Polymer Check Valve
Polymer check valve for stopping backflow on irrigation and drinking-water lines and protecting the pump; spring, ball or swing type, 1/2 to 4 inch.
- Water passes in one direction only
- Protects the pump from backflow
- Spring, ball or swing type
- Rust-free polypropylene body
- 1/2 to 4 inch
Key Specifications
- Product code
- P119
- Material & grade
- PP
- Nominal size
- 1/2 to 4 inch
- Unit of sale
- Piece
- Applications
- Irrigation & agriculture, Drinking water supply
- Dimensional options
- 9 rows in the specification table
What a polymer check valve does
A check valve lets water pass in one direction only. When the pump stops or line pressure drops, the valve closes and stops the water flowing back. This protects the pump from reverse spinning and keeps the upstream pipes from draining.
Our catalogue names three polymer check valve types: spring, ball and swing. The spring type works in any position and closes quickly; the swing type has a lower pressure loss and is mostly fitted on horizontal lines; the ball type jams less in water carrying particles.
Sizes and installation
Our rows cover polymer check valves in 1/2, 3/4, 1, 1-1/4, 1-1/2, 2, 2-1/2, 3 and 4 inch. The arrow on the body must point in the flow direction.
A check valve is usually fitted straight after the pump and before the isolating valve. In your enquiry give the size, type (spring, ball or swing), connection type and quantity. For sizes above 4 inch, see the cast iron check valve in the catalogue.
Check valves and water hammer
When a pump stops suddenly, the water column flows back, and if the check valve closes late, the water striking it causes a heavy shock known as water hammer. Spring check valves close quickly and reduce this shock, which is why they are preferred on pumping lines with a large lift.
Fit the check valve where it can be reached for inspection and cleaning. Coarse particles can stop the valve closing fully; a filter or strainer at the start of the line prevents this.
Polymer Check Valve — Technical Specifications
Wall thickness and weight are calculated from the standard series and are approximate; final values are confirmed in the quotation.
| Nominal Size (inch) |
|---|
| 1/2 |
| 3/4 |
| 1 |
| 1-1/4 |
| 1-1/2 |
| 2 |
| 2-1/2 |
| 3 |
| 4 |
Polymer Check Valve — FAQ
Where is a check valve fitted?
Usually straight after the pump, before the isolating valve.
Which type is best?
Spring for any position, swing for lower loss on horizontal lines, ball for water with particles.
Which sizes are supplied?
From 1/2 to 4 inch.
What suits larger sizes?
A cast iron swing or dual-plate check valve.
