Description 4mm Non-Return Valve for Pond Airline & Aerators This valve is designed to fit airline/fittings with an internal diameter of 4mm This valve is designed to prevent the flow of water/air back to your system. We recommend using a non-return valve with all aerators, in the event of the air pump being turned off/shutting down water can siphon through the airline and out your pond/tank having detrimental effects to your fish and electrical appliances When it comes to air fittings it is imperative that the fitting is not restrictive on the flow of air. If the airflow is restricted it will affect the performance of your aerator and even prevent it from working at all. Many non-return valves on the market are extremely hard to open and shut (require a huge amount of air pressure). However, this model of non-return valve can be used with even the smallest of air pumps with no adverse effects. Suitable for: water, air, petrol, diesel, gas, oils, etc Can be used for horizontal pipe or vertical pipe. Flow smoothly, low resistance, good sealing performance, short spool stroke, small off valve impact force, and high reliability.
