Effebi Hexa Spring Check Valve 1 1/2", Brass, Art. 2301G408

Effebi's table gives the 1 1/2" Hexa a Kv of 24 m³/h. The body is 67 mm in diameter and 86 mm long, and the valve weighs 685 g. Kv is measured at a reference pressure drop, so the flow in your system also depends on the pump and the pipe layout.

The 1 1/2" Hexa carries a PN 18 rating, meaning 18 bar at 20 °C, and accepts fluids from −5 to 110 °C. It is not designed for steam. In a pressurised water or heating system, make sure the highest operating pressure stays within that limit.

On the hot water of heating systems, yes: Effebi lists heating with radiators, boilers and pumps, with fluid temperatures up to 110 °C. Gas is not one of the uses the maker gives for Hexa, so it must not be fitted on gas pipework; a valve approved for gas is needed there.

The pad opens only towards the outlet: forward flow pushes it off the NBR seat, and the AISI 302 spring presses it back when the flow stops. Install the valve with the inlet on the supply side and the outlet on the side that must not empty back. Both ends are G 1 1/2 female threads and the valve screws on either way, so check the direction first.