembly that includes an upper plunger partially nested within a lower plunger. For example, the coil assembly, when energized, pulls the upper plunger upward along with the lower plunger. When the lower plunger is pulled upward, it disengages from a poppet seat of the poppet to fluidly connect an outlet side of the valve body to a pressure chamber in which the plunger assembly is positioned. The pressure within the pressure chamber, in turn, equalizes with the pressure of the outlet side pressure, which enables the lower plunger to slide upward relative to the upper plunger and enables the poppet to slide upward and disengage from the seat to open the solenoid valve. Additionally, the upper plunger of the plunger assembly has a relatively short stroke length to further facilitate the solenoid valve overcoming the closing force of the spring. For example, the stroke length of a solenoid valve for liquefied natural gas (LNG) is approximately 0.80 millimeters (0.031 inch), and the stroke length of a solenoid valve for liquid hydrogen (LH2) is approximately 0.88 millimeters (0.035 inch).

[0026] That is, examples of the solenoid valve disclosed herein include a spring having a relatively large closing force to ensure that the plunger forms a tight sealing connection with the seat in the closed position. The solenoid valve includes a multi-plunger assembly and incorporates a relatively short stroke length of the upper plunger to enable the solenoid valve to overcome the closing force of the spring and, in turn, transition to the open state.

[0027] Additionally, when the coil assembly is de-energized, the spring pushes the poppet and the upper and lower plungers of the plunger assembly downward with a relatively large closing force to ensure that (1) the poppet forms a tight seal with the seat and (2) the lower plunger forms a tight seal with the poppet seat in the closed state. In examples disclosed herein, the poppet can also include a relatively small O-ring that is capable of forming a tight seal with the seat at cryogenic temperatures without deforming. Additionally or alternatively, the poppet seat can be at least partially formed of plastic to ensure a tight seal between the lower plunger and the poppet seat in the closed state. Furthermore, in some such examples, the poppet seat is an insert that can be removed and replaced after a long period of use.

[0028] Turning to the figures, Figure 1 An example embodiment of a solenoid valve 100 (also referred to as “valve” and “pilot valve”) is illustrated. The valve 100 is configured to control the flow of a cryogenic fluid, such as liquefied natural gas (LNG). The illustrated example of the valve 100 includes a body 200 (also referred to as “valve body”), a coil assembly 300, a poppet 400, and a plunger assembly 500.

[0029] The body 200 of the valve 100 includes a main body 210 that defines a conduit 215, an inlet port 220, and an outlet port 225. The conduit 215 extends between the inlet port 220 and the outlet port 225 such that the outlet port 225 is in fluid communication with the inlet port 220 to enable cryogenic fluid (e.g., LNG) to flow from the inlet port 220 to the outlet port 225. In some examples, the inlet port 220 and the outlet port 225 are threaded, standard-sized hydraulic ports configured to receive a fluid fitting. The conduit 215 includes an inlet side 230 proximate to the inlet port 220 and an outlet side 235 proximate to the outlet port 225. The inlet side 230 and the outlet side 235 are separated by a valve seat 240. The main body 210 includes the valve seat 240 (also referred to as a "first seat" or a "first valve seat") that is positioned along the conduit 215 between the inlet port 220 and the outlet port 225. In the illustrated example, the valve seat 240 is angled. As disclosed in greater detail below, the valve seat 240 is configured to sealingly engage and disengage from a poppet 400. When the valve seat 240 sealingly receives the poppet 400, the outlet port 225 is fluidly disconnected from the inlet port 220 to prevent cryogenic fluid from flowing through the conduit 215. When the poppet 400 disengages from the valve seat 240, the outlet port 225 is fluidly connected to the inlet port 220 to allow cryogenic fluid to flow through the conduit 215.

[0030] The body 200 also includes a barrel 250 that is coupled to and extends between the main body 210 and the coil assembly 300. For example, the barrel 250 is threadably coupled to the main body 210. The barrel 250 includes a lower barrel body 255 and an upper barrel body 260 that are integrally formed together. The lower barrel body 255 is coupled to the main body 210 (e.g., threadably, via a press fit, etc.). For example, a portion of the lower barrel body 255 extends into and is received by the main body 210 to couple to the main body 210. The upper barrel body 260 is coupled to the coil assembly 300 (e.g., such as threadably, via a press fit, etc.). For example, a portion of the upper barrel body 260 extends into and is received by the housing 305 of the coil assembly 300 to couple to the coil assembly 300.

[0031] That is, the coil assembly 300 is coupled to the barrel 250 of the body 200. In the illustrated example, the coil assembly 300 includes a housing 305 that includes a coil housing 310 and a wiring housing 315. The coil assembly 300 also includes a coil 320 that is housed in the coil housing 310 and is configured to operate as an electromagnet. The wiring housing 315 houses wiring that is operably connected to the coil 320. For example, control wiring transmits a control signal to energize or de-energize the coil 320.

[0032] Coil housing 310 is a hollow cylinder that defines a bore 340 extending along its longitudinal axis. Coil assembly 300 includes a plug 325 that is at least partially positioned within bore 340 toward its upper end. Plug 325 is formed of a magnetic material. Further, plug 325 is positioned in bore 340 of coil housing 310 and formed of a material having magnetic properties such that plug 325 generates a magnetic force to pull plunger 600 upward when coil 320 is energized. Coil assembly 300 further includes a cap 330 and a seal 335. Cap 330 covers and closes an upper opening of bore 340 of coil housing 310. In the illustrated example, cap 330 is threadably coupled to plug 325 and sealingly engages housing 305 of coil assembly 300 via threads. Seal 335 is configured to engage cap 330 and housing 305 and form a sealed connection between cap 330 and housing 305.

