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Title:
SOLENOID CONTROLLED VALVE ASSEMBLY INCLUDING A PRESSURE BALANCING DIAPHRAGM
Document Type and Number:
WIPO Patent Application WO/2018/208851
Kind Code:
A1
Abstract:
A proportional solenoid-controlled fluid valve assembly having a fluid pressure balancing diaphragm. The valve assembly also includes a solenoid coil assembly and a magnetic orifice piece positioned within. A plunger is positioned within the coil and is movable between a de-actuated and an actuated position. The pressure balancing diaphragm has a U-shaped portion with the diaphragm positioned within the valve base and the U-shaped portion abutting the valve seat. A retainer is also provided extending through the diaphragm opening and an aperture formed in the plunger. A magnetic frame is also included for securing the valve assembly in an assembled configuration, wherein a magnetic path is formed by magnetic orifice piece, plunger and the magnetic frame. The solenoid coil is actuated such that the plunger moves towards the magnetic orifice piece lifting the diaphragm and retainer allowing pressurized media to pass from the inlet port to the outlet port.

Inventors:
KUMAR VIRARAGHAVEN (US)
KULKAMI SUDHIR (US)
PRADHANANGA SHAILESH (US)
Application Number:
PCT/US2018/031691
Publication Date:
November 15, 2018
Filing Date:
May 08, 2018
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
KUMAR VIRARAGHAVEN S (US)
KULKAMI SUDHIR (US)
PRADHANANGA SHAILESH (US)
International Classes:
F16K39/02
Foreign References:
US4858886A1989-08-22
US20050184261A12005-08-25
US20180172176A12018-06-21
US6076550A2000-06-20
US4844112A1989-07-04
Attorney, Agent or Firm:
TAPSCOTT, Rebecca, M. K. (US)
Download PDF:
Claims:
We claim:

1. A valve assembly comprising: a valve base including an upper cavity forming an annular ledge, a fluid inlet port and an outlet port with an internal passageway and interior valve cavity there between, said internal passageway terminating at a valve seat;

a solenoid coil assembly including a bobbin, having a cylindrical conduit, and a solenoid coil;

a magnetic orifice piece positioned within the conduit and having a body portion with a first end and a second end, a rim portion, and an bore formed there through;

a plunger having a first end and a second end with an aperture formed therein, said plunger being positioned within the cylindrical conduit of the bobbin and being movable within the conduit between a de-actuated position and an actuated position;

a diaphragm having a top side, a bottom side, an outer annular flange portion, and an inner annular flange terminating at a diaphragm opening with an annular U-shaped portion therebetween, said diaphragm being positioned within valve base with said outer annular flange portion abutting the ledge of the valve base and the U-shaped portion contacting the valve seat; a retainer having a top cylindrical upstanding portion extending through the diaphragm opening and into the aperture of the plunger; and

a magnetic frame for securing the valve assembly in an assembled configuration, wherein a magnetic path is formed by magnetic orifice piece, plunger and the magnetic frame and the solenoid coil is configured to be actuated such that the plunger moves towards the magnetic orifice piece, thus lifting the retainer and diaphragm and allowing pressurized media to pass from the inlet port to the outlet port.

2. The valve assembly of claim 1, wherein the plunger includes a fluid flow passageway formed therein connecting the aperture to a side port.

3. The valve assembly of claim 1, wherein the retainer includes a fluid flow passageway formed therein to allow pressurized media from the inlet port to pass to the top side of the diaphragm and fill a cavity around the diaphragm, wherein said diaphragm acts as a pressure balance to balance a force that is exerted on a bottom side of the diaphragm and the force that is exerted on a mean convoluted diameter of the diaphragm on a top side.

4. The valve assembly of claim 1, wherein a radial air gap exists between said plunger and said magnetic orifice piece.

5. The valve assembly of claim 1, wherein the retainer has a cylindrical body with the top cylindrical upstanding portion, a stepped ledge portion, and a bottom face, and wherein the stepped ledge portion of the retainer abuts the inner annular flange of the diaphragm.

