Single Orifice Air Release Valve

Single orifice air release valve is an essential pipeline accessory installed on the high points of water supply, sewage, fire protection and industrial liquid pipelines. It is designed to automatically exhaust accumulated air trapped inside pipe systems and break vacuum during pipeline drainage, effectively solving a series of pipeline faults caused by air accumulation such as flow reduction, pipeline vibration, water hammer and pipeline burst risks. Different from double-orifice air valves with dual exhaust channels, this model adopts a single large-diameter exhaust orifice integrated with a floating ball sealing structure, featuring compact size, low cost and stable exhaust performance, which is widely adopted in small and medium-caliber water pipelines.

Air will continuously separate out from tap water and wastewater during long-distance transportation and accumulate at the highest positions of pipelines. If not discharged timely, air pockets will narrow the effective flow cross-section, increase pipeline resistance and pump energy consumption. When the pipeline stops transporting liquid and drains water, negative pressure will form inside the pipe, leading to pipeline deformation or collapse. The single orifice air release valve addresses these two core problems automatically without manual operation. When liquid flows normally, internal buoyancy pushes the floating ball to seal the small air outlet for micro-venting of tiny dissolved air; when large air blocks gather or the pipeline drains to create vacuum, the liquid level drops, the ball falls down to fully open the single main orifice for fast large-volume air exchange.

Structural Advantages

The valve body is integrally cast from ductile iron EN-GJS-500-7, with inner and outer fusion-bonded epoxy coating thicker than 250μm to resist rust and scale, meeting drinking water hygiene standards. The built-in floating ball is made of light-weight corrosion-resistant stainless steel or solid EPDM float, which has stable buoyancy and will not sink after long-term soaking. The sealing surface adopts elastic rubber cushion to achieve bubble-tight sealing when closed, avoiding medium leakage under nominal pressure PN10 and PN16. The whole structure contains few spare parts without complicated transmission components, so it is not easy to be stuck by sediment and impurities carried in water, greatly lowering maintenance frequency.

Compact overall dimension enables easy installation on pipeline tees, elbows and high-position vertical branches. Threaded and flanged connection options are available to match DN25-DN100 pipelines. The top detachable bonnet allows quick disassembly for regular cleaning of sediment without removing the whole valve from the pipeline. No extra control equipment or power supply is required, and it works purely relying on liquid buoyancy, bringing zero operating cost for long-term use.

Main Technical Specifications

Nominal pressure covers PN10 and PN16; applicable medium includes tap water, fire water, rainwater and low-corrosion neutral wastewater; working medium temperature ranges from 0℃ to 80℃. It passes strict shell pressure test of 1.5 times rated pressure and air tightness sealing test before delivery, guaranteeing no water seepage under full pipeline pressure.

Application Scope

This single orifice air release valve is ideal for municipal residential water supply networks, agricultural irrigation plastic pipelines, building fire protection piping, landscape water circulation systems and small sewage delivery lines. It optimizes pipeline transportation efficiency, protects pumps and pipe fittings from air-induced damage, and extends the overall service life of fluid conveying systems. Compared with compound double-orifice air valves, it is more cost-effective for conventional small-bore pipeline projects and becomes the standard matching air exhaust device for most civilian water pipeline engineering.