[0033] Additionally, barrel 250 of body 200 is coupled to housing 305 of coil assembly 300. In the illustrated example, valve 100 includes a washer 910 positioned between barrel 250 and housing 305 of coil assembly 300. In the illustrated example, upper barrel 260 of barrel 250 extends at least into bore 340 of coil housing 310 through a lower opening of the bore. Upper barrel 260 can be securely positioned relative to coil assembly 300 by being press fit into bore 340 of coil housing 310. Further, an upper end of upper barrel 260 engages a lower end of plug 325 within bore 340 of coil housing 310. In some examples, upper barrel 260 of barrel 250 is fixedly coupled to the lower end of plug 325 (e.g., via welding).

[0034] Poppet valve 400 of valve 100 is partially housed within lower barrel 255 and extends downward beyond barrel 250. For example, poppet valve 400 extends downward below barrel 250 through a central aperture in lower barrel 255 of barrel 250. An upper portion of poppet valve 400 is housed within lower barrel 255, and a lower portion of poppet valve 400 extends from barrel 250. As disclosed in greater detail below, poppet valve 400 is configured to translate between a closed position (as shown in FIGS. 1-11) and an open position (as shown in FIGS. 12-14). In the closed position, poppet valve 400 sealingly engages valve seat 240 to fluidly disconnect inlet side 230 from outlet side 235 to prevent cryogenic fluid flow through conduit 215 of valve 100. In the open position, poppet valve 400 disengages from valve seat 240 to fluidly connect inlet side 230 of body 200 with outlet side 235 to allow cryogenic fluid flow through conduit 215 of valve 100. Figure 1 and 10 to 11) and an open position (as shown in FIGS. 12-14). In the closed position, poppet valve 400 sealingly engages valve seat 240 to fluidly disconnect inlet side 230 from outlet side 235 to prevent cryogenic fluid flow through conduit 215 of valve 100. In the open position, poppet valve 400 disengages from valve seat 240 to fluidly connect inlet side 230 of body 200 with outlet side 235 to allow cryogenic fluid flow through conduit 215 of valve 100. Figure 12

[0035] ​Additionally, the lift valve 400, body 200, and / or coil assembly 300 define a chamber 265 (also referred to as a "pressure chamber"). For example, chamber 265 is at least partially defined by the lift valve 400 and cylinder 250 of body 200. Furthermore, chamber 265 is also defined by the plug 325 of coil assembly 300. In other embodiments, cylinder 250 may be shaped and positioned relative to coil assembly 300 such that cylinder 250 and lift valve 400 are combined to form chamber 265. Furthermore, a gap formed between lift valve 400 and plunger 700 allows the various portions of chamber 265 to be fluidly connected to each other. For example, a gap (e.g., a radial gap) formed between lift valve 400 and plunger 700 fluidly connects upper portion 266 and middle portion 267 of chamber 265, and another gap (e.g., a radial gap) between lift valve 400 and plunger 700 fluidly connects middle portion 267 and lower portion 268 of chamber 265. The lift valve 400 is also coaxially aligned with and configured to translate relative to the plungers 600, 700 and coil 320. Figure 2 The positioning of the lift valve 400 relative to the plungers 600 and 700 of the plunger assembly 500 is further described.

[0036] Figure 3 The lift valve 400 is further described. In the illustrated example, the lift valve 400 includes an upper body 410, a lower body 420, and a head 430 integrally formed together. The upper body 410 (also referred to as the "upper lift valve body") is located at the upper end of the lift valve 400, and the head 430 (also referred to as the "lift valve head") is located at the opposite lower end. The lower body 420 extends between and connects to the upper body 410 and the head 430. [Go to...] Figure 4 The lower body 420 includes an outer flat or concave surface 465 configured to slidably engage the inner flat or concave surface 935 of the gasket 930. The gasket 930 is securely positioned within the body 200 of the valve 100 and configured to slidably receive the lift valve 400 in a keyway manner to prevent rotation of the lift valve 400 about the longitudinal axis of the lift valve 400 and / or the plunger assembly 500. For example, as Figure 1 As shown, the gasket 930 is securely positioned at the end of the lower cylinder 255 and the flange 245 defined by the body 210.

[0037] Return to Figure 3 The head 430 includes a seal 435 (e.g., an O-ring seal) configured to sealably engage the valve seat 240 when the lift valve 400 is in its closed position. When the coil 320 is de-energized, as... Figure 1As shown in the middle, the poppet valve 400 is configured to rest in a closed position at which the seal 435 sealingly engages the valve seat 240 to prevent cryogenic fluid flow through the conduit 215. The seal 435 is sized and shaped to prevent deformation at cryogenic temperatures, which otherwise can lead to a non-sealing connection with the valve seat 240 over time in the closed position.

[0038] The upper body 410 is hollow and defines a cavity 415 that is configured to slidably receive a lower portion of the plunger 700. The poppet valve 400 also includes a cap 440 coupled to the upper body 410 at its upper end. The cap 440 is positioned relative to the plunger 700 to prevent the plunger 700 from tilting from the longitudinal axis of the poppet valve 400 and / or the plunger assembly 500 as the plunger 700 slides through the cavity 415. In the illustrated example, the cap 440 includes an annular groove configured to receive an upper end of the spring 820.

[0039] The upper body 410 and / or the lower body 420 of the poppet valve 400 also define a bore 425 extending from a lower end of the cavity 415. The bore 425 is configured to securely receive a seat 450 of the poppet valve 400, e.g., via a press fit. In the illustrated example, the seat 450 (also referred to as a "poppet seat," a "second seat," or a "second valve seat") is an insert and includes a seal 455 and a retainer 460. The seat 450 is an insert so that it can be removed from the bore 425 for maintenance and / or replacement. That is, the seat 450 is a replaceable insert. The seal 455 has an inverted T-shaped cross-section and is configured to be engaged by the plunger 700, e.g., the ball 750 of the plunger 700, when the plunger 700 is in its extended position. The retainer 460 is positioned circumferentially around the seal 455 and engages the seal 455. Further, the retainer 460 is configured to engage the upper body 410 and / or the lower body 420 of the poppet valve 400 when the seat 450 is press fit into place within the bore 425. The seal 455 and the retainer 460 are arranged so that the seat 450 has one or more sealing surfaces. For example, the seat 450 has a circumferential sealing surface, an upwardly facing nose, and / or a bottom sealing surface.