6. The valve assembly of claim 5, wherein said bobbin has a top flange and a bottom flange connected by the cylindrical conduit, said cylindrical conduit including an extension projecting from the bottom flange for extending into the valve base. 7. The valve assembly of claim 6, further comprising a split ring having first and second halves, and wherein said bobbin further includes an engagement flange sandwiched between a top surface of the outer annular flange of the diaphragm and a bottom surface of the split ring, said split ring being formed of a magnetic material and configured to provide a magnetic radial path between the plunger and the frame.

8. The valve assembly of claim 1, wherein said rim portion of the magnetic orifice piece extends proximate to the first end of the body portion and having a top side and a bottom side, said body portion of the magnetic orifice piece further includes an upper section extending on a first side of the rim portion and an elongated lower portion extending on a second side of the rim portion and being positioned within the cylindrical conduit of the bobbin with the second side of the rim portion abutting a top flange of the bobbin.

9. The valve assembly of claim 1, wherein said bobbin further includes a retaining flange for extending into the valve base and retaining the outer annular flange of the diaphragm.

10. The valve assembly of claim 1, wherein the valve assembly further includes a ring positioned on the ledge of the valve base for securing the diaphragm within the valve base, said ring being formed of a magnetic material and configured to provide a magnetic radial path between the plunger and the frame. 11. The valve assembly of claim 1, wherein the magnetic frame has a unitary C-shape construction with a top section, a bottom section, and a side section, wherein the bottom section is adapted to slide along the valve base to be secured within slots formed in the valve base positioned adjacent to a top end of the valve base. 12. The valve assembly of claim 11, wherein the top section of the magnetic frame engages a top extension of the magnetic orifice piece to further secure and restrict rotation of the valve assembly.

13. A valve assembly comprising: a valve base including an upper cavity forming an annular ledge, a fluid inlet port and an outlet port with an internal passageway therebetween, said internal passageway terminating at a valve seat;

a solenoid coil assembly including a bobbin and a solenoid coil, said bobbin having a top flange and a bottom flange connected by a cylindrical conduit, said cylindrical conduit including an extension projecting from the bottom flange for extending into the valve base; a magnetic orifice piece having a body portion with a first end and a second end, a rim portion, and an bore formed therethrough, said rim portion extending proximate to the first end of the body portion, said body portion being positioned within the cylindrical conduit of the bobbin with the rim portion abutting the top flange of the bobbin;

a plunger having a first end, a second end with an aperture formed therein, and a cylindrical sidewall, said plunger positioned within the conduit of the bobbin such that the first end of the plunger is adjacent to the second end of the magnetic orifice piece, said plunger being movable within the conduit between a de-actuated position and an actuated position; a diaphragm having a top side, a bottom side, an outer annular- flange portion, and an inner annular flange terminating at a diaphragm opening with an annular U-shaped portion therebetween, said diaphragm being positioned within valve base with said outer annular flange portion abutting the ledge of the valve base and the U-shaped portion contacting the valve seat; a retainer having a cylindrical body with a top cylindrical upstanding portion, a stepped ledge portion, and a bottom face, wherein the stepped ledge portion of the retainer abuts the inner annular flange of the diaphragm; and

a magnetic frame for securing the valve assembly in an assembled configuration, wherein a magnetic path is formed by magnetic orifice piece, plunger and the magnetic frame and the solenoid coil is configured to be actuated such that the plunger moves towards the magnetic orifice piece, thus lifting the retainer and allowing pressurized media to pass from the inlet port to the outlet port.

14. The valve assembly of claim 13, wherein the plunger includes a fluid flow passageway formed between the aperture of the second end and the sidewall.

15. The valve assembly of claim 14, the retainer includes a fluid flow passageway formed therein to allow pressurized media from the inlet port to pass to the top side of the diaphragm and fill a cavity around the diaphragm, wherein said diaphragm acts as a pressure balance to balance a force that is exerted on a bottom side of the diaphragm and the force that is exerted on a mean convoluted diameter of the diaphragm on a top side.

16. The valve assembly of claim 13, wherein the valve assembly further includes a ring positioned on the ledge of the valve base for securing the diaphragm within the valve base, said ring being formed of a magnetic material and configured to provide a magnetic radial path between the plunger and the frame.

17. The valve assembly of claim 13, wherein said bobbin further includes a retaining flange for extending into the valve base and retaining the outer annular flange of the diaphragm.

