Type A Combination Air Valve (Double Ball) EN 1074-4
Our Type A double ball combination air valve is designed and manufactured in accordance with EN 1074-4, providing all three essential air management functions in a single compact unit. It combines a large-orifice chamber for bulk air evacuation and intake with a small-orifice chamber for continuous air release under operating pressure, ensuring complete protection for water pipelines throughout their entire lifecycle.
During pipeline filling, the large orifice rapidly discharges accumulated air to allow fast, safe filling and prevent air locks. During normal operation, the small orifice automatically releases micro-bubbles and trapped air pockets that collect at high points, maintaining pipeline efficiency and preventing increased friction loss, corrosion, and water hammer. During draining or pump shutdown, the large orifice admits large volumes of air to prevent vacuum formation and pipe collapse.
The valve body is cast in high-grade ductile iron with a fusion-bonded epoxy coating, while the float mechanism uses stainless steel floats with EPDM sealing elements for reliable, corrosion-free performance. Flanged ends per EN 1092-2 and pressure ratings of PN10 / PN16 make it suitable for potable water and wastewater systems, with every unit pressure-tested to EN 12266-1 before shipment.
- Size Range: DN50-DN200
- Type A Combination Design — Per EN 1074-4, integrates large-orifice and small-orifice functions in one body.
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Three Essential Functions in One Unit:
- Air discharge — Rapidly expels large air volumes during pipeline filling
- Air admission / vacuum relief — Draws in air during draining or pump shutdown to prevent vacuum collapse
- Automatic air release — Continuously vents trapped air under pressure during operation
- Double Float Mechanism — Separate stainless steel floats for large and small orifices ensure precise, reliable sealing.
- Superior Materials — Ductile iron body (GGG50), SS304/SS316 floats, and EPDM seals for long service life.
- Corrosion Protection — Fusion-bonded epoxy coating approved for potable water service.
- Pressure Ratings PN10 / PN16 — Suitable for water supply, wastewater, and irrigation networks.
- Standard Flanged Ends — Flanges drilled to EN 1092-2 for direct pipeline installation.
- Bubble-Tight Sealing — Float-actuated closure provides a drip-tight seal under full operating pressure.
- Tested to International Standard — Every valve pressure-tested to EN 12266-1 before shipment.
- Wide Size Range — Available from DN50 to DN300 to cover typical water network requirements.