[0040] As Figure 3 As illustrated in the middle, the poppet valve 400 defines a guide bore 470. The guide bore 470 extends from the head 430 through the lower body 420 and to the cavity 415 defined by the upper body 410. The poppet valve 400 is positioned so that an upper end of the guide bore 470 is fluidly connected to the chamber 265 via the cavity 415 and a lower end of the guide bore 470 is fluidly connected to the outlet side 235 of the body 200 via the conduit 215. Additionally, the seat 450 is positioned at the upper end of the guide bore 470 so that the seat 450 is adjacent to the guide bore 470.

[0041] As disclosed in greater detail below, the guide hole 470 enables the outlet side 235 of the body 200 to be fluidly connected to the chamber 265 when the plunger 700 is disengaged from the seat 450. In contrast, the guide hole 470 is closed when the plunger 700 is in sealing engagement with the seat 450 to fluidly disconnect the outlet side 235 from the chamber 265. The plunger 700 engages or disengages the seat to close or open the guide hole 470, respectively. Fluid pressure within the chamber 265 is in turn controlled in a manner that facilitates the poppet valve 400 (1) transitioning between its closed and open positions and (2) ensuring a tight seal with the valve seat 240 in its closed position.

[0042] The poppet valve 400 of the illustrated example includes a peripheral groove 405 that is configured to receive a bleeder seal 920. Returning to Figure 1 , the bleeder seal 920 separates the chamber 265 from the inlet side 230 of the conduit 215. That is, the bleeder seal 920 bounds the lower end of the chamber 265. The bleeder seal 920 is configured to engage the poppet valve 400 and the body 200. In particular, the bleeder seal 920 is configured to engage the poppet valve 400 and the barrel 250 of the body 200. The bleeder seal 920 is positioned between the inlet side 230 of the conduit 215 and the chamber 265 to form an orifice that allows fluid to flow (e.g., "bleed") between the inlet side 230 and the chamber 265 at a relatively slow rate. For example, the bleeder seal 920 can be sized and arranged to allow fluid to flow between the inlet side 230 and the chamber 265 at a controlled, predetermined rate. Also and as disclosed in greater detail below, the bleeder seal 920 is configured to allow fluid pressure to slowly equalize between the inlet side 230 and the chamber 265 over time. For example, the bleeder seal 920 is positioned between the poppet valve 400 and the body 200 to cause the chamber pressure within the chamber 265 to slowly equalize with the chamber pressure of the inlet side 230 over time when the poppet valve 400 is in its closed position.

[0043] As shown in Figure 1 , the solenoid 150 of the valve 100 is formed from a coil assembly 300 and a plunger assembly 500. The plunger assembly 500 is positioned in the chamber 265 and includes a plunger 600 (also referred to as an "upper plunger" or a "first plunger") and a plunger 700 (also referred to as a "lower plunger" or a "second plunger"). The plunger assembly 500 also includes a pin 800 that is configured to slidably couple the plunger 700 to the plunger 600.

[0044] The plunger 600 extends at least partially into the bore 340 of the coil housing 310 through the lower opening of the bore. In the illustrated example, the plunger 600 is also at least partially housed within the upper barrel 260 of the barrel 250. The plunger 600 is coaxially aligned with the coil 320 of the coil assembly 300. The plunger 600 is configured to translate between an extended position (also referred to as a "first extended position") and a retracted position (also referred to as a "first retracted position"). As disclosed in further detail below, the coil 320 is configured to control the positioning of the plunger 600. More specifically, the plunger 600 is positioned relative to the coil assembly 300 such that the coil 320 is configured to translate the plunger 600 between its extended and retracted positions.

[0045] Turning to Figure 5 , the plunger 600 of the illustrated example includes an upper end 610 and an opposite lower end 615. The plunger 600 includes an upper body 620 adjacent the upper end 610 and a lower body 625 adjacent the lower end 615. The upper body 620 and the lower body 625 are integrally formed together. The upper body 620 has an outer diameter that is greater than an outer diameter of the lower body 625. The upper body 620 is sized to be securely and slidably received by the upper barrel 260 and / or the coil housing 310. The lower body 625 is sized to be securely and slidably received by the plunger 700 (e.g., by the cavity 705 of the plunger 700). Figure 6 The plunger 600 defines a through bore 630 that extends its length between the upper end 610 and the lower end 615. Further, the through bore 630 extends along a longitudinal axis of the plunger 600. As shown in Figures 1 to 2 , the spring 810 of the valve 100 is configured to extend through the through bore 630.

[0046] Returning to Figure 5 , the plunger 600 defines opposing slots 640 (also referred to as "vertical slots") that extend transversely (e.g., perpendicularly) to the through bore 630. Each slot 640 extends vertically along the lower body 625 of the plunger 600. For example, each slot 640 includes a lower end 645 and an opposite upper end 650. As disclosed in further detail below, the pin 800 is configured to extend through the slots 640 to couple the plunger 600 and the plunger 700 together. The slots are shaped to enable the plunger 700 to slide relative to the plunger 600 while remaining coupled together. For example, the pin 800 is configured to slide from the lower end 645 to the upper end 650 of the slots 640 to allow the plunger 700 to translate the plunger 600 to its retracted position. Conversely, the pin 800 is configured to slide from the upper end 650 to the lower end 645 of the slots 640 as the plunger 700 is moved downward to allow the plunger 700 to translate relative to the plunger 600 to its extended position.

[0047] Returning to Figures 1 to 2plunger 700 extends toward the poppet valve 400. The plunger 700 extends at least partially into the bore 340 of the coil housing 310 through the lower opening of the bore. The plunger 700 is also housed within the barrel 250. The plunger 700 is coaxially aligned with the plunger 600 and the coil 320. The plunger 700 is configured to translate between its extended position (also referred to as a "second extended position"), its partially retracted position, and its fully retracted position (also referred to as a "second retracted position").

