Refrigerants shall be discharged as follows:
a) Where the discharge of a refrigerant from a pressure relief valve or hand operated emergency valve to the outside atmosphere is required for systems containing more than 20 pounds (9.072 kg) of Group 1 refrigerants, the discharge pipe outlet shall be at least 12 feet (3.6576 m) above the ground, at least 20 feet (6.096 m) from any fire escape and at least 10 feet (3.048 m) from any door, fixed or operable window, air intake or exhaust duct. Piping shall terminate downward at an angle of 45 degrees from the horizontal.
b) Where the discharge of a refrigerant from a pressure relief valve to the outside atmosphere is required for systems containing not more than 20 pounds (9.072 kg) of Group 1 refrigerants, the discharge pipe outlet shall be at least 12 feet (3.6576 m) above ground, at least 20 feet (6.096 m) from any fire escape and at least 2 feet (0.6096 m) from any door, fixed or operable window, air intake or exhaust duct. Piping shall terminate downward at an angle of 45 degrees from the horizontal.
c) Where the discharge of a refrigerant from a pressure relief valve to the outside atmosphere is required for a system containing Group 2 refrigerants, piping shall terminate above the roof of the highest story of the building, and shall be at least 40 feet (12.192 m) from any adjoining building which extends above the roof and at least 40 feet (12.192 m) from any penthouse, skylight, fixed ladder or other means of access to the roof, or air intake or exhaust duct system. Piