Minnesota Administrative Rules

5230.5007 SECTION 11, OVERPRESSURE PROTECTION DEVICES.

Subpart 1.

Section 11.1.5.

ANSI/IIAR 2, section 11.1.5, is amended to read as follows:

11.1.5. Relief valves shall not be located in refrigerated spaces unless precautions are taken to prevent moisture migration into the valve body or relief valve vent line. A drip pocket the size of the discharge pipe and at least 24 inches in length must be installed below a vertical riser in the discharge pipe and must be fitted with a drain plug or valve.

Subp. 2.

Section 11.1.6.2.

ANSI/IIAR 2, section 11.1.6.2, is amended by adding the following paragraph at the end:

Rupture discs may only be used when installed in series with a pressure relief valve.

Subp. 3.

Section 11.2.5.

ANSI/IIAR 2, section 11.2.5, is amended to read as follows:

11.2.5. Pressure vessels of 10 ft³ [0.3 m³] or more internal gross volume shall be protected by one or more dual pressure relief device(s). Dual pressure relief valves shall be installed with a three-way valve to allow testing or repair. When dual relief valves are used, each valve must meet the requirements of section 11.2.7. When multiple dual relief valve assemblies are used,

a. the sum of the capacities of the pressure relief devices actively protecting the vessel must equal or exceed the requirements of section 11.2.7, and

b. the capacity of any dual relief assembly whose manifold valve is set to a position other than fully seated (one side open and one side closed) shall be counted to be zero.

Statutory Authority:

MS s 326B.925

History:

34 SR 145

Published Electronically:

September 30, 2009