API · ASME · DIN · EN standard industrial valves
Air Release Valves
Hydraulic valves venting trapped air at pipeline high points and admitting air during draining to prevent vacuum and surge.
Last updated: 2026-11
Family specifications
| designs | Single Orifice, Double Orifice, Double Orifice Kinetic, Combination |
|---|---|
| body materials | WCB (ASTM A216), CF8, CF8M (ASTM A351), F316, F316L (ASTM A182), F51/2205 duplex (ASTM A182), F53, F55/2507 super duplex (ASTM A182), C95400, C95800 aluminium bronze (ASTM B148), nickel-copper alloy 400, nickel-chromium alloy 625 (ASTM B564) |
| design focus | Air discharge and admission capacity, float response speed and stability, tight sealing under system pressure, fouling resistance, structural integrity under surge |
| functions | Continuous air release at high points, Air admission during draining (vacuum breaking), Rapid air discharge during filling (kinetic) |
| size range | 1" to 20" (single body 1"-8", dual body 10"-20") |
| design standards | AWWA C512 |
| pressure class | PN10, PN16, Class 125 |
| temperature range | -20 to 180°C (KXC single release, water/oil/gas) |
| awwa c512 types | Air Release, Air/Vacuum, Combination |
| air release sizing rule | Dissolved air approx. 2% by volume; venting capacity q = Q (GPM) x 0.13 cu ft/gal x 0.02 (SCFM) |
| air vacuum sizing differential | 2 psi (14 kPa) standard; up to 5 psi (35 kPa) with slow-closing device |
| vacuum sizing criterion | Admit air at the lower of 5 psi differential or pipe collapse pressure |
| awwa m51 location schedule | High points: combination; long horizontal runs, descents, ascents: valves at 1250-2500 ft (380-760 m) intervals; flow meters: air release upstream; well/vertical turbine pumps: air/vacuum with slow-closing or throttling device |
| float and trim | T316 stainless steel floats, stainless steel 316 internal trim, resilient seating, full pipe size inlets/outlets |
| certifications | NSF 372 Certified Lead-Free, NSF 61 Certified for Drinking Water, Meets AWWA C512 |
| anti shock design | Anti-shock air valves (e.g. Vent-O-Mat RBX) are designed so air-discharge closure limits the transient pressure rise to 1.5x rated working pressure, controlling slam/surge on fast-filling lines |
| dynamic floatless design | Floatless dynamic combination air valves (A.R.I. D-070) replace floats with a rolling diaphragm and a small pilot orifice: air discharges through the large orifice, then system pressure acting on the pilot lowers the rolling-diaphragm assembly to seal it — a design aimed at resisting fouling in wastewater service |
| air valve maintenance interval | A.R.I. D-070 IOM: the valve should be maintained at least once a year, in accordance with the quality and composition of the fluid in the system; seals and diaphragm inspected for cracks and tears |
| installation air trap sizing | A.R.I. D-070 IOM installation practice: air-trap riser diameter = pipeline diameter up to 300mm, 60% of diameter up to 1500mm, 35% above; riser up to 150mm; air trap at least 150mm; a manual isolation valve is required under the valve inlet |
| compressed gas hazard | Air release valves — especially wastewater models — may contain a significant volume of compressed gas with accumulated energy; depressurize before servicing |
| working pressure excludes surge | Manufacturer IOM note: the stated maximum working pressure does not include pressure changes caused by water hammer and surge effects — surge analysis is a separate duty check |
| rbx positioning schedule | Vent-O-Mat RBX installation schedule: air valves at system summits and high points, along long horizontal runs and at significant grade changes, downstream of pump discharge / after check valves, and at blank ends; single-chamber anti-shock combination design (PN16/25/40, DN25-200) |
| factory testing | Vent-O-Mat RBX factory tests include hydrostatic pressure tests at 1.5x rated pressure, low-pressure sealing checks, and float/mechanism drop testing on a sampled basis |
Scope & source notes
| air valve type taxonomy | Vendor catalog tree lists four designs (Single Orifice / Double Orifice / Double Orifice Kinetic / Combination), while AWWA C512-15 standardizes three basic types: Air Release, Air/Vacuum, Combination. 'Double Orifice Kinetic' is vendor vocabulary corresponding to kinetic/air-release designs under the standard taxonomy; reconcile on next taxonomy pass. |
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Ordering & documentation
Documents
Ask for the documentation set with the inquiry — typical items (material certificates, test reports to the listed inspection standard, dimensional drawings) are confirmed and supplied with the quotation.
Quotation
Send the medium, temperature, pressure, size and connection for a quotation-ready inquiry. Lead time, MOQ and price are confirmed at quotation, together with the documents to be supplied with the order.
Sample & supply
Supply terms, order quantities and lead time are agreed per order — state the destination country and required schedule with the inquiry.
Storage & shipping
Store valves with seats and seals protected from UV, ozone and deformation, and keep end-face protectors on until installation; storage limits and shipping arrangements for the selected materials are confirmed at quotation.
Frequently asked questions
What standards govern the design and testing of air release valves?
The published specification for this family lists AWWA C512 as the design standards.
What sizes and pressure ratings are available for air release valves?
The published size range is 1" to 20" (single body 1"-8", dual body 10"-20"), and the published pressure ratings are PN10, PN16, Class 125. Availability of a specific size and rating is confirmed at quotation.
What materials are air release valves available in?
The published specification lists body materials: WCB (ASTM A216), CF8, CF8M (ASTM A351), F316, F316L (ASTM A182), F51/2205 duplex (ASTM A182), F53, F55/2507 super duplex (ASTM A182), C95400, C95800 aluminium bronze (ASTM B148), nickel-copper alloy 400, nickel-chromium alloy 625 (ASTM B564). Material availability for a specific size and rating is confirmed at quotation.
What working temperature range do air release valves cover?
The published working temperature range is -20 to 180°C (KXC single release, water/oil/gas). For a medium at the edge of the range, confirm the suitability of the selected seat and body materials at quotation.
What should a quotation inquiry for air release valves include?
The governing standard and class, nominal size, body and seat materials, the service medium with temperature, and the destination — anything missing is confirmed during quotation.
Types in this family
Type
Single Orifice Air Valves
Single orifice air valves vent accumulated air from liquid lines through one small orifice: a stainless float drops as air gathers in the chamber, opening the s
View specifications →Type
Double Orifice Air Valves
Double orifice air valves pair a large-orifice stage with a small-orifice stage in one body: the large stage discharge bulk air while pipelines fill and admit a
View specifications →Type
Combination Air Release Valves
Combination air release valves pair an air/vacuum function with a continuous air-release function in one assembly: they exhaust large air volumes at pipeline st
View specifications →Request a quote for air release valves
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