1/2" Watson McDaniel 10691-12-N-3-E Back Pressure & Relief Valves (For Water/Liquids), Heavy-Duty Bronze Valve Body, 5 - 35 PSIG, EPDM Standard, NPT
Technical Specifications
General
| Model | 10691 Series |
|---|---|
| Service | Liquids |
| Size | 1/2" |
| Body | Bronze |
| Part Number | 10691-12-N-3-E |
| Brand | Watson McDaniel |
| Manufacturer Part # | 10691-12-N-3-E |
| Country of Origin | Made in the United States |
Materials & Construction
| Seat Material | Bronze |
|---|---|
| Disc Material | EPDM* |
Performance
| Max Inlet Pressure | 300 PSIG |
|---|---|
| Design Pressure/Temperature Rating - PMA/TMA | NPT - 300 PSIG @ 180°F |
Connections
| Connections | NPT |
|---|
Overview
Watson McDaniel 10691-12-N-3-E Back Pressure & Relief Valves, 5 - 35 PSIG (EPDM Standard) For Water/Liquids (1/2" NPT)
Features:
- 10691 Series has EPDM Seat for tight shut-off (1/2” - 1”)
- Four Springs – Easily interchanged to cover pressures from 1 to 300 PSIG.
- Heavy-Duty Bronze Valve Body
Options & Features (See Specification Sheet For Full List):
10691 Series Back Pressure & Relief Valves (For Water/Liquids)
Water, Liquids: The 10691 Series are economically-priced Back Pressure Relief Valves for Liquid service. Relief Valves/Back Pressure Valves are used to maintain a specific back pressure or to protect systems from an over-pressure condition. Also used for pump protection.
The 10691-Series Back Pressure & Relief Valves relieve upstream pressure in a variety of processes. 10691-Series has a soft elastomeric disc for tight shut-off. This valve automatically maintain desired maximum pressure in a vessel or system by relieving excess pressure into lower pressure re turn line or to atmosphere. Ideally suited for use as pump bypass control valve by maintaining constant pump discharge pressures. Used as a continuously operating valve or for protection against intermittent over pressure conditions.
The 10691-Series Back Pressure Relief Valves are used in the following applications:
- Water pump bypass for irrigation, sprinkler systems on golf courses, fountains and fire protection systems.
- Fuel oil pump bypass on commercial systems or large residential systems.
Important Note: NOT TO BE USED ON STEAM.
How It Works
The Relief Valve is actuated by the system pressure on the inlet side of the valve. Valve loading is provided by a spring. The adjustment is done by removing the cap and rotating the screw clockwise or counter-clockwise. Spring load balances against the opening force of the upstream (or relief) pressure. Valve will open at the slightest increase in pressure above the spring set point, and will close when the excess pressure has been relieved.
The higher the system pressure is above the relief set point pressure, the more flow the valve will pass. It is therefore typical to specify the maximum capacity of a back pressure relief valve at 10% and 20% over set pressure.
Pressure Adjustments
To adjust set pressure of valve, remove top cap, loosen lock nut and adjust pressure by rotating adjustment screw. Rotating the screw clockwise increases the compression on the spring thereby increasing the set pressure. Rotating the screw counterclockwise lowers the set pressure. Tighten the lock nut and replace top cap and gasket.
Selection / Sizing / Capacities
The Relief Valve remains closed until the Set-Pressure is reached. When the Set-Pressure is met or exceeded, the spring will compress, allowing the valve to open and flow to occur. It is standard practice to publish flow values at 10% and 20% over the Set-Pressure.
Example:
- A 1” valve set at 50 PSIG will pass 3.1 GPM if the system pressure exceeds the set point by 20%.
The 10691 Series Relief Valve water capacities at inlet pressures of 10% and 20% over Set-Pressure.
