Minnesota Administrative Rules

4715.2210 PRESSURE RELIEF VALVES.

Subpart 1.

Installation.

Pressure relief valves shall have a relief rating adequate to meet the pressure conditions in the equipment served. They shall be installed in the cold water supply line to the heating equipment served except where scale formation from hard water may be encountered in which case they may be installed in the hot water supply line from the heating equipment served. There shall be no shutoff valve between the pressure relief valve and the tank. The setting shall not exceed the tank working pressure.

Subp. 2.

Temperature relief valves.

Temperature relief valves shall be of adequate relief rating, expressed in Btu/hr, for the equipment served. They shall be installed so that the temperature sensing element is immersed in the hottest water in the head or within the top six inches of the vertical portion of the tank. The valve shall be set to open when the stored water temperature is 210 degrees Fahrenheit (or less).

Subp. 3.

Combination pressure-temperature relief valves.

Combination pressure temperature relief valves may be used for storage equipment provided the other applicable requirements for individual pressure and individual temperature relief valves are met.

Subp. 4.

Installation of relief valves.

No check valve or shutoff valve shall be installed between any safety device and the hot water equipment used, nor shall there be any shutoff valve in the discharge pipe from the relief valve. The discharge pipe shall be full size and run to within 18 inches of the floor or a safe place of disposal.

Statutory Authority:

MS s 16B.59 to 16B.75; 326.37 to 326.45; 326B.101 to 326B.194; 326B.43 to 326B.49

History:

23 SR 686; L 2007 c 140 art 4 s 61; art 6 s 15; art 13 s 4; L 2008 c 337 s 64

Published Electronically:

May 14, 2012