초록 ▼

The pressure limiting valve has a low pressure gauge configured to measure the operability of a backflow prevention device having a line pressure relatively higher than the maximum PSI rating of the low pressure gauge. The valve body has an inlet statically coupled to a pressurized fluid source and

The pressure limiting valve has a low pressure gauge configured to measure the operability of a backflow prevention device having a line pressure relatively higher than the maximum PSI rating of the low pressure gauge. The valve body has an inlet statically coupled to a pressurized fluid source and an outlet coupled to the low pressure gauge. Upper and lower chambers fluidly coupled via a conduit are formed from an interior portion of the valve body and generally separated by a flexible diaphragm. A spring actuable via movement of the flexible diaphragm in response to pressure changes in the valve body biases a closure seat in an open position relative to the outlet when the valve body is not under pressure, and compresses under pressure to permit the closure seat to seal the outlet when pressure in the valve body reaches a maximum PSI rating of the low pressure gauge.

대표청구항 ▼

1. A pressure limiting valve having a first pressure gauge configured to measure the operability of a backflow preventer having a line pressure relatively higher than a maximum PSI rating of the first pressure gauge, the valve comprising: a valve body having an inlet configured to statically couple

1. A pressure limiting valve having a first pressure gauge configured to measure the operability of a backflow preventer having a line pressure relatively higher than a maximum PSI rating of the first pressure gauge, the valve comprising: a valve body having an inlet configured to statically couple to the backflow preventer and an outlet configured to couple to the first pressure gauge and a second pressure gauge;an upper and lower chamber formed from an interior portion of the valve body, the chambers being generally separated by a diaphragm;a conduit fluidly coupling the upper and lower chambers;a spring actuable via movement of the diaphragm in response to pressure changes in the valve body, wherein the spring generally biases a closure disc in an open position relative to the outlet when the valve body is not under pressure, and compresses under pressure to permit the closure disc to seal the outlet when pressure in the valve body approximately reaches the maximum PSI rating of the first pressure gauge, thereby limiting the maximum pressure deliverable to the first pressure gauge; anda fluid control valve to selectively control fluid flow from the lower chamber to a drain. 2. The valve of claim 1, including a diaphragm retainer disposed across at least a portion of a planar surface of the diaphragm and influenced by movement of the spring. 3. The valve of claim 1, wherein the spring comprises a pair of opposing springs disposed across opposite portions of the diaphragm in respective upper and lower chambers, the first spring biasing the closure disc in an open position relative to the outlet and the second spring positioned to oppose open movement of the closure disc by the first spring. 4. The valve of claim 1, including a tensioner coupled to the spring for adjusting the pressure deliverable to the first pressure gauge. 5. The valve of claim 1, wherein the line pressure comprises a hydraulic fluid source. 6. The valve of claim 1, including a vent formed from a cap coupled to the valve body, the vent being fluidly coupled to the upper chamber. 7. The valve of claim 1, wherein the diaphragm comprises a flexible rubber diaphragm. 8. The valve of claim 1, wherein the fluid control valve comprises a needle valve having a displaceable stem to selectively control fluid flow from the lower chamber to the drain. 9. The valve of claim 1, including a relief valve in fluid communication with the first pressure gauge and having a release point approximately the same as the maximum PSI rating of the first pressure gauge. 10. The valve of claim 1, wherein the valve body selectively mounts to a portable backboard. 11. The valve of claim 1, including a seat positioned near the outlet and tapering downwardly away from the diaphragm to permit deflection of the closure disc thereover. 12. The valve of claim 11, including a stem biased between the spring and a diaphragm retainer and extending into a vertical passageway at least partially circumscribed by the seat. 13. The valve of claim 1, including a high second pressure gauge in fluid communication with the inlet for measuring the line pressure. 14. The valve of claim 13, wherein the valve body includes a pair of oppositely extending arms, the first arm for carrying relatively high pressure fluid to the second pressure gauge, and the second arm for carrying relatively low pressure fluid through the outlet to the first pressure gauge. 15. A pressure limiting valve having a first pressure gauge configured to measure the operability of a backflow preventer having a line pressure relatively higher than a maximum PSI rating of the first pressure gauge, the valve comprising: a valve body having an inlet configured to statically couple to the backflow preventer and an outlet configured to couple to the first pressure gauge and a second pressure gauge;an upper and lower chamber formed from an interior portion of the valve body and separated by a diaphragm;a conduit fluidly coupling the upper and lower chambers;a pair of opposing springs disposed across opposite portions of the flexible diaphragm in respective upper and lower chambers and actuable via movement of the flexible diaphragm in response to pressure changes in the valve body, wherein when the valve body is not under pressure the first spring biases a closure disc to an open position relative to the outlet and the second spring opposes such open movement of the closure disc by the first spring, andwherein when the valve is under pressure approximately equal to the maximum PSI rating of the first pressure gauge, the first spring compresses to permit the closure disc to seal the outlet, thereby limiting the maximum pressure deliverable to the first pressure gauge;a seat positioned near the outlet and tapering downwardly away from the diaphragm to permit deflection of the closure disc thereover;a diaphragm retainer disposed across at least a portion of a planar surface of the diaphragm and influenced by movement of the first and second springs; anda fluid control valve to selectively control fluid flow from the lower chamber to a drain. 16. The valve of claim 15, including a stem biased between the first spring and the diaphragm retainer and extending into a vertical passageway at least partially circumscribed by the seat. 17. The valve of claim 15, wherein the valve body includes a pair of oppositely extending arms, the first arm for carrying relatively high pressure fluid to the second pressure gauge from the line pressure comprising a hydraulic fluid source, and the second arm for carrying relatively low pressure fluid through the outlet to the first pressure gauge. 18. The valve of claim 15, including a tensioner coupled to the first spring for adjusting the maximum pressure deliverable to the first pressure gauge and a vent formed from the valve body and fluidly coupled to the upper chamber. 19. The valve of claim 15, wherein the fluid control valve comprises a needle valve having a movable stem to selectively control fluid flow from the lower chamber to the drain. 20. The valve of claim 15, including a relief valve fluidly coupled to the first pressure gauge and having a release point approximately the same as the maximum PSI rating of the first pressure gauge. 21. The valve of claim 15, including a second pressure gauge coupled to the inlet for measuring the line pressure. 22. A pressure limiting valve, comprising: a valve body having an inlet configured to statically couple to a hydraulic fluid source;an upper and lower chamber formed from an interior portion of the valve body, the chambers being separated by a diaphragm;a conduit fluidly coupling the upper and lower chambers;a spring actuable via movement of the flexible diaphragm in response to pressure changes in the valve body, the spring positioned to bias a closure disc in an open position relative to an outlet when the valve body is not under pressure, and configured to compress under pressure to permit the closure disc to seal the outlet when pressure in the valve body reaches a closure pressure, thereby limiting the maximum pressure deliverable to the outlet; anda fluid control valve to selectively control fluid flow from the lower chamber to a drain. 23. The valve of claim 22, including a diaphragm retainer disposed across at least a portion of a planar surface of the diaphragm and influenced by movement of the spring. 24. The valve of claim 22, wherein the spring comprises a pair of opposing springs disposed across opposite portions of the flexible diaphragm in respective upper and lower chambers, the first spring biasing the closure disc in an open position relative to the outlet and the second spring positioned to oppose open movement of the closure disc by the first spring. 25. The valve of claim 22, including a tensioner coupled to the spring for adjusting the pressure deliverable to the outlet and a vent formed from a cap coupled to the valve body. 26. The valve of claim 22, wherein the diaphragm comprises a flexible rubber diaphragm. 27. The valve of claim 22, including a seat positioned near the outlet and tapering downwardly away from the diaphragm to permit deflection of the closure disc thereover. 28. The valve of claim 27, including a stem biased between the spring and a diaphragm retainer and extending into a vertical passageway at least partially circumscribed by the seat.