Questions You Should Know about Valve Housing

A.

Too much clearance between the rotor, endplates and or housing can result in air loss. Measure the rotor to endplate and rotor to housing clearances to confirm that they are an NFPA compliant 0.0079 inches. If the clearance is larger than this, it might be time to replace your rotor, rotary valve, or have it sent back to ACS for a repair or evaluation. Make sure to stick to a maintenance schedule and check your clearances at least every three months.

What mounting orientation should be used to install a safety valve?

Installing a safety valve in any position other than with the spindle vertical and upright may adversely affect performance and lifetime.

Section I – PG-71.2 – Every safety valve or safety relief valve shall be connected so as to stand in an upright position, with spindle vertical. EXCEPTION: PEB-15.3 (Electric Boilers) – Safety and safety relief valves shall be mounted in accordance with PG-71.2 with the spindle vertical. Electric boilers that do not exceed the diameter, volume, or pressure limits of PMB-2, may have a spring-loaded safety or safety relief valve(s) installed in other than the vertical position, provided that:

• The valve design is satisfactory for such position
• The valve is not larger than NPS ¾ (DN20)
• The maximum angle of deviation from vertical does not exceed 30 degrees
• The nozzle location is such that no material that could interfere with the operation of the valve can accumulate at the valve inlet
• The discharge opening of the valve body and discharge piping is oriented so that drainage is adequate

Section IV – Article 7 HG-701.1 – Safety valves and safety relief valves shall be installed with their spindles vertical. Article 8 HLW-810.2 – Safety relief valves shall be installed with their spindles upright and vertical with no horizontal connecting pipe, except that, when the safety relief valve is mounted directly on the water heater vessel with no more than 4 in. (102 mm) maximum interconnecting piping, the valve may be installed in the horizontal position with the outlet pointed down.

Section VIII – APPENDIX M-12 – Spring loaded safety and safety relief valves normally should be installed in the upright position with the spindle vertical. Where space or piping configuration preclude such an installation, the valve may be installed in other than the vertical position provided that:

• The valve design is satisfactory for such position
• The media is such that material will not accumulate at the inlet of the valve
• Drainage of the discharge piping is adequate

More information: 3 things to avoid when installing and operating safety relief valves