1. the check valve to prevent water damage to the front end air pump or other equipment. After joining the check valve pump can also be placed below the surface above water, prevent water backflow when the pump power stopped working at risk.

2. check valve which prevents water damage front end air pump or other equipment. For sufficient oxygen pump due to internal and external pressure suddenly stopped work to poor water flow reversed, after joining the check valve pump can be placed higher than the water below the surface, there is no question of risk of water backflow when the pump power stopped working. Damaged aeration pumps and water spills in the cylinder form property damage, is a small guard gas facilities!