18. The valve assembly of claim 13, wherein the valve assembly further includes a ring positioned on the ledge of the valve base for securing the diaphragm within the valve base, said ring being formed of a magnetic material and configured to provide a magnetic radial path between the plunger and the frame.

19. The valve assembly of claim 13, further comprising a split ring having first and second halves, and wherein said bobbin further includes an engagement flange sandwiched between a top surface of the outer annular flange of the diaphragm and a bottom surface of the split ring, said split ring being formed of a magnetic material and configured to provide a magnetic radial path between the plunger and the frame.

20. The valve assembly of claim 13, wherein a radial air gap exists between said plunger and said magnetic orifice piece.

Description:
Solenoid Controlled Valve Assembly including a Pressure Balancing Diaphragm

FIELD OF INVENTION

The present application relates in general to solenoid-actuated fluid control valves for use in fluid flow regulation systems, such as those that require precise control of the rate of fluid flow, including but not limited to pneumatic and hydraulic regulation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG Lis an assembled cross-sectional view of a pressure balancing valve with diaphragm sealing.

FIG. 2A is an exploded view of the pressure balancing valve with diaphragm sealing of Fig. 1. FIG. 2B is an enlarged, cross-sectional view of the pressure balancing valve with diaphragm sealing of Fig. 1.

Figs. 3 A-3D illustrate perspective front, perspective back, cross-sectional, and top views of a valve base.

FIGs. 4A and 4B are top and cross-sectional views of a retainer.

FIGs. 5A-5C are perspective, side and cross-sectional views of plunger.

FIGs. 6A and 6B are top and cross-sectional views of a diaphragm.

FIGs. 7A and 7B illustrate perspective and cross-sectional views of a solenoid assembly having a bobbin and solenoid coil.

FIGs. 7C and 7D illustrate perspective and cross-sectional views of a bobbin without solenoid coil attached.

FIGs. 8A-8B are side and cross-sectional views of a magnetic orifice piece.

FIGs. 9A-9B are perspective and side views of a magnetic frame.

FIG. 10 is a cross-sectional view of an isolation valve assembly with diaphragm sealing. FIGs. 11 and 12 are additional embodiments of a pressure balancing valve with diaphragm sealing and isolation valve with diaphragm sealing.

FIGs. 13A and 13B are side and cross-sectional views of an alternate bobbin configuration. FIG. 14 is an enlarged perspective view of a split ring.

FIGs. 15 and 16 illustrate cross-sectional and exploded views of an additional embodiment of a valve assembly 510 with a modified adjustment screw and frame.

FIGs. 17A and 17B are enlarged perspective and side views of an adjustment screw.

FIGS. 18A and 18B are perspective and side views of a frame.

FIG. 19 is a cross-sectional view of an additional embodiment of a valve assembly with diaphragm sealing.

FIGs 20a and 20b are side and cross- sectional views of a bobbin with a coil winding of the valve assembly of FIG. 19.

FIG. 21 is an enlarged view of the valve assembly of FIG. 19, showing air gaps in the assembly. BRIEF SUMMARY

A proportional solenoid-controlled fluid valve assembly having a fluid pressure balancing arrangement according to the embodiments described herein is designed such that balancing and sealing are achieved with a retainer and diaphragm. The valve assembly includes a valve base having an upper cavity forming an annular ledge, a fluid inlet port and an outlet port with an internal passageway and interior valve cavity there between, with the internal passageway terminating at a valve seat. The valve assembly also includes a solenoid coil assembly having a cylindrical conduit and a magnetic orifice piece positioned within the conduit. A plunger is positioned within the conduit and is movable within the conduit between a de-actuated position and an actuated position. A pressure balancing diaphragm is provided having a top side, a bottom side, an outer annular flange portion, a U-shaped portion, and an inner annular flange terminating at a diaphragm opening, with the diaphragm being positioned within valve base with the outer annular flange portion abutting the ledge of the valve base and the U-shaped portion abutting the valve seat. A retainer is provided having a top cylindrical upstanding portion extending through the diaphragm opening and an aperture formed in the plunger. A magnetic frame is also included for securing the valve assembly in an assembled configuration, wherein a magnetic path is formed by magnetic orifice piece, plunger and the magnetic frame and the solenoid coil is configured to be actuated such that the plunger moves towards the magnetic orifice piece, thus lifting the diaphragm and retainer and allowing pressurized media to pass from the inlet port to the outlet port. DETAILED DESCRIPTION

