Description Where replenishment of water in floor drain traps is required, trap primer valves shall be 1/2" FIP inlet x 1/2" MIP outlet, automatic trap primer valves which activate with a 10 PSIG pressure drop between 30-150 PSIG. Water release shall be factory set. Trap primer valve shall have large port openings and a non-corrosive brass finish.
The trap primer periodically refills the water trap in the fixture. For example, in normally dry floor areas where there is a floor drain, the water in the trap will evaporate and allow sewer gas to flow through the now dry trap. The trap seal essentially covers and seals the floor drain to lessen the amount of evaporation and gas flow.