APCO High Performance Combination Air Valve (ASU)



APCO High Performance Combination Air Valve (ASU)

Product Brochure



Unique, Multi-Stage Operation
The unique venting design provides varied and predictable air flow over a wide range of air release and air/vacuum conditions. A large diameter Air/Vacuum Disc provides high volume air flow for rapid venting during pipeline filling and allows high volumes of air to enter the pipeline during draining. During normal pipeline flow conditions, the dual-range air release design prevents air build up and resultant flow restrictions under changing conditions and through the full flow range.

Universal Valve Design, Wide Operating Range & Low Pressure Sealing Down to 2 psi
Venting design and technology allow application on an almost universal range of flow conditions with effective sealing and operation available in two pressure ranges: 2 psi to 150 psi or 2 psi to 300 psi for high pressure service.

Meets AWWA C-512 Performance Specifications
The ASU Combination Air Valve meets performance requirements of the AWWA C-512 standard “Air Valves for Water & Wastewater Service.”

All Stainless Steel Construction
The ASU Combination Air Valve is ideally suited to corrosive conditions with a 316 Stainless Steel body and float. Internal parts are corrosion resistant high strength stainless steel.

Light Weight, Low Profile Body Design
The compact design of the ASU Combination Air Valve allows installation in piping systems with limited space and in vaults with low ceiling heights. Fabricated ASU construction meets full pressure class ratings and minimizes weight for ease of installation and for retrofit replacement of other air valves.

Matched Inlet & Outlet Sizes
The equal size inlet and outlet area of the ASU valve fully meets the defined requirement of AWWA C-512 providing high capacity and a broad operating range. The ASU Combination air valve is available with flanged or threaded NPT inlet connections.

Float Shape Designed for Stability
The unique float shape reduces the ballistic effect of high-speed liquid flow into the valve, further adding to float stability. The float shaft is fully guided to provide smooth, long lasting operation.

No Troublesome Linkage
Unique disc air release venting concept eliminates linkages that can foul on dirty service applications.

Reliability Without Constant Maintenance
Clean interior design and the direct shaft mounted float eliminates troublesome linkages that can lead to frequent maintenance. The light weight, one-piece internal assembly can be easily lifted out of the valve body by the top cover. The shape of the upper valve body creates an air compression chamber to limit fluid level and solids interference. The funnel shaped lower body reduces solids buildup on sewage or other services where solids may interfere with operation, yet it still allows for maximum outflow and self-cleaning. For applications where standard practice calls for periodic maintenance, back flush ports are strategically located for ease of flushing with an optional back flush kit.

Larger Sizes, Higher Pressures
Valves to 300 psi are available in sizes 1″ through 4″ with 150 psi valve sizes available through 6” as standard. Contact DeZURIK for information and recommendations on other sizes and pressures

For Water/Wastewater or Industrial Service
All materials and seals are proven as long-life components for continuous duty service. Seals and all parts are suitable for use on water, wastewater or industrial media containing hydrocarbons, chemicals, solvents and volatiles. Recommendations available on application.


1-6” (25-150mm)

2 to 150 psi (14 to 1035 kPa) and 2 to 300 psi (14 to 2070 kPa)

316 Stainless Steel


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