The valve assemblies described in the present disclosure are proportional solenoid- controlled fluid valves having a fluid pressure balancing arrangement designed such that balancing is achieved with diaphragm serving dual purpose of balancing and sealing. Valves described in the present disclosure are designed to be easy to assemble and use fewer fasteners and threaded members. Fewer parts and lower wattage are required to achieve the valve function as compared with other valves. In operation, a force results from the pressure acting on a bottom side of the diaphragm is balanced by a force resulting from pressure acting on a top side of the diaphragm. Due to proper force balancing, the solenoid may operate at low wattage as it only has to overcome a spring force. The components and mechanisms of pressure balancing valve 10 are described in detail below.

FIG. 1 is a cross-sectional view of valve assembly 10. FIG. 2A is an exploded view of valve assembly 10 and FIG. 2B is an enlarged view of a portion of valve assembly 10 showing radial gaps. Valve assembly 10 includes a valve vase 15, a plunger 20, a retainer 25, a diaphragm 30, a solenoid coil assembly 35, a top pole piece 40, a ring 45, a magnetic frame 50, a spring 55, an adjustment screw 60, and one or more O-rings 65. In the embodiment of FIG. 1, valve assembly 10 allows pressurized media from a fluid inlet port 108 to pass through interior valve bore 110, thereby exerting pressure on a bottom of diaphragm 30 and retainer 25 towards a hole in retainer 25 and plunger 20. This allows the pressurized media from inlet port 108 to pass to the top side of diaphragm 30. In this case, diaphragm 30 acts as a pressure balance, balancing the force that is exerted on bottom side of the diaphragm 158 over the valve seat orifice 112 and the force that is exerted on the mean convoluted diameter of the diaphragm, i.e. U-shaped portion 152, on the top side 157. Diaphragm 30 acts as a sealing member, which provides a true balancing effect, as the mean convoluted diameter of diaphragm 30 is the same as the diameter of valve orifice 1 11, and generally circular valve seat 112. Hence, the force acted on the top 157 and bottom side 158 of diaphragm 30 due to pressurized fluid is equal and opposite and is nullified. Thus, the only force solenoid has to overcome is the spring force. Diaphragm 30 acts such that the solenoid coil requires less energy to actuate, allowing it to operate at very low wattage. When a solenoid coil of solenoid coil assembly 35 is actuated, plunger 20 is attracted towards the top pole piece 40 and moves to close air gap 199 by overcoming the bias of spring 55 and lifting diaphragm 30, thereby allowing the pressurized media to pass from inlet port 108 to outlet port 102.

As illustrated by the exploded view shown in FIG. 2A, valve assembly can be assembled by attaching retainer 25 and diaphragm 30 to plunger 20. Retainer 25, diaphragm 30, and plunger 20 are then placed into a cavity 113 of valve base 15 such that an outer portion of diaphragm 30 contacts a cavity annular ledge 115. Ring 45 is then placed over plunger 20 such that ring 45 contacts a top side of diaphragm 30. A bobbin 36 of solenoid coil assembly (coil not shown) is then placed over plunger 20 and ring 45. Top pole piece 40 is then inserted into bobbin 36 and an adjustment screw 60 is inserted to help secure the assembly. Magnetic frame 50 is then attached to secure the valve assembly in an assembled configuration.

The components of valve assembly 10 will be described in detail with respect to FIGs. 3A-9B. Figs. 3A-3D illustrate perspective front, perspective back, cross-sectional, and top views of valve base 15. Valve base 15 may be formed of plastic, aluminum, machined steel, or the like and includes a fluid input port 108 and fluid exit port 102. Valve base 15 also includes an interior valve cavity 106. Fluid exit port 102 is coupled to a first generally cylindrical interior valve bore 110 that extends to a valve orifice 111, which is surrounded by a generally circular valve seat 112. Valve orifice 111 of interior valve bore 110 is surrounded by interior valve cavity 106 in which diaphragm 30 is retained. Valve base 15 also includes an upper cavity 113 connected to interior valve cavity 106 by a connecting channel 114. Cavity 113 forms an annular ledge 115. Valve base 15 includes a top end 116a, a bottom end 116b, a port side 116c and a back side 116d having apertures 117a formed therein. Apertures 117b are also provided on port side 116c. Further, slots 118 are formed within port side 1 16c and back side 116d of valve base 15 adjacent to top end 116a to allow for insertion of magnetic frame 50. An annular opening 119 is also formed within end 116a of valve base 15.

