- (a) At least one (1) attendant shall supervise the transfer of liquids from the time the connections are first made until they are finally disconnected.
(b)
- (1) Containers shall be filled or used only upon authorization of owner.
- (2) Containers shall be gauged and charged only in the open air or in buildings especially provided for that purpose.
- (c) Pumps used for transferring ammonia shall be recommended and labeled for ammonia service by the manufacturer.
- (d) Liquid pumps may be of piston, rotary, centrifugal, or regenerative type, designed for not less than two hundred fifty pounds per square inch gauge (250 psig) working pressure.
(e)
- (1) Positive displacement pumps shall have, installed off the discharge port, a constant differential relief valve discharging through a line of sufficient size to carry the full capacity of the pump at relief valve setting.
- (2) This setting and installation shall be according to pump manufacturer’s recommendation.
- (f) On the discharge side of the pump, before the relief valve line, there shall be installed a pressure gauge graduated from zero pounds per square inch gauge (0 psig) to four hundred pounds per square inch gauge (400 psig).
- (g) Centrifugal or regenerative pumps do not require a bypass relief valve, but the installation shall incorporate a line from the discharge side of the pump to the vapor space of the supplying tank and in this line, at accessible level, must be installed a shutoff valve.
- (h) Shutoff valves shall be installed within three feet (3’) of the inlet of the pump and within two feet (2’) of the discharge.
- (i) Compressors used for transferring and refrigerating ammonia shall be recommended and labeled for ammonia service by the manufacturer.
- (j) Compressors may be of reciprocating or rotary type designed for not less than two hundred fifty pounds per square inch gauge (250 psig) working pressure.
- (k) Plant piping shall contain shutoff valves located as close as practicable to compressor connections.
(l)
- (1) A relief valve large enough to discharge the full capacity of the compressor shall be connected to the discharge before any shutoff valve.
- (2) The discharging pressure of this valve shall not exceed three hundred pounds per square inch gauge (300 psig).
- (m) Compressors shall have pressure gauges graduated from zero pounds per square inch gauge (0 psig) to four hundred pounds per square inch gauge (400 psig) as suction discharge.
- (n) Adequate means, such as a drainable liquid trap, shall be provided on the compressor suction to minimize the entry of liquid into the compressor.
- (o) The pipe line to which the loading or unloading hoses are connected shall be equipped with a backflow check valve or excess flow check valve to prevent discharge of ammonia from the containers and the line in case of hose or fitting failure.