[0048] Turning to Figure 6 The plunger 700 includes an upper body 710 proximate its upper end and a lower body 720 proximate its lower end. The upper body 710 and the lower body 720 are integrally formed together. The upper body 710 has an outer diameter that is greater than an outer diameter of the lower body 720. The upper body 710 is sized to be securely and slidably received by the upper barrel body 260 and / or the coil housing 310. The lower body 720 is sized to be securely and slidably received by the cavity 415 of the poppet valve 400 and / or the cap 440.

[0049] The plunger 700 includes a ball 750 at its lower end. In the illustrated example, the ball 750 is securely received (e.g., via a press fit) by a cavity 730 positioned along the lower end of the plunger 700. The ball 750 is configured to sealingly engage the seat 450 in the extended position of the plunger 700 and configured to disengage from the seat 450 in the partially retracted position and the fully retracted position of the plunger 700. In some examples, the ball 750 is formed of a metallic material and the seal 455 of the seat 450 is formed of a plastic material to facilitate the plunger 700 and the seat 450 consistently forming a sealed connection. Additionally, when engaging the seat 450, the ball 750 sealingly closes the guide bore 470 to fluidly disconnect the chamber 265 from the outlet side 235 of the valve 100. When disengaging from the seat 450, the ball 750 opens the guide bore 470 to fluidly connect the chamber 265 from the outlet side 235 of the valve 100.

[0050] The plunger 700 also defines a cavity 705 (also referred to as a "first plunger cavity") extending from its upper end toward its lower end. For example, the cavity 705 extends vertically the length of the upper body 710 and a portion of the length of the lower body 720. The cavity 705 is configured to slidably receive the lower body 625 of the plunger 600 to enable the plungers 600, 700 to be slidably coupled together. Additionally, as Figure 2 and 8 As most clearly shown in FIGS. 9-9, the cavity 705 is also configured to house a spring support 770 of the plunger 700. The spring support 770 includes a foot 775 at its lower end and a seat 780 at its opposite upper end. The foot 775 is configured to engage and support an end of the spring 830 and the seat 780 is configured to engage and support an end of the spring 810. Additionally, the spring support 770 defines a through hole 785 through which the pin 800 extends.

[0051] Returning to Figure 6 , the plunger 700 also defines opposing holes 725 transverse (e.g., perpendicular) to the cavity 705. As disclosed in greater detail below, each hole 725 is configured to receive a respective end of the pin 800 to slidably couple the plungers 600, 700 together. In addition, the plunger 700 includes a sleeve 740 configured to securely hold the pin 800 within the holes 725 and the slots 640. In the illustrated example, the sleeve 740 extends circumferentially around and engages an outer surface of the lower body 720. The sleeve 740 extends vertically from a lower end of the plunger 700 to overhang the holes 725 to cover the holes 725 in a manner that securely holds the pin 800 within the holes 725. The sleeve 740 is also positioned relative to the cover 440 of the poppet valve 400 to form a gap that fluidly connects the upper portion 266 and the middle portion 267 of the chamber 265 together.

[0052] As shown in Figures 7 to 9 , the plunger 700 is positioned relative to the plunger 600 such that the holes 725 are aligned with the slots 640. The pin extends into each hole 725 of the plunger 700, through each slot 640 of the plunger 600, and through the through-hole 785 of the spring support 770 to securely couple the plungers 600, 700 together. More specifically, the plunger 700 is slidably coupled to the plunger 600 via the pin 800. The plunger 700 is configured to translate with the plunger 600 when the plunger 700 transitions from its extended position to its partially retracted position, and the plunger 700 is configured to slide relative to the plunger 600 when the plunger 700 transitions from its partially retracted position to its fully retracted position. Figures 7 to 8 The plunger assembly 500 is depicted with the plunger 700 in its extended position and / or partially retracted position with the pin 800 engaging the lower end 645 of the slots 640 of the plunger 600. Figure 9 The plunger assembly 500 is depicted with the plunger 700 in its retracted position with the pin 800 engaging the upper end 650 of the slots 640. The pin 800 is enabled to vertically slide within the slots 640 between the lower end 645 and the upper end 650 to allow the plunger 700 to slide relative to the plunger 600.

[0053] Returning to Figure 1 , the valve 100 includes one or more springs configured to bias the poppet valve 400 and / or the plunger 700 in a particular direction. For example, the valve 100 includes a spring 810 (also referred to as a “first spring”), a spring 820 (also referred to as a “second spring”), and a spring 830 (also referred to as a “third spring”).

[0054] Spring 810 extends through through hole 630 of plunger 600. Furthermore, spring 810 is located at plug 325 of coil assembly 300 and spring support 770 of plunger 700. Figure 2 The spring 810 extends between and engages with the seat 780. The spring 810 is arranged in such a way that it biases the plunger 700 toward its extended position to close the guide hole 470 and / or biases the lift valve 400 toward its closed position to close the conduit 215. For example, as disclosed in more detail below, the spring 810 is configured to push the plunger 700 from its fully retracted position to its extended position to sealably engage the seat 450 and / or push the lift valve 400 from its open position to its closed position to sealably engage the valve seat 240.

[0055] Spring 820 is positioned within cavity 415 of lift valve 400. Furthermore, spring 820 extends between and engages with cap 440 of lift valve 400 and foot 745 of plunger 700. Spring 820 is arranged in such a way that (1) when valve 100 is in its closed state, it downwardly biases plunger 700 to hold it in its extended position; (2) when valve 100 is in its intermediate state, it allows lift valve 400 to open; and / or (3) when plunger 700 is in its fully retracted position, it upwardly biases lift valve 400 to hold lift valve 400 in its open position when valve 100 is in its closed state. Furthermore, foot 745 is positioned within cavity 415 and relative to upper body 410 of lift valve 400 to form a gap that fluidly connects intermediate portion 267 and lower portion 268 of chamber 265.

