Air Release Valve • Series ARV

Product Education Course

3 ways air enters a piping system:

1. It is there to begin with, unless the piping system is assembled in a vacuum.

2. It enters mechanically, drawn through pumps, seals, valves, fittings etc. while the system is operating.

3. It enters as part of the liquid, then outgasses from the liquid.

How much air is found in the average piping system?

• Entrained Air represents 2% of the average municipal water supply.

• When this outgasses, it joins existing air at system high points.

• In a 100 foot piping system, this represents a 2 foot slug of air…in 1000 ft., it adds up to a 20 ft slug of air…regardless of pipe diameter.

What does air do in a piping system?

1. Liquid flow causes it to move along, until it collects at high points.

2. As air collects, it reduces the area available for flow. These flow restrictions reduce the efficiency and performance of the piping system.

3. The air pocket grows, velocity increases...

4. Velocity & pressure build until the air pocket is swept downstream at dangerous speed...

End Result of Air in a Piping System:

• Rapid Venting of Air

• Water Hammer

• Pressure Surges

• System Damage

Common remedies…• Connect a long run of vertical pipe to a ball valve

on a tee. Open the valve at system start-up to allow air to escape, then close it as the pipe fills.

• Install an Air/Vacuum valve on the tank.

Drawbacks…• The ball valve is not automatic; if someone forgets to

open or close the valve, the results can be disastrous.• A tank mounted valve is only effective for air in the

tank – won’t purge air trapped elsewhere in the system.

Ball-type Air Release Valves are Ineffective…

• Competitive air release valves are based on a floating hollow plastic ball.

• Plast-O-Matic engineers worked on a similar product, but extensive testing proved that the floating ball concept is inherently flawed.

• Ball floats too easily – too much air remains trapped• Even brief exposure to pressure causes the ball to

become out-of-round and difficult to seal.• Prolonged exposure to pressure makes it extremely out-

of-round…impossible to seal

A Real Solution to the Problem…• The Plast-O-Matic Series ARV Air Release Valve:

A normally-open valve that allows air to escape• Self-guided poppet closes when liquid rises.

How it works…

How it works…

Where to use it… High points

Tanks

Specifications:

• ½", ¾" & 1" NPT connections• NPT outlet – permits corrosive vapors and

emissions to be piped safely away• PVC or CPVC body materials• Viton FKM or EPDM seals• No metal parts• Liquid must have specific gravity of .9 or

higher.

Performance:

• Closes at 0 psi as long as liquid is present.

• Bubble tight seal at 10 psi (EPDM) or 15-20 psi (Viton FKM)

• Max pressure rating 150 psi @ 75º F

• Max Air Flow Rate 8 SCFM

• Max liquid flow rate 60 GPM (use additional units for higher flow rates)

Advantages vs. Competition:

1. Self-guided poppet does not become egg-shaped, such as floating ball designs.

2. NPT outlet simplifies piping for applications with potentially hazardous emissions.

3. Union nut enables valve to be opened and inspected/cleaned easily – no tools required.

4. Density of poppet enables it to stay open longer than floating ball – more air is expelled prior to closing.

Series ARV • Air Release Valve