The check valve is a structural part of the hydraulic circuit of the counter-current unit that prevents the backflow of water through the piping when the pump stops or when the pressure drops.
Without the check valve, undesirable drainage of water from the counter-current system could occur every time the pump stops, which would increase the strain on the hydraulics and prolong the start-up upon restart.
The part is made of durable plastic suitable for permanent contact with pool water. The installation of the check valve is carried out on the pressure-side piping and requires no special expertise beyond ordinary plumbing practice.
