Airmax HPQR High Pressure Air Regulator, 42 kg/cm²

A pressure regulator holds a chosen downstream pressure while the supply above it varies. The HPQR is the high pressure member of the Airmax air preparation range: it accepts an inlet from 0.5 up to 42 kg/cm² and delivers a regulated outlet anywhere from 0 to 30 kg/cm², which is well above the 10 bar band an ordinary FRL regulator works in. It is the unit specified where air is taken from a high pressure receiver, a booster or a nitrogen or air cylinder and has to be dropped to a usable working pressure.

Construction is piston-sensed rather than diaphragm-sensed, which suits the higher inlet. Turning the T-handle clockwise compresses the setting spring, which loads the piston and opens the plunger against its seat until the outlet reaches the set value; the valve then throttles to hold it. The handle locks once set. Sealing is by NBR V-seals and an NBR O-ring, and the maker rates the closed valve bubble tight. Body, bonnet cover, piston, plunger and bottom plug are aluminium, the setting spring is spring steel and the plunger spring is stainless steel.

A 1/4" BSP gauge port is provided so the regulated pressure can be read, and mounting is available for panel or bracket fixing. Sizes run 1/4", 1/2", 3/4" and 1", the first two in a 145 mm high body and the larger two in a 230 mm body.

Two points to settle before ordering. First, confirm the required regulated range: the outlet tops out at 30 kg/cm² even though the inlet is rated to 42 kg/cm². Second, a regulator is not a relief valve - it controls pressure in normal operation but does not protect the downstream circuit against a failed regulator, so where overpressure would be dangerous a separate relief device is still needed. Specify size, thread form, and the inlet and outlet pressures the duty requires.