Pressure Relief Valves

(1) All pressure relief valves on Air Tanks shall conform to the ASME and National Board Codes as adopted by 522 CMR 7.00. (2) All tanks, the contents of which are likely to cause interference with the operation of a pressure relief valve if attached directly to the Air Tank, shall have the pressure relief valve connected in such a manner as to avoid such interference. Intercoolers and aftercoolers shall not be classed as primary vessels, but shall be protected by adequate pressure relief valves. (3) When the pressure relief valve covered by 522 CMR 7.00 is exposed to the elements and freezing temperatures, they shall be located on the discharge pipe from the compressor as near to the Air Tank as practical.