REXUS is the manufacturer and distributor of the AirFlo Variable Orifice Air Valve technology.
AIRFLO Variable Orifice Air Valves is borne from decades of experience in the water and wastewater industry, coupled with an in depth and thorough understanding of how pipelines operate under varying conditions. This technology was specifically developed to provide optimum performance and efficient solutions for challenging pipeline applications. Areas of specific focus are efficient vacuum protection and automatic and adequate surge protection under rapid pipeline filling and pump trip conditions.
AIRFLO Variable Orifice Technology represents the next evolution in air valve technology and is the first substantial advancement in air valve design since the mid 1990’s. This patented technology is the first to adequately address the challenge of varying the size of the air valve orifice appropriately and automatically to flow conditions within the pipeline and thereby provide effective air discharge whilst also damping any potential surge.
An AIRFLO Variable Orifice Air Valve is a compact single chamber air valve design that provides four functions as standard. This includes; pressurised air release, large volume air discharge, vacuum protection and automatic surge protection.
This is currently the most advanced air valve design available on the market and is rapidly becoming the preferred specified air valve technology in the market. The reason for this is as follows:
Effective operation of an air release and vacuum break valve across the entire working cycle of a pipeline is essential to minimise the operating and maintenance costs of a pipeline system.
AIRFLO Variable Orifice Air Valves is focused on addressing the critical area of effective surge protection and air release as follows:
The design, under filling or pump trip conditions, features a patented automatic Variable Orifice device that is designed to uniformly decelerate water approaching at excessive speed, thereby limiting pressure rise upon valve closure.
The unique operating principle of AIRFLO's Variable Orifice, in addition to limiting pressure transients, attenuates the magnitude and amplitude of mass oscillation without damage to the valve or pipeline.
Surge damping of the AIRFLO under operating conditions is enhanced through the design of the control float which maintains a specifically calculated buoyancy allowing for a specified amount of air to be trapped in the valve chamber. This provides a cushioning benefit for pressure transients of short duration.
AIRFLO is one of few manufacturers that can provide air valves sizes up to DN300. Our standard range of valves is: DN25, DN50, DN80, DN100, DN150, DN200, DN250 and DN300.
The AIRFLO design lends itself to be manufactured for any possible working pressure. We offer valves in PN10, PN16, PN25, PN40 and PN64 pressure ratings with higher pressure ratings available on request.