[0056] Spring 830 is located at the lower end 615 of plunger 600 and spring support 770 of plunger 700. Figure 2 The spring 830 extends between and engages with the foot 775 of the plunger 600. The spring 830 is arranged in such a way that when the plunger 700 is in its extended position, it biases the plunger 600 upward toward its extended position. The spring 830 holds the plunger 600 in its extended position to prevent the plunger 600 from translating downward when the coil 320 is de-energized.

[0057] Figures 10 to 12 Valve 100 is depicted in various operating states. Specifically, Figure 10 Valve 100 is depicted in the closed state. Figure 11 Valve 100 is depicted in the intermediate state, and Figure 12Valve 100 is depicted in an open state. Coil 320 of coil assembly 300 is configured to transition between a de-energized state and an energized state to cause valve 100 to transition between its closed state and open state, respectively. That is, valve 100 is configured to transition from its closed state to its open state in response to coil 320 of coil assembly 300 transitioning to its energized state. Conversely, valve 100 is configured to transition from its open state to its closed state in response to coil 320 of coil assembly 300 transitioning to its de-energized state.

[0058] Turning to Figure 10 Valve 100 is in its closed state, with coil 320 of coil assembly 300 in its de- energized state. When coil 320 is de-energized, coil 320 does not emit a magnetic field with a force (e.g., about 15 N) that pulls plunger 600 upward. Thus, the biasing force of spring 810 pushes plunger 700 to its extended position, and in turn, pushes poppet 400 to rest in its closed position. That is, when valve 100 is in its closed state, poppet 400 is in its closed position in which it sealingly engages with valve seat 240 to fluidly disconnect inlet side 230 from outlet side 235 to prevent cryogenic fluid from flowing through conduit 215. Additionally, plunger 700 is in its extended position in which ball 750 of plunger 700 sealingly engages with seat 450 to close the through-hole to fluidly disconnect chamber 265 from outlet side 235. Moreover, when poppet 400 and plunger 700 are in their closed position and extended position, respectively, the biasing force of spring 830 pushes plunger 600 to slide upward relative to plunger 700 until pin 800 contacts lower end 645 of slot 640, at which point plunger 600 is in its extended position. When plunger 600 is in its extended position, a gap 270 is formed between plunger 600 and plug 325 of coil assembly 300. Gap 270 is relatively small, with a distance of, for example, about 0.031 inches. Additionally, when plungers 600, 700 are in their respective extended positions, a gap 275 is formed between upper body 620 of plunger 600 and upper body 710 of plunger 700. Gap 275 is relatively small, with a distance of, for example, about 0.173 inches.

[0059] When the valve 100 is in its closed state, the inlet side pressure of the cryogenic fluid at the inlet side 230 of the conduit 215 is greater than the outlet side pressure of the cryogenic liquid at the outlet side 235 of the conduit 215. Further, the inlet side pressure of the cryogenic fluid at the inlet side 230 is greater than or equal to the chamber pressure of the fluid within the chamber 265. For example, initially after the valve transitions to its closed state, the inlet side pressure at the inlet side 230 is greater than the chamber pressure in the chamber 265. Over time, as the valve 100 remains in its closed state, the bleeder seal 920 allows fluid to slowly bleed between the inlet side 230 and the chamber 265. The chamber pressure in the chamber 265, in turn, slowly increases to equalize with the inlet side pressure at the inlet side 230, which subsequently promotes the valve 100 to transition from its closed state. The chamber pressure in the chamber 265 increases such that it is greater than the outlet side pressure to further maintain the poppet valve 400 in its closed position.

[0060] Figure 11 The valve 100 is depicted in its intermediate state. To transition the valve 100 from its closed state Figure 10 ) to its intermediate state Figure 11 ), the coil 320 of the coil assembly 300 transitions to its energized state. When the coil 320 is energized, the coil 320 generates a magnetic field that pulls the plunger 600 up to its retracted position. As shown in the illustrated example, the plunger 600, in its retracted position, engages the plug 325 of the coil assembly 300 such that the gap 270 is zero. Further, the magnetic field of the coil 320 initially pulls the plungers 600, 700 together up such that the plunger 700 transitions to its partially retracted position. That is, the plungers 600, 700 and the pin 800 are arranged such that the plunger 700 translates up with the plunger 600 when the coil 320 transitions to the energized state. For example, the plungers 600, 700 and the springs 810, 820 are arranged such that the biasing force of the springs 810, 820 is overcome by the force exerted on the plunger 600 by the coil 320 such that the plunger 700 moves up as one unit with the plunger 600. The gap 275, in turn, remains between the upper body 620 of the plunger and the upper body 710 of the plunger 700.

[0061] At the same time, when the coil 320 is energized due to the chamber pressure in the chamber 265 being greater than the outlet side pressure and / or the biasing force of the spring 820 being relatively weak, the poppet valve 400 is arranged to initially remain in its closed position. The poppet valve 400, in turn, remains in sealing engagement with the valve seat 240 to maintain the outlet side 235 fluidly disconnected from the inlet side 230 such that cryogenic fluid is prevented from flowing through the conduit 215. With the plunger 700 in its partially retracted position and the poppet valve 400 remaining in its closed position, the ball 750 of the plunger 700 disengages from the seat 450 to fluidly connect the chamber 265 to the outlet side 235 via the opening of the guide hole 470.

[0062] With the guide hole 470 open, the chamber pressure in the chamber 265 then decreases to equalize with the outlet side pressure when the valve 100 is in its intermediate state. For example, initially after the valve transitions to its intermediate state, the chamber pressure in the chamber 265 decreases such that the inlet side pressure at the inlet side 230 is greater than the chamber pressure. Both the inlet side pressure of the inlet side 230 and the chamber pressure in the chamber 265 remain greater than the outlet side pressure at the outlet side 235. Over time, the chamber pressure in the chamber 265 decreases to a predetermined threshold at which the poppet 400 is able to push the plunger 700 toward its open position.

