WO2010093852A1

WO2010093852A1 - Pilot protector for valve

Info

Publication number: WO2010093852A1
Application number: PCT/US2010/023996
Authority: WO
Inventors: Paul Szymaszek
Original assignee: Parker Hannifin Corporation
Priority date: 2009-02-16
Filing date: 2010-02-12
Publication date: 2010-08-19

Abstract

A pilot protector (39) is presented for use with a pilot operated solenoid valve such as the type of valve used in refrigeration systems. The pilot protector is a tube extending radially inward from the base of the pilot bore (37) formed in the inlet passageway (26) of the housing. The pilot protector helps prevent contamination of the valve by preventing dirt that travels at lower velocity along the inlet passageway from entering the pilot bore.

Description

PILOT PROTECTOR FOR VALVE

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of the filing date of U.S. Provisional Patent Application Serial No. 61/152,800, filed February 16, 2009, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] The present invention relates, in general, to a globe valve (solenoid valve) such as the type used in refrigeration applications, and in particular to a pilot protector used to help prevent contamination of the valve.

BACKGROUND

[0003] Many valves used in industrial refrigeration are pilot operated. Pilot operated valves function by applying pressure to a piston in the valve which either pushes the valve open or shut. As long as the pressure is maintained on the piston the valve stays in the open or shut position. The source of the pilot gas or liquid can be either from the line in which the valve is installed, or an external source. The supply of the pilot gas or liquid is typically controlled by a smaller solenoid valve which is either in an on or off state, allowing pilot flow to the piston or not. [0004] A prior art pilot operated refrigerant solenoid valve 110 is shown in FIG. 1 in a closed position with the solenoid coil 152 de-energized. The valve 110 comprises a valve body housing 120 having an inlet passageway 126, an outlet passageway 128 and a through port or valve seat 130, providing a fluid passageway between the inlet passageway 126 and the outlet passageway 128. The valve assembly 110 also comprises a piston 140 reciprocable within a bore 135 in the valve body housing 120 which includes a valve plug member 144 being adapted to sealingly mate with the valve seat 130 to open and close the valve 110. A pilot bore 137 is shown extending through the housing 120 and connecting with passageway 133 and passageway 131 of an adapter plate 150 which is attached to the open bore end of the housing 120. The solenoid 152 operable to fluidly connect and disconnect the portion of the bore 135 above the piston 140 to the pilot bore 137 of the valve housing 120. [0005] In operation, the valve 110 is opened by energizing the solenoid 152 which opens the passageway formed by pilot passageway 137, passageway 133 and passageway 131. The high pressure fluid flow through the pilot port passageway 137 to the top of the piston 140 forces the piston 140 and the plug 144 downward, opening the valve 110.

[0006] De-energizing the solenoid 152 closes the passageway between the top of the piston 140 and the valve inlet passageway 126. The pressurized fluid trapped above the piston 140 is able to pass through a bleed hole 142 in the piston to the valve outlet passageway 128. As the pressure bleeds away, the spring 148 pushes the plug 144 back to seal against the valve seat 130, closing the valve 110.

[0007] Contaminants in refrigeration systems are often the root cause for valves failing to function. The flow path for the pilot is from the valve inlet passageway and is located at the outer wall of the valve body. The dirt traveling along the outside of the pipe at low velocity goes through this opening into the pilot mechanism. These contaminants create problems with the proper functioning of the valve. Many different solutions exist today which primarily involve filtering the pilot flow to prevent contaminants from entering the pilot mechanisms.

SUMMARY

[0008] At least one embodiment of the invention provides a pilot operated valve assembly comprising: a valve housing having an inlet passageway and a pilot bore formed through a wall of the inlet passageway and extending through a portion of the housing; a pilot protector member extending from the wall of the inlet passageway; wherein an inlet end of the pilot protector has an opening that is positioned such that the opening is shielded from direct fluid flow coming into the valve housing in a direction parallel to a centerline of the inlet passageway. [0009] At least one embodiment of the invention provides a pilot operated valve assembly comprising: a valve housing including an inlet port having an inlet passageway and an outlet port having an outlet passageway separated by an aperture forming a valve port, the valve housing having a cylindrical bore; a piston reciprocally moveable within the bore and coupled to a valve member operable to open and close the valve port; a pilot bore extending through the housing and fluidly connecting the inlet passageway to the open bore end of the housing; an adapter plate attached to an open bore end of the housing, the plate including a solenoid operable to fluidly connect and disconnect a chamber above the piston to the pilot bore of the valve housing; and a pilot protector tube extending generally radially inward from a wall of the inlet passageway, the pilot protector tube having an opening at an inlet end of the pilot protector tube, the opening shielded by the pilot protector tube from the flow direction of fluid through the inlet passageway.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Embodiments of this invention will now be described in further detail with reference to the accompanying drawings, in which:

[0011] FIG. 1 is a cross-sectional view of a prior art pilot operated solenoid valve;

[0012] FIG. 2 is a cross-sectional view of a pilot operated solenoid valve having an embodiment of a pilot protector in accordance with the present invention;

[0013] FIG. 3 is a partial cross-sectional detail view of the pilot protector within the inlet passageway of the valve as shown in FIG. 2; [0014] FIG. 4 is a partial cross-sectional view of a second embodiment of a pilot protector within the inlet passageway of the valve; and [0015] FIG. 5 is a partial cross-sectional view of another embodiment of a pilot protector within the inlet passageway of the valve.

