For safety and to prevent air pump damage all air pumps should have a one-way check valve mounted in the airline. This check valve works for all applications including consumer and light industrial/commercial. Check valves prevent water from moving into the air pump tubing once power is turned off to the air pump. Without this check valve and depending on how the air pump is installed water or other fluids can move up the airline and into the air pump causing damage to the air pump and increasing chances of electrical shock or internal damage to the air pump.