[0063] Figure 12 The valve 100 is depicted in its open state in which the plunger 600 remains in its retracted position, the plunger 700 is in its retracted position, and the poppet 400 is in its open position. The ball 750 of the plunger 700 remains disengaged from the seat 450 to keep the chamber 265 fluidly connected to the outlet side 235 of the conduit 215. Additionally, the poppet 400 is disengaged from the valve seat 240 to fluidly connect the outlet side 235 of the conduit 215 with the inlet side 230. Also, when the valve 100 is in its open state, the cryogenic fluid is allowed to flow through the conduit 215. When the poppet 400 is open to allow the cryogenic fluid to flow through the conduit 215, the inlet side pressure at the inlet side 230 is greater than or equal to the outlet side pressure of the outlet side 235.

[0064] To transition the valve 100 from its intermediate state ( Figure 11 ) to its open state ( Figure 12 ), the coil 320 of the coil assembly 300 remains in its energized state. The plunger 700, in turn, remains disengaged from the seat 450 to keep the chamber 265 fluidly connected to the outlet side 235 via the guide hole 470. During this time, the chamber pressure in the chamber 265 decreases toward the outlet side pressure at the outlet side 235. Eventually, the chamber pressure in the chamber 265 decreases to a predetermined pressure threshold such that the pressure differential between the inlet side pressure at the inlet side 230 and the chamber pressure in the chamber 265 causes the poppet 400 to be pushed upward to disengage from the valve seat 240 and translate to its open position. The poppet 400, in turn, pushes the plunger 700 upward relative to the plunger 600 to its fully retracted position.

[0065] For example, when the coil 320 is initially energized and the valve 100 transitions to its intermediate state, electromagnetic forces act on both the plunger 600 and the plunger 700. Because the plunger 600 is positioned further up and closer to the plug 325, the magnetic force exerted on the plunger 600 is greater than the magnetic force exerted on the plunger 700. Thus, as the plunger 600 moves up toward the plug 325, the gap 275 still exists because the strength of the electromagnetic force acting on the plunger 700 is not sufficient to overcome the biasing force of the spring 810 and / or the spring 820. Once the poppet 400 moves up as the valve 100 transitions to its open state, the poppet 400 pushes the plunger 700 up relative to the plunger 600. When the poppet 400 is in its open position, the plunger 700 is very close to the position of the plunger 600. The magnetic force acting on the plunger 700 again increases to cause the plunger 700 to continue to move up to its fully retracted position. When the plunger 700 is in its fully retracted position, the plunger 700 is positioned close to the coil 320 such that the magnetic force of the coil 320 holds the plunger 700 in its fully retracted position.

[0066] In some examples, the predetermined pressure threshold corresponds at least in part to the biasing force of the spring 810, the spring 820, and / or the spring 830. The pressure difference between the outlet-side pressure and the chamber pressure overcomes the biasing force of one or more of the springs 810, 820, 830 to cause the plunger 700 to slide up relative to the plunger 600. Moreover, in the fully retracted position of the plunger 700, the upper body 620 of the plunger 600 and the upper body 710 of the plunger 700 cause the gap 275 to be zero. The pressure difference between the inlet-side pressure and the chamber pressure overcomes the biasing force of one or more of the springs 810, 820, 830 to cause the plunger 700 to slide up relative to the plunger 600. In its open position, the upper end of the poppet 400 engages the barrel 250 of the body 200. For example, the poppet 400 is configured to travel a distance of about 0.177 inches between its closed position and its open position.

[0067] Subsequently, when the coil 320 is de-energized, the biasing force of the spring 810 pushes the poppet 400 from its open position to its closed position with enough force that a tight sealing connection is formed between the seal 435 and the valve seat 240. That is, the spring 810 pushes the poppet 400 to sealingly engage the valve seat 240 of the body 200. The poppet 400, in turn, fluidly disconnects the outlet-side 235 from the inlet-side 230 to again prevent cryogenic fluid from flowing through the conduit 215. Moreover, the biasing force of the spring 810 pushes the plunger 700 from its fully retracted position to its extended position with enough force that a tight sealing connection is formed between the ball 750 of the plunger 700 and the seat 450 of the poppet 400. The plunger assembly 500, in turn, fluidly disconnects the outlet-side 235 from the chamber 265 to keep the poppet 400 closed until the coil 320 is re-energized.

[0068] The plunger assembly 500 of the illustrated example is configured to ensure a tight sealing connection between the poppet 400 and the valve seat 240 when the valve transitions from its open state to its closed state. For example, the plunger assembly 500 includes two plungers 600, 700 that are slidably connected together in a manner that minimizes the actuation distance of the plunger 600 (e.g., equal to the length of the gap 270). The reduced actuation distance of the plunger 600 enables the magnetic force generated by the coil 320 (e.g., about 15 N) to overcome a greater biasing force of the spring 810 to transition the valve 100 from its closed state to its open state. As a result, the spring 810 can have a greater biasing force that biases the poppet 400 toward its closed position to facilitate the poppet 400 forming a sealing connection with the engaged valve seat 240 when the valve 100 transitions to the closed state.

[0069] Figure 13 Another example embodiment of a valve 1000 (also referred to as an "electromagnetic directional valve") is illustrated. The valve 1000 is configured to control the flow of cryogenic fluids (e.g., liquid hydrogen (LH2)). The valve 1000 includes components that are the same as or substantially similar to the components of the valve 100. For example, the valve 1000 includes a body 1200; a coil assembly 1300; a plunger assembly 1500; springs 1810, 1820, 1830; and a leak-off seal 1920 that are the same as or substantially similar to the body 200; the coil assembly 300; the plunger assembly 500; the springs 810, 820, 830; and the leak-off seal 1920 of the valve 100, respectively. In addition, the plunger assembly 1500 includes a plunger 1600, a plunger 1700, and a pin 1800 that are the same as or substantially similar to the plunger 600, the plunger 700, and the pin 800 of the valve 100, respectively. As such, some features of those components of the valve 1000 are not disclosed in further detail below.