FIGs. 4 A and 4B are top and cross-sectional views of retainer 25. Materials used for forming retainer include elastomeric materials. Retainer 25 may be integrally formed or inseparably attached to diaphragm 30. Alternatively, retainer 25 may be a separate component. As shown in FIG. 4B, retainer 25 includes a generally cylindrical body having a top cylindrical upstanding portion 120 with an inwardly tapered end 122, a stepped ledge portion 124 which terminates at a lower generally circular retainer face 130. Cylindrical upstanding portion 120 is generally sized to engage with plunger 20.

Perspective, side and cross-sectional views of plunger 20 are shown in FIGs. 5A-5C. Plunger 20 includes a first end 140 and a second end 142 with a generally cylindrical side wall 143 having a narrowed cylindrical section 144 and ledge 145 formed at first end 140. Second end includes an aperture 146 leading to a fluid passageway 147 and a side port 148, which terminates at a side opening 149 of formed in cylindrical side wall 143.

Top and cross-sectional views of diaphragm 30 are shown in FIGs. 6A and 6B.

Diaphragm 30 is formed from an elastomeric material and includes an outer annular flange portion 150, an annular generally U-shaped portion 152 where the mean diameter of the diaphragm is present, and an inner annular flange 154, which terminates at a diaphragm opening 156. Diaphragm 30 also generally includes a top side 157 and a bottom side 158. During assembly of valve 10, diaphragm 30 is positioned within valve base 15 such that annular flange 150 of diaphragm 30 contacts ledge 115 of valve base 15. Generally U-shaped portion 152 of diaphragm 30 extends downwardly through connecting channel 114 towards interior valve cavity 106 and contacts the valve seat. Inner annular flange 154 stepped ledge portion 124 of retainer 25 and top cylindrical upstanding portion 120 of retainer 25 extends through diaphragm opening 156.

Coil assembly 35 is shown in FIGs. 7A-7D. In particular, FIGs. 7A and 7B illustrate perspective and cross-sectional views of coil assembly 35 having a bobbin 161 and coil 162. FIGs. 7C and 7D illustrate perspective and cross-sectional views, respectively, of bobbin 161 without solenoid coil attached. Bobbin 161 includes a top cylindrical flange 163 and a bottom cylindrical flange 164 connected by a cylindrical conduit 165 with a though hole 166 therein. Bottom cylindrical flange 164 includes an inward stepped portion 167 for engaging top annular opening 119 of valve base 15. Cylindrical conduit 165 includes an extension 168 extending downward from bottom cylindrical flange 164 for extending into valve base 15, as shown in FIGs. l and 2B.

As shown in side and cross-sectional views in FIGs. 8A-8B, respectively, valve assembly 10 further includes a fixed magnetic orifice piece 40 positioned over plunger 20. In general, magnetic orifice piece 40 is made of a ferromagnetic material and is cylindrically shaped with an outer surface 170 and bore 171 formed therein, which extends from a top end 173 to a bottom end 174. Bore 171 includes a lower portion 176, an intermediate width middle portion 177, and a wider upper portion 178. Outer surface 170 includes a groove 179 formed therein for receiving an O-ring 65, as shown in FIG. 1. Magnetic orifice piece 40 also includes a downwardly extending bottom rim 181 having a slanted outer edge 182 and a disk- shaped rim portion 185 extending outwardly from top end 173. Bottom rim 181 of magnetic orifice piece 40 is sized to fit over narrowed cylindrical section 144 of plunger 20. In an assembled

configuration, disk-shaped rim portion 185 is positioned between top cylindrical flange 163 of bobbin 161 and magnetic frame 50. Magnetic orifice piece 40 also includes a top extension 202 for fitting within a slot of magnetic frame 50 to secure the valve assembly 10 and prevent rotation.

