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INNOVATION EXPERIENCESYNERGY COMMITMENTCREATIVITY

Air ValvesAir Valves

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Sources of Air

Sources of air in irrigation systems:

• Air trapped in the system during filling

• Water contains dissolved air

• Air drawn into the system by air valves and fittings under vacuum conditions

• Air intake when water comes from open sources

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Why Controlling the Air in Systems?

• High pressure surges

• Destructive vacuum conditions

• Pockets of accumulated air will impede hydraulic conductivity

• Accelerate corrosion of metal parts

• Reduce pump efficiency

• Inaccuracies in flow metering

• Accelerate cavitation damages

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Air Release & Vacuum Break Valves

Kinetic Air Valves

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Sample systemPump start-up

Pressurized air :• Risky• High pump resistance

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Risk for “air locks” (for low pressure systems)

Sample systemPump start-up

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Sample systemPump start-up

Kinetic air release valve :• Allows high air discharge flow:

– Large sized orifice• Closes drip tight when all air has vented and

the system filled with water.

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During system draining the internal pressure drops and may reach sub-

atmospheric levels.

Sample systemPipe drainage

This might cause the pipe to collapse!

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Sample systemPipe drainage

Kinetic vacuum break valve :• Allows high air intake flow:

– Large sized orifice• Prevents the risk for pipe collapse.

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Air Release & Vacuum Break Valves Types

AV-010 ¾”-2”DAV-P-K 1”-2”

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Air Release & Vacuum Break Valves

Combination Air Valves

Automatic Function Included

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During system operation (water under pressure) air is released and accumulates at

local peak points.

Sample systemPressurized air release

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Automatic Air Valves

• Small orifice

• Automatic release of entrapped air pockets from pressurized systems

SG-10 ½”-1”DAV-P-A ¾”-1”

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Combination Air Valves

• Features of the two previous models are incorporated in one single valve body, for safe pipeline filling and draining and for releasing air pockets during system operation

DG-10 ¾”-2”DAV-P-2”

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Combination Air Valves Principle of Operation

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Location of Air Valves

On rising from pumps, to release and admit air

At local peaks in the system

At transition points in hydraulic gradient

Before and after steep slopes

Every 500 m along pipeline sections of long uniform slope

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Thank You