DETAILED DESCRIPTION

[0016] An embodiment of the present invention is shown in FIG. 1 as a pilot protected valve assembly 10. The valve assembly 10 comprises a valve body housing 20 having an inlet 22, an outlet 24, an inlet passageway 26, an outlet passageway 28 and a through port or valve seat 30, providing a fluid passageway between the inlet passageway 26 and the outlet passageway 28. The valve assembly 10 also comprises a piston 40 reciprocable within a bore 35 in the valve body housing 20 which includes a valve plug member 44 being adapted to sealingly mate with the valve seat 30 to open and close the valve 10. A pilot bore 37 is shown extending through the housing 20 and connecting with passageway 33 and passageway 31 of an adapter plate 50 which is attached to the open bore end of the housing 20. The solenoid 52 is operable to fluidly connect and disconnect the portion of the bore 35 above the piston 40 to the pilot bore 37 of the valve housing 20 by closing the fluid connection between passageway 31 and passageway 33.

[0017] In accordance with the present invention, a pilot protector 39 is shown extending generally radially inward from a wall of the inlet passageway 26 at the pilot bore 37, the pilot protector 39 having an opening 81 that is shielded by the pilot protector from the flow direction 17 of fluid through the inlet passageway 26. Flow direction 17 is indicated by the arrow in the inlet passageway as a direction parallel to the centerline of the inlet passageway. The pilot protector 39 prevents the dirt traveling along the wall of the inlet passageway 26 at low velocity from entering the pilot bore 37 and contaminating operation of the pilot mechanism.

[0018] In one embodiment of the invention, the pilot protector 39 is a tube extending into the valve inlet flow stream 17 which is at a higher velocity than the flow at the walls of the inlet passageway. Dirt and other contaminants are much less likely to be in the higher velocity central flow of the fluid as they are pushed to the slower moving fluid adjacent the walls of the inlet passageway 26. In the embodiment shown in FIG. 2 and in detail in FIG. 3, the pilot protector 39' is formed by a tube having an end cut at an angle θ, shown at about 45 degrees and preferably between 15-75 degrees, but not limited as to the particular angle shown, and aligned in such a manner that the opening 81 of the tube 39 is not directly exposed to the flow direction and can not catch any dirt particles that may not have been pushed to the slower moving fluid adjacent the walls of the inlet passageway. The angled cut also reduces any venturi effect that could be present with a 90 degree cut. In FIG. 4, the pilot protector is cut at 90 degrees; however the extension is curved from the flow stream 17 such that the opening 81' is still shielded from the direct flow. Another embodiment is shown in FIG. 5 wherein the end of the pilot protector 39" is a closed end and the opening 81" is formed on the downstream side of the extension 39" at a distance spaced from the end and at a distance spaced from the wall of the inlet passageway 26 such that the opening 81" is shielded from the direct flow of the flow stream 17.

[0019] It is noted that there are other types of pilot operated valves that vary from design shown herein and that the pilot protector can be used in any pilot operated valve. Although the principles, embodiments and operation of the present invention have been described in detail herein, this is not to be construed as being limited to the particular illustrative forms disclosed. They will thus become apparent to those skilled in the art that various modifications of the embodiments herein can be made without departing from the spirit or scope of the invention.

Claims

1 , A pilot operated valve assembly comprising: a valve housing having an inlet passageway and a pilot bore formed through a wall of the inlet passageway and extending through a portion of the housing; a pilot protector member extending generally radially inward from the wall of the inlet passageway; wherein an inlet end of the pilot protector has an opening that is positioned such that the opening is shielded from direct fluid flow coming into the valve housing in a direction parallel to a centerline of the inlet passageway.

2. The pilot operated valve assembly of claim 1 , wherein the pilot protector is at least partially curved in the direction of fluid flow in the inlet passageway.

3. The pilot operated valve assembly of claim 1 , wherein the opening of the inlet end of the pilot protector is formed at an angle with respect to a longitudinal axial centerline of the pilot protector.

4. The pilot operated valve assembly of claim 3, wherein the angle is between 15 and 75 degrees inclusive.

5. The pilot operated valve assembly of claim 1 , wherein the opening of the pilot protector is spaced from the radial inward end of the pilot protector.

6. A pilot operated valve assembly comprising: a valve housing including an inlet port having an inlet passageway and an outlet port having an outlet passageway separated by an aperture forming a valve port, the valve housing having a cylindrical bore; a piston reciprocally moveable within the bore and coupled to a valve member operable to open and close the valve port; a pilot bore extending through the housing and fluidly connecting the inlet passageway to the open bore end of the housing; an adapter plate attached to an open bore end of the housing, the plate including a solenoid operable to fluidly connect and disconnect a chamber above the piston to the pilot bore of the valve housing; and a pilot protector tube extending generally radially inward from a wall of the inlet passageway, the pilot protector tube having an opening at an inlet end of the pilot protector tube, the opening shielded by the pilot protector tube from the flow direction of fluid through the inlet passageway.

7. The pilot operated valve assembly of claim 6, wherein the pilot protector tube is at least partially curved in the direction of fluid flow in the inlet passageway.

8. The pilot operated valve assembly of claim 6, wherein the inlet end of the pilot protector tube is formed at an angle with respect to a longitudinal axial centerline of the pilot protector tube.

9. The pilot operated valve assembly of claim 8, wherein the angle is between 15 and 75 degrees inclusive.

10. The pilot operated valve assembly of claim 1 , wherein the opening of the pilot protector tube is spaced from the radial inward end of the pilot protector tube.

11. A method of preventing pilot contamination in a pilot operated solenoid valve comprising the steps of: providing a pilot operated solenoid valve having a pilot bore formed through a wall of an inlet passageway of a housing of the pilot operated solenoid valve; attaching a pilot protector tube to the pilot bore such that an opening of the pilot protector is positioned near the axial centerline of the inlet passageway and such that the opening of the pilot protector is shielded from direct fluid flow coming into the valve housing in a direction parallel to the axial centerline of the inlet passageway.