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Model RVL-20 |
Low-Pressure Relief Valve |
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Features
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Applications
This safety relief valve can be used for relieving pressures and maintaining upstream line pressures to a specific set pressure. This diaphragm valve can also be used for bypassing fluids or gases. Only clean liquids and gases are recommended. When liquids contain debris or other solid matter that might cause improper operation of the diaphragm valve, a filter or strainer with a fine wire mesh should be installed before the inlet of the valve. Basket strainers or filters can be purchased from Stra-Val to solve this problem. This valve is used where accurate set pressures must be maintained. This is made possible because of the large diaphragm area used to sense the inlet pressure. Compared to higher-pressure piston models, this valve has a very low hysteresis between opening and closing pressures. See available orifice sizes and flow Cv below.
Options
Principle of Operation
This is a diaphragm and spring type relief valve where the spring constantly opposes the pressure acting against the diaphragm which seals off the inlet port from the outlet port at the valve seat. The desired relief or bypass pressure is achieved by compressing the spring until the spring force is adequate to balance the pressure force acting against the diaphragm. When the inlet pressure exceeds the set pressure, the diaphragm will open to relieve and bypass the excess pressure. The valve will operate in a vertical orientation as illustrated, horizontal, or any other orientation.
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| RVL-20 |
| 1. | Adjusting screw | Steel |
| 2. | Lock nut | Steel & SS |
| 3. | Spring chamber | Steel & SS |
| 4. | Spring pusher | Steel & SS |
| 5. | Spring | Steel & SS |
| 6. | Spring Carrier | Steel & SS |
| 7. | Diaphragm | Teflon/ Viton/ Buna |
| 8. | *Body | 303SS or 316SS |
*Body also available in PVC, Monel, Teflon, and Hastelloy (most sizes)
Dimensions
| Dimensions (inch) | Flow Data | |||||
| A | B | C | D | E | Orifice max | Cv |
|---|---|---|---|---|---|---|
| 1/4 | 2.38 | 1.00 | .44 | 5.56 | .125 | 0.28 |
| 3/8 | 2.88 | 1.25 | .50 | 5.59 | .375 | 2.52 |
| 1/2 | 2.88 | 1.25 | .63 | 5.88 | .500 | 2.98 |
| 3/4 | 2.88 | 1.25 | 1.25 | 6.69 | .438 | 2.98 |
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1 |
4.25 | 2.00 | 1.50 | 9.62 | .875 |
11.4 |
| 1.25 | 4.25 | 2.00 | 1.50 | 11.5 | 1.00 | 17.9 |
| 1.5 | 5 | 2.75 | 2.00 | 11.69 | 1.25 | 23.3 |
| 2 | 5 | 2.75 | 2.50 | 12.38 | 1.39 | 28.8 |
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: |
1/4" RVL20-02T | 3/8" RVL20-03T | 1/2" RVL20-05T | 3/4" RVL20-07T |
| 1" RVL20-10T | 1 1/4" RVL20-12T | 1 1/2" RVL20-15T | ||
To price or order, first select a size above.
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