A flux conductor or magnetic frame 50 is provided to complete valve assembly 10. As illustrated in detail in perspective and side views in FIGs. 9A-9B, respectively, magnetic frame 50 has a unitary generally C-shape construction. In particular, magnetic frame 50 includes a top section 190, a bottom section 191, and a side section 192. Top section 190 includes an elongated opening 194 formed therein. A notch 195 may also be formed within a lower surface of top section 195. Projections 196 bend at notch 195 perpendicularly from top section 190 to secure magnetic frame 50 to valve assembly 10. Bottom section 191 also includes an elongated opening 197 forming prongs 198 for engaging slots 118 in base section 15. As shown in FIGs. 1-2B, a ring 45 is also provided to secure the assembly of valve 10 and to sandwich diaphragm 30 between ring 45 and valve base 15. Ring 45 is formed of a magnetic material and serves dual purposes. Ring 45 provides an additional magnetic radial path between plunger 20 and frame 50 and also functions as a spacer between frame 50 and coil assembly 35 to hold diaphragm 30 in place.

With reference to FIG. 2B, the fixed magnetic orifice piece 40, axially movable plunger 20, frame 50, and ring 45 are made of magnetic materials. Plunger 20 and orifice piece 40 are placed in such a way that an air gap 199 exists between them. A magnetic path is formed by orifice piece 40, plunger 20 and frame 50. Spring 55 is used as a biasing member. When solenoid coil 162 is actuated, plunger 20 is attracted towards the orifice piece 40 and plunger 20 moves to close air gap 99 against spring 55, thus lifting diaphragm 30 which, in turn, allows the pressurized media to pass from inlet port 108 to outlet port 102. In particular, when solenoid coil 162 is energized, a magnetic field goes around flux conductor or magnetic frame 50 so the magnetic field comes through ring 45 and jumps a thin radial air gap 201. After the magnetic field jumps thin radial air gap 201 it goes around magnetic frame 50 and makes contact between magnetic frame 50 and magnetic orifice piece 40 so the magnetic field comes through magnetic orifice piece 40 and then jumps an air gap 199 between magnetic orifice piece 40 and plunger 20. The magnetic field then flows through plunger 20, thereby creating a magnetic force that pulls plunger 20 towards magnetic orifice piece and compresses spring 55. Depending on the intensity or strength of coil 162, the position of plunger 20 can be held in various positions thus controlling the flow between inlet port 108 and outlet port 102. Retainer 25 is connected to plunger 20 so that when plunger 20 is pulled towards magnetic orifice piece 40, diaphragm 30 is lifted off the valve seat. As shown in Fig. 1, U-shaped portion 152 of diaphragm 30 contacts valve seat 112 over orifice 111 when valve 10 is in a de-actuated state, so that the media from inlet port 108 is prevented from passing to outlet port 102. Frame 50 holds together all the parts of valve 10, thus eliminating the need of an additional member to hold the complete assembly. Diaphragm 30, as shown, is sandwiched between plunger 20 and retainer 25, separating the fluid path in valve base 15 and an area above diaphragm 30. One side of the diaphragm rests on the valve base orifice 111 and is held in place by bobbin 161 and ring 45, when frame 50 is inserted in place. Top section 190 of frame 50 rests on disk-shaped rim portion 185 and secures a top extension 202 of orifice piece 40 within slot 194 to further secure the valve assembly 10.

The embodiment shown in FIG. 10, is an isolation valve assembly 210, wherein a retainer 225 and plunger 200 are solid and do not include fluid flow apertures therein. Each of the remaining components of valve assembly 210 is consistent with the components described in connection with valve assembly 10 and will not be separately described. When pressurized media is acted on inlet port 108, the forces acted on the bottom of diaphragm 30, seated on orifice valve seat 112, need to be balanced by the spring force to prevent diaphragm 30 from lifting off valve seat 112. Diaphragm 30 serves in isolating the media from entering interior valve cavity 106. When valve 210 is actuated, plunger 20 is attracted towards top pole 40, against spring 55, and diaphragm 30 is lifted off valve seat 112, thereby allowing the media to pass from inlet port 108 to outlet port 102 confining the media in interior valve cavity 106. An additional embodiment of a pressure balancing valve 310 is shown in FIG. 11 and an addition embodiment of an isolation valve 410 is shown in FIG. 12. Each of pressure balancing valve 310 and isolation valve 410 include an alternate bobbin 336 and a split ring 345. The remaining components of pressure balancing valve assembly 310 are equivalent to the components described in connection with valve assembly 10. Similarly, the remaining components of isolation valve assembly 410 are equivalent to the components described in connection with isolation valve assembly 210.

