Description
Watson McDaniel R-Series — Relief & Back Pressure Regulating Valve for Water, Oil & Other Liquids
The R-Series Back Pressure & Relief Valves are designed to maintain upstream pressure in various process applications. They automatically relieve excess pressure by diverting flow back to a tank or to a lower-pressure return line. These valves are ideal for pump bypass applications where constant pump discharge pressure must be maintained. They operate continuously to protect systems from overpressure.
Caution: Not to be used as an emergency or safety relief valve. NOT TO BE USED ON STEAM.
Product Overview
- Maintains constant upstream pressure by relieving excess pressure
- Suitable for Water, Oil, and Other Liquid applications
- Excellent for pump bypass applications
- Provides reliable pressure control under varying flow conditions
- Not designed for steam service
Material Specifications
- Body: Bronze
- Disc (1/2″ – 1-1/2″): Stainless Steel
- Disc (2″ – 3″): Bronze
Technical Specifications
- Available Sizes: 1/2″ – 3″
- Connection: Threaded, NPT
- Maximum Inlet Pressure: 300 PSIG
Options & Notes
- Factory Setting of Relief Pressure Option: Add desired factory-set pressure to the end of the model code.
- List Adder: $100.00
- Example Model Code with Set Pressure Option: R-12-N-2, Set at 50 PSIG
Available Models — R-Series Back Pressure / Relief Valves
| Size / Connection (NPT) | Model Code | Relief Pressure Range (PSIG) | Weight (lbs) |
|---|---|---|---|
| 1/2″ | R-12-N-4 | 1–6 | 1.5 |
| 1/2″ | R-12-N-3 | 5–35 | 1.5 |
| 1/2″ | R-12-N-2 | 25–100 | 1.5 |
| 1/2″ | R-12-N-1 | 75–300 | 1.5 |
| 3/4″ | R-13-N-4 | 1–6 | 2.0 |
| 3/4″ | R-13-N-3 | 5–35 | 2.5 |
| 3/4″ | R-13-N-2 | 25–100 | 2.5 |
| 3/4″ | R-13-N-1 | 75–300 | 3.3 |
| 1″ | R-14-N-4 | 1–6 | 3.3 |
| 1″ | R-14-N-3 | 5–35 | 3.3 |
| 1″ | R-14-N-2 | 25–100 | 3.3 |
| 1″ | R-14-N-1 | 75–300 | 3.3 |
| 1-1/4″ | R-15-N-4 | 1–6 | 4.5 |
| 1-1/4″ | R-15-N-3 | 5–35 | 4.5 |
| 1-1/4″ | R-15-N-2 | 25–100 | 4.5 |
| 1-1/4″ | R-15-N-1 | 75–300 | 4.5 |
| 1-1/2″ | R-16-N-4 | 1–6 | 6.3 |
| 1-1/2″ | R-16-N-3 | 5–35 | 6.3 |
| 1-1/2″ | R-16-N-2 | 25–100 | 6.3 |
| 1-1/2″ | R-16-N-1 | 75–300 | 6.3 |
| 2″ | R-17-N-4 | 1–6 | 10.5 |
| 2″ | R-17-N-3 | 5–35 | 10.5 |
| 2″ | R-17-N-2 | 25–100 | 10.5 |
| 2″ | R-17-N-1 | 75–300 | 10.5 |
| 3″ | R-19-N-4 | 1–6 | 25.0 |
| 3″ | R-19-N-3 | 5–35 | 25.0 |
| 3″ | R-19-N-2 | 25–100 | 25.0 |
| 3″ | R-19-N-1 | 75–300 | 25.0 |
Note: Pricing and configurations are subject to change. For exact technical details and ordering guidance, consult Watson McDaniel documentation or an authorized distributor.