The Air Valve (Vent-O-Mat Series RBX) is an “anti-shock” double-orifice air release and vacuum break valve for water pipelines. It combines high-volume air discharge during filling, high-volume air intake during draining and pressurised air release during operation, while its integral anti-shock orifice mechanism automatically dampens surge and water hammer without any external mechanical device.

Features & Specifications

• Double orifice (small and large) with anti-shock orifice mechanism for automatic surge alleviation

• Large-orifice diameter equal to nominal valve size for maximum vacuum protection

• Functions: air discharge on filling, air intake on draining, pressurised de-aeration and surge dampening

• Screwed DN25–DN50 and flanged DN80–DN200 configurations

• Pressure ratings PN16, PN25 and PN40; operating range 0.5 bar to rated maximum

• Operating temperature 4–80 °C; suitable for potable or strained raw water

• Barrel in AISI 316L stainless steel; fusion-bonded epoxy powder-coated ductile-iron flanges (mild steel on PN40)

• High-density polyethylene floats, EPDM seals, AISI 316 nozzle and stainless-steel fasteners

• Flanges to BS EN 1092 PN10/16/25/40 and ANSI B16.5 Class 150 & 300; tested to 1.5× rated working pressure

Dimensions & Technical Data

Component / material specification (sectional drawing) and overall dimensions and weights. Flanged DN80–DN100 example (dimension A): DN80 = 235 mm, weight 22.5–24 kg; DN100 = 235 mm, weight 22.5–24 kg. Operating temperature 4 °C to 80 °C.