Polymer Air & Vacuum Valve
Polymer agricultural air and vacuum valve for releasing air from irrigation lines and preventing vacuum and pipe collapse when they drain; single or combination type, threaded, 3/4 to 2 inch.
- Releases air as the line fills
- Lets air in on draining to prevent vacuum
- Single or combination type
- Polypropylene body, threaded
- 3/4 to 2 inch
Key Specifications
- Product code
- P122
- Material & grade
- PP
- Nominal size
- 3/4 to 2 inch
- Joint type
- Threaded
- Unit of sale
- Piece
- Applications
- Irrigation & agriculture
- Dimensional options
- 5 rows in the specification table
Why an irrigation line needs an air valve
When an irrigation line fills, the air inside the pipe needs a way out; air trapped at high points reduces flow and can cause water hammer. An air valve fitted at high points and at the head of each block releases this air automatically.
When the pump stops and the line drains, a vacuum can form inside the pipe, collapsing thin-walled pipe or drip tape or sucking mud into the drippers. The air valve then lets air into the pipe. The combination type does both and also slowly releases air that collects while the system runs.
Sizes and where to fit
Our rows cover polymer air valves in 3/4, 1, 1-1/4, 1-1/2 and 2 inch. The valve is threaded and is fitted on PE pipe with a threaded tee or a clamp saddle with a matching outlet.
Common locations are the high points of the main, after the pump and at the head of each irrigation block. The number and size of air valves are set by an irrigation designer from the line length and flow. In your enquiry give the size, type (single or combination) and quantity.
Inspecting and maintaining air valves
Inspect air valves at the start of the irrigation season: open the cover, clean the float and seal of scale and sand, and make sure the float moves freely. A stuck air valve either leaks or fails to release air.
Fit a small isolating valve below the air valve so you can open and clean it without draining the whole line. In cold regions, drain the valve before frost.
Polymer Air & Vacuum 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) |
|---|
| 3/4 |
| 1 |
| 1-1/4 |
| 1-1/2 |
| 2 |
Polymer Air & Vacuum Valve — FAQ
Where is an air valve fitted?
At high points of the main, after the pump and at the head of each block.
Single or combination air valve?
A combination valve releases air on filling, admits air on draining and releases air during operation.
Which sizes are supplied?
From 3/4 to 2 inch.
How is it fitted on PE pipe?
With a threaded tee or a clamp saddle with a matching outlet.