[0070] Figure 14Further depicting the poppet valve 1400 of the valve 1000 when assembled with the plunger assembly 1500. The poppet valve 1400 is configured to operate the same as or substantially similar to the poppet valve 400 of the valve 100. As such, some features of the operation of the poppet valve 1400 are not further disclosed in detail below. In addition, the poppet valve 1400 includes the same or substantially similar components as the components of the poppet valve 400. For example, the poppet valve 1400 includes an upper body 1410, a cavity 1415, a lower body 1420, a bore 1425, a head 1430, a seal 1435, a cap 1440, a seat 1450, and a guide hole 1470 that are the same as or substantially similar to the upper body 410, the cavity 415, the lower body 420, the bore 425, the head 430, the seal 435, the cap 440, the seat 450, and the guide hole 470, respectively, of the poppet valve 400. As such, some features of those components of the valve 1000 are not further disclosed in detail below.

[0071] As Figure 14 The poppet valve 1400 also includes a winged flange 1480 extending radially outward from the lower body 1420, as explained in the

[0072] An example solenoid valve for cryogenic fluids includes a valve body. The valve body includes a first seat and defines a conduit having an inlet side and an outlet side. The solenoid valve includes a coil assembly coupled to the valve body. The solenoid valve includes a poppet configured to translate between a closed position in which the poppet sealingly engages the first seat to fluidly disconnect the inlet side from the outlet side and an open position in which the poppet disengages from the first seat to fluidly connect the inlet side and the outlet side. The poppet and the valve body at least partially define a chamber. The poppet defines a guide hole configured to fluidly connect the chamber and the outlet side. The poppet includes a second seat adjacent to the guide hole. The solenoid valve includes a plunger assembly positioned in the chamber. The plunger assembly includes a first plunger positioned such that the coil assembly is configured to translate the first plunger between a first extended position and a first retracted position. The plunger assembly includes a second plunger slidably coupled to the first plunger and extending toward the poppet. The second plunger is configured to translate between a second extended position, a partially retracted position, and a second retracted position. The second plunger is configured to sealingly engage the second seat to close the guide hole in the second extended position and configured to disengage from the second seat to open the guide hole in the partially retracted position and the second retracted position.

[0073] In some examples, the valve body further includes a main body including the first seat, the inlet side, and the outlet side. The valve body further includes a barrel extending between and coupled to the main body and the coil assembly. The barrel and the poppet at least partially define the chamber.

[0074] In some examples, the coil assembly includes a coil configured to position the first plunger in the first extended position in a de-energized state and to position the first plunger in the first retracted position in an energized state.

[0075] In some examples, the second plunger includes a ball configured to sealingly engage the second seat of the poppet when the second plunger is in the second extended position.

[0076] In some examples, the plunger assembly further includes a pin configured to slidably couple the second plunger to the first plunger. In some such examples, the pin is fixed to the second plunger. The first plunger defines a vertical slot through which the pin slidably extends to enable the second plunger to slide relative to the first plunger. The vertical slot includes an upper end and a lower end. The pin is configured to slide from the lower end to the upper end when the second plunger translates to the second retracted position and the poppet valve translates to the open position.

[0077] Some examples further include a leakage seal positioned between the poppet valve and the valve body to slowly equalize a chamber pressure within the chamber over time with a chamber pressure of an inside of the valve body when the poppet valve is in the closed position.

[0078] Some examples further include a first spring extending between and engaging the coil assembly and the second plunger to bias the second plunger toward the second extended position and to bias the poppet valve toward the closed position. Some examples further include a second spring extending between and engaging the second plunger and the poppet valve to further bias the second plunger toward the second extended position. Some examples further include a third spring extending between and engaging the first plunger and the second plunger to bias the first toward the first extended position when the second plunger is in the second extended position.

[0079] In some examples, when the solenoid valve is in a closed state, the poppet valve is in the closed position and sealingly engaged with the first seat to fluidly disconnect the inlet side of the valve body from the outlet side, the first plunger is in the first extended position, the second plunger is in the second extended position and sealingly engaged with the second seat to fluidly disconnect the chamber from the outlet side of the valve body, and an inlet side pressure of the inlet side is greater than an outlet side pressure of the outlet side and greater than or equal to a chamber pressure of the chamber.

[0080] In some examples, when the solenoid valve is in the intermediate state, the poppet valve is in the closed position and sealingly engaged with the first seat to fluidly disconnect the inlet side of the valve body from the outlet side, the first plunger is in the first retracted position, the second plunger is in the partially retracted position and disengaged from the second seat to fluidly connect the chamber to the outlet side to enable the chamber to equalize with the outlet side, and an inlet side pressure at the inlet side is greater than a chamber pressure in the chamber and the chamber pressure is greater than or equal to an outlet side pressure of the outlet side.

[0081] In some examples, the solenoid valve is configured to transition from a closed state to an intermediate state when the coil assembly transitions to an energized state. The coil assembly transitioning to the energized state is configured to translate the first plunger as a unit to the first retracted position and to translate the second plunger as a unit to the partially retracted position.

[0082] In some examples, when the solenoid valve is in the open state, the poppet valve is in the open position and disengaged from the first seat to fluidly connect the inlet side of the valve body with the outlet side, the first plunger is in the first retracted position, the second plunger is in the second retracted position and disengaged from the second seat to fluidly connect the chamber to the outlet side, and an inlet side pressure at the inlet side is greater than or equal to an outlet side pressure of the outlet side.

[0083] In some examples, the solenoid valve is configured to transition from an intermediate state to an open state when the coil assembly remains in an energized state and a chamber pressure in the chamber decreases to a predetermined pressure threshold such that a pressure differential between the chamber pressure and an inlet side pressure at the inlet side causes the poppet valve to be pushed upward to disengage from the first seat and translate to the open position.

