Anti-shock/anti-slam air valves

Anti-surge air valves are used in water pipelines, pumping stations, desalination plants, industrial distribution networks, and seawater service to control air release and air admission during pipeline filling, normal operation, and draining. Their function is critical under transient conditions, where uncontrolled air discharge or rapid closure of the water column can lead to water hammer, sub-atmospheric pressure, noise, vibration, or mechanical loading of the pipe system.

This category includes CSA GOLIA 3F-AS, GOLIA 3F-RFP, GOLIA 2F IO, GOLIA 3F EO, GOLIA 3F RFP SUB, and the CSA VRCA valve. The GOLIA 3F-AS and 3F-RFP are combination air valves with anti-slam / anti-surge control. They discharge trapped air from pressurized pipelines and admit large air volumes during emptying or in the event of pipe rupture.

The GOLIA 3F-RFP incorporates an air flow restriction arrangement that acts as air velocity and differential pressure increase, controlling water column approach and reducing the risk of abrupt closure of the moving element. GOLIA designs are specified with body and cover in AISI 316, Duplex 2205, or Super Duplex 2507, with flanged connections DN50-DN400 to EN 1092-2 or ANSI Class 150, threaded connections 1"-2" BSP/NPT, design according to EN 1074, pressure ratings PN10-PN40, minimum operating pressure 0.2 bar, and maximum treated water temperature up to 60 °C.

The SUB version is intended for installations subject to flooding or where discharge spray or leakage from the valve outlet is not acceptable. In this configuration, the air flow is routed through a sealed system with threaded exhaust elbow. The associated increase in head loss should be included in air flow sizing calculations.

The CSA VRCA is a fast-acting, spring-loaded pressure relief valve for overpressure discharge at a preset and adjustable setpoint. Construction includes ductile iron body and cover in GJS 450-10 with stainless steel internal components, sizes DN50-DN200, EN 1092-2 flanges, pressure classes PN10-PN25, and setpoint ranges of 0-8, 8-16, and 16-25 bar.