Effebi Hexa Spring Check Valve 1", Brass, Art. 2301G406

Effebi's dimension table gives the 1" Hexa a Kv of 10.3 m³/h, a body diameter of 47 mm, a length of 75 mm and a weight of 330 g. Kv describes the flow at a reference pressure drop; the actual flow in your circuit depends on the pump and the rest of the pipework.

For the 1" valve, Effebi gives PN 25, that is 25 bar at 20 °C, and a fluid temperature range of −5 to 110 °C. Steam is outside its scope. If your heating system runs close to these values, ask your installer to confirm the choice.

It suits the hot water of a heating circuit: Effebi names systems with radiators, boilers and pumps, and the fluid may reach 110 °C. Gas is not among the fields of use Effebi lists for Hexa, so on gas pipework fit a valve approved for gas instead.

Fit it so that forward flow lifts the POM pad from the NBR seat; reverse flow, helped by the spring, pushes the pad back and closes the valve. In a heating circuit this usually means the inlet faces the pump outlet. As both ends share the same G 1 female thread, the valve screws on either way, so check the flow direction before tightening.