[0084] In some examples, the solenoid valve is configured to transition from a closed state to an open state in response to the coil assembly transitioning to an energized state. Some such examples further include a spring configured to push the poppet valve from the open position to the closed position to sealingly engage the first seat of the valve body when the coil assembly transitions to a de-energized state.

Claims

1. An electromagnetic pilot valve for cryogenic fluids, comprising: A valve body, which includes a first seat and defines a conduit having an inlet side and an outlet side; A coil assembly coupled to the valve body; A lift valve configured to translate between a closed position and an open position, wherein in the closed position the lift valve sealably engages a first seat to fluidly disconnect the inlet side from the outlet side, and in the open position the lift valve disengages from the first seat to fluidly connect the inlet side to the outlet side, wherein the lift valve and the valve body at least partially define a chamber, wherein the lift valve defines a guide orifice configured to fluidly connect the chamber to the outlet side, and wherein the lift valve includes a second seat adjacent to the guide orifice; A plunger assembly, positioned within the chamber, includes: A first plunger is positioned such that the coil assembly is configured to translate the first plunger between a first extended position and a first retracted position. and A second plunger, slidably coupled to the first plunger and extending toward the lift valve, wherein the second plunger is configured to translate between a second extended position, a partially retracted position, and a second retracted position, wherein the second plunger is configured to sealably engage the second seat to close the guide hole in the second extended position and is configured to disengage from the second seat to open the guide hole in the partially retracted position and the second retracted position.

2. The electromagnetic pilot valve according to claim 1, wherein the valve body further comprises: The main body includes the first seat, the entrance side, and the exit side; and A cylinder that extends between and couples to the body and the coil assembly, wherein the cylinder and the lift valve at least partially define the chamber.

3. The electromagnetic pilot valve of claim 1, wherein the coil assembly includes a coil configured to position the first plunger in the first extended position in a de-energized state and to position the first plunger in the first retracted position in a energized state.

4. The electromagnetic pilot valve of claim 1, wherein the second plunger comprises a ball configured to sealably engage the second seat of the lift valve when the second plunger is in the second extended position.

5. The electromagnetic pilot valve of claim 1, wherein the plunger assembly further comprises a pin configured to slidably couple the second plunger to the first plunger.

6. The solenoid valve of claim 5, wherein the pin is fixed to the second plunger, wherein the first plunger defines a vertical groove, the pin extending slidably through the vertical groove to allow the second plunger to slide relative to the first plunger, wherein the vertical groove includes an upper end and a lower end, wherein the pin is configured to slide from the lower end to the upper end when the second plunger is translated to the second retracted position and the lift valve is translated to the open position.

7. The electromagnetic pilot valve of claim 1, further comprising a venting seal positioned between the lift valve and the valve body to allow the chamber pressure in the chamber to slowly equalize with the chamber pressure inside the valve body over time when the lift valve is in the closed position.

8. The electromagnetic pilot valve according to claim 1, further comprising: A first spring extends between the coil assembly and the second plunger and engages the coil assembly and the second plunger to bias the second plunger toward the second extended position and the lift valve toward the closed position; A second spring extends between the second plunger and the lift valve and engages the second plunger and the lift valve to further bias the second plunger toward the second extended position; and A third spring extends between the first plunger and the second plunger and engages the first plunger and the second plunger to bias the first plunger toward the first extended position when the second plunger is in the second extended position.

9. The electromagnetic pilot valve according to claim 1, wherein, When the solenoid pilot valve is in the closed state: The lift valve is in the closed position and is sealed to the first seat to fluidly disconnect the inlet side from the outlet side of the valve body; The first plunger is in the first extended position; The second plunger is in the second extended position and is sealingly engaged with the second seat to fluidly disconnect the chamber from the outlet side of the valve body; and The inlet-side pressure is greater than the outlet-side pressure and is greater than or equal to the chamber pressure.

10. The electromagnetic pilot valve according to claim 1, wherein, When the solenoid pilot valve is in the intermediate state: The lift valve is in the closed position and is sealed to the first seat to fluidly disconnect the inlet side from the outlet side of the valve body; The first plunger is in the first retracted position; The second plunger is in the partially retracted position and disengaged from the second seat to fluidly connect the chamber to the outlet side so that the chamber can be balanced with the outlet side; and The inlet-side pressure at the inlet side is greater than the chamber pressure in the chamber, and the chamber pressure is greater than or equal to the outlet-side pressure at the outlet side.

11. The electromagnetic pilot valve of claim 1, wherein the electromagnetic pilot valve is configured to transition from a closed state to an intermediate state when the coil assembly is switched to an energized state, wherein the coil assembly switched to the energized state is configured to cause the first plunger to translate together as a unit to the first retracted position and the second plunger to translate together as a unit to the partially retracted position.

12. The electromagnetic pilot valve according to claim 1, wherein, When the solenoid pilot valve is in the open state: The lift valve is in the open position and disengaged from the first seat to fluidly connect the inlet side and the outlet side of the valve body; The first plunger is in the first retracted position; The second plunger is in the second retracted position and disengaged from the second seat to fluidly connect the chamber to the outlet side; and The inlet-side pressure at the inlet side is greater than or equal to the outlet-side pressure at the outlet side.

13. The solenoid pilot valve of claim 1, wherein the solenoid pilot valve is configured to transition from an intermediate state to an open state when: The coil assembly remains energized; and The chamber pressure in the chamber decreases to a predetermined pressure threshold, causing the pressure difference between the chamber pressure and the inlet side pressure at the inlet side to push the lift valve upward to disengage from the first seat and translate it to the open position.

14. The electromagnetic pilot valve of claim 1, wherein the electromagnetic pilot valve is configured to change from a closed state to an open state in response to the coil assembly being switched to an energized state.

15. The electromagnetic pilot valve of claim 14, further comprising a spring configured to push the lift valve from the open position to the closed position to sealably engage the first seat of the valve body when the coil assembly is switched to a de-energized state.

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