Product Features: Releases air during charging and admits air during emptying of water main lines Available in double orifice and single orifice Single orifice are available from 15mm to 50mm in screwed and flanged type Double orifice are available from 40mm to 150mm in flanged type only Rubber coated timber balls are dynamically balanced to give trouble free working Isolating valves if required are available optionally Test Pressure (Hydraulic) : Body : 1.5 MPa Seat : 1.0 MPa 1 Bar = 0.1 MPa = 1.019 Kgcm² = 14.50 PSI