Description

The air vent valve is one of the most important components in any pressurized irrigation system. It automatically removes trapped air from pipelines, prevents air locks, protects against water hammer, and significantly extends the service life of pipes, fittings and pumps. Vispar is one of Iran’s most trusted manufacturers of high-quality air vent valves and other irrigation equipment.

Air Vent Valve

The Vispar Air Vent Valve is a fully polymeric automatic valve designed to release trapped air during filling and normal operation, while also allowing air intake when the pipeline is drained (vacuum relief). Proper use of these valves eliminates:

Air pockets that disrupt flow
Water hammer and pipe bursts
Cavitation damage to pumps and control valves
Reduced pump efficiency and uneven irrigation

Technical Specifications – Vispar Air Vent Valve

Sizes: 1″ and 2″ (threaded)
Maximum working pressure: 10 bar
Body material: High-strength polypropylene (PP) – 100 % corrosion-proof
Seals: EPDM or NBR
Recommended maximum pipe diameter: up to 250 mm (10″) → use 2″ valve; smaller lines → use 1″ valve
Fully automatic operation – no electricity or manual intervention required

Applications

Drip irrigation mainlines and sub-mains
Sprinkler and classic rainfall irrigation systems
Any pressurized water supply or filtration system
Installed at high points, long horizontal runs, and before/after pumps and valves

How It Works

During filling: Air inside the pipe pushes the float down → the vent stays open and rapidly expels large volumes of air
Normal operation: Water pressure lifts the float → the valve seals tightly, preventing water loss
During draining or pressure drop: The float drops → the moment negative pressure occurs → air rushes in and prevents vacuum formation and pipe collapse