Side and cross-sectional views of alternate bobbin 336 are shown in FIGs. 13A and 13B, in connection with a solenoid coil assembly 335 including a coil 362. Bobbin 336 includes a top cylindrical flange 363 and a bottom cylindrical flange 370 connected by a cylindrical conduit 365 with a though hole 337 therein. Cylindrical conduit 365 includes an extension 368 extending downward towards an engagement flange 370 for extending into valve base 15.

Engagement flange 370 is sandwiched between a top surface of diaphragm 30 and a bottom surface of split ring 345, as shown in FIGs 1 1 and 12. An enlarged perspective view of split ring 345, including first and second halves 345a and 345b, is shown in FIG. 14. Split ring 345 inserted in above engagement flange 370 of bobbin 336. The split ring 345 serves dual purposes. Split ring 345 provides an additional magnetic radial path between the plunger and the frame and also functions as a spacer between the frame 50 and bobbin 336 to hold diaphragm 30 in place.

FIGs. 15 and 16 illustrate cross-sectional and exploded views of an additional embodiment of a valve assembly 510 with a modified adjustment screw 560, magnetic orifice piece 540 with a flat top end 542, and magnetic frame 550. The remaining components of pressure balancing valve assembly 510 are equivalent to the components described in connection with valve assembly 310, as shown in FIG. 11. However, it should be understood that alternate embodiments of bobbin and ring may be employed in valve assembly 510. Further, valve assembly 510 may be adapted to be an isolation valve similar to valve 410. Enlarged perspective and side views of the adjustment screw 560 are shown in FIGs. 17A and 17B. Adjustment screw includes shown as a generally cylindrical body with a top slit 562 to allow for tightening of the screw and includes a bottom end 564, a bottom flange 565 and extension 567 for engaging spring 55. A seal or gasket 568 may be positioned in a gap 570 between bottom end 564 and bottom flange 565, as shown in FIG. 15.

Perspective and side views of the frame 550 are shown in FIGS. 18A and 18B. The frame has a solid top surface that covers and contains magnetic orifice piece 540, which has a flat top end rather than an extension, as in previous embodiments. Magnetic frame 550 has a unitary generally C-shape construction. In particular, magnetic frame 550 includes a top section 590, a bottom section 591, and a side section 592. A notch 595 may also be formed within a lower surface of top section 590. Projections 596 bend at notch 595 perpendicularly from top section 590 to secure flux conductor or magnetic frame 550 to valve assembly 510. Bottom section 591 also includes an elongated opening 597 forming prongs 598 for engaging slots 118 in valve base 15.

FIG. 19 is a cross-sectional view of an additional embodiment of a valve assembly 610. FIGs 20a and 20b are side and cross- sectional views of a solenoid coil assembly 635 used in connection with valve assembly 610. Each of the remaining components of valve assembly 610 is consistent with the components described in connection with valve assembly 10. Bobbin 636 includes a top cylindrical flange 663 and a bottom cylindrical flange 664 connected by a cylindrical conduit 665 with a though hole 667 therein. Bottom cylindrical flange 664 includes an inward stepped portion 669 for engaging top annular opening 1 19 of valve base 15.

Cylindrical conduit 665 includes an extension 668 extending downward from bottom cylindrical flange 664 to a retaining flange 670 for extending into valve base 15 and retaining diaphragm 30 in place. Retaining flange 670 is sandwiched between a top surface of diaphragm 30 and a section of magnetic frame 50, as shown in FIGs 19.

FIG. 21 is an enlarged, cross-sectional view of valve assembly 610 showing that radial gap is maintained between magnetic frame 50 and plunger 20. An air gap 199 is also shown between plunger 20 and top pole piece 40.

Although the embodiments in the disclosure have been described primarily with reference to several specific embodiments, it will be apparent to those of ordinary skill in the art that the valve and the components thereof can be modified without departing from the spirit and scope of the invention as claimed.