Plumbing – Does the height of a water heater safety valve matter

plumbingsafetywater-heater

I just replaced the safety valve on my water heater. The only immediately available replacement was an inch taller than the original. It is still in contact with the water. Is it safe?

This is the exact fit replacement part (it was not in stock locally): http://www.homedepot.com/p/Rheem-PROTECH-3-1-4-in-Standard-Shank-Water-Heater-Temperature-and-Pressure-Relief-Valve-SP12574/205651345

This is the part I bought (it is taller and the temperature rod is shorter): http://www.homedepot.com/p/Cash-Acme-3-4-in-Bronze-NCLX-5LX-Temperature-and-Pressure-Relief-Valve-with-2-1-2-in-Shank-MNPT-Inlet-x-FNPT-Outlet-23577-0150/203164748

Is this replacement part adequately safe or should I go ahead and order the exact fit?

Best Answer

TPR valve shall extend into the heater tank and monitor the temperature in the top 6 inches of the heater. The discharge pipe shall terminate within 6 inches over the floor and not have any threads on the end, nor are there to be any valves in it.

  1. All pressurized storage-type water heaters and unfired hot water storage tanks shall be equipped with one or more combination temperature and pressure relief valves. The temperature steam rating of a combination temperature and pressure relief valve or valves shall equal or exceed the energy input rating in BTU per hour of the water heater. No shut off valve or other restricting device may be installed between the water heater or storage tank and the combination temperature and pressure relief valve.

  2. All pressurized non-storage type water heaters shall be provided with a pressure relief valve installed at the hot water outlet with no shut off valve between the heater and the relief valve.

3. Temperature and pressure relief valves shall be installed so that the sensing element of the valve extends into the heater tank and monitors the temperature in the top 6 inches of the heater or tank.

  1. Every relief valve which is designed to discharge water or steam shall be connected to a discharge pipe.

    5 (a) The discharge pipe and fittings shall be made of a material acceptable for water distribution piping in accordance with s.Comm 84.30 (4) (e) 1.

    5 (b) The discharge pipe and fittings shall have a diameter not less than the diameter of the relief valve outlet.

    5 (c) The discharge pipe may not be trapped.

    5 (d) No valve may be installed in the discharge pipe.

5 (e) The discharge pipe shall be installed to drain by gravity flow to a floor served by a floor drain or to a receptor in accordance with s. Comm 82.33 (8). The outlet of the discharge pipe shall terminate within 6 inches over the floor or receptor, but not less than a distance equal to twice the diameter of the outlet pipe. The discharge pipe may not be threaded.

(source)

Related Topic