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Model RVC-04 |
1/2" Npt ADJUSTABLE PRESSURE RELIEF VALVE |
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Features
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Applications
Use these valves for emergency relief where pressures must be relieved quickly to reduce damage that could result from overpressure in a system. Where the overpressure needs to be controlled more gradually ,such as in back pressure or pump bypass applications, use our Backpressure/Bypass valves which will reduce the probability of pressure spikes that often occur when relief valves are selected for pressure control applications.
This adjustable relief valve should only be used for non-corrosive fluids, or where the materials selected are compatible with the fluid and will not cause corrosive buildup that could keep the poppet from opening. When liquids contain debris or other solid matter that might cause internal clogging or improper operation of the stainless steel valve, a strainer with a fine wire mesh should be installed before the inlet of the valve. In-line strainer fittings or basket strainers can be purchased from Stra-Val to solve this problem. The seat diameter for this relief valve is 0.625 with a Cv of 5.5.
Avoid locating the valve where freezing can occur, and if unavoidable, take precautions to insulate or heat wrap valve and piping to keep from freezing.
These valves do not carry the Canadian CRN or ASME approval stamp and should not be applied where this requirement must be met. However, the valves generally meet or exceed ASME design criteria with wall thicknesses that are much heavier than the minimums required. For an additional charge, valves can be ordered with material certs and with a certified hydro-test certificate and other tests to meet special documentation and acceptance requirements.
Standard metal seated valves meet ANSI/FCI Class IV seat leakage standards (0.01% of rated valve capacity, not bubble tight).
For other sizes and higher pressures, see model RVC05
Options
Scroll down below to select the valve size, spring range, material options in the customized pricing and ordering section indicated by the red arrows. You have the ability to customize your valve choices by selecting the wetted and nonwetted materials, and choice of seat materials to suit your shutoff requirements, using the softer seats for improved shutoff, particularly for air or gas applications where they are available at the lower pressures. Once these selections are made a price quote can be generated and printed directly to your computer or immediately e-mailed to you.When ordering don't forget to state your desired relief set pressure if you expect the valve to relieve at only one pressure. This pressure will be engraved on the valve body. If the set pressure is not specified, the valve will be set at or below the stated spring range as selected for the order and no set pressure will be stamped on the nameplate.
Principle of Operation
This is a poppet and spring type relief valve where the spring constantly opposes the pressure acting against the poppet which seals off the inlet port from the outlet port at the valve seat. The desired set pressure or relief is achieved by compressing the spring until the spring force is adequate to balance the pressure force acting against the poppet. When the inlet pressure exceeds the set pressure, the poppet will open to relieve the excess pressure. Reseat pressure will depend on the piston seal material used. Typically, the Buna, Viton or Epdm seal will reseat within 5% of the set pressure and 10% with a PTFE seal that is harder.
These valves are not equipped with a manual lever release. However, manual override is accomplished by first unlocking the spring lock nut to the adjusting screw and backing it out enough to open the poppet to release pressure, and then repositioning it to its original preset locked condition without losing the original set pressure. This procedure is recommended periodically to flush the seat and to check for proper opening of the valve piston.
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| RVC-04 |
| 1. | Adjusting screw | Steel or SS | |
| 2. | Lock nut | Steel or SS | |
| 3. | * | Spring chamber | Aluminum, steel or SS |
| 4. | Spring pusher | Steel or SS | |
| 5. | Adjusting spring | Steel or SS | |
| 6. | Spring Carrier | Steel or SS | |
| 7. | † | Poppet | 303 SS, brass, or PTFE |
| 8. | ‡ | Piston Seal | Buna, EPDM, Viton PTFE |
| 9. | † | Body | Brass only |
* Aluminum used for low pressures
† Stainless steel standard or when required at higher temperatures
‡ Alternate elastomers available
Dimensions
| Size | A | B | C | D |
|---|---|---|---|---|
| 1/2 | 1-1/2 | 1-3/8 | 1-1/4 | 6 |
Note: Dimensions are approximate and are subject to change without notice. Request certified dimensions before final product installation.
To show prices: Click on a size: |
1/2" RVC04-05T | |||
To price or order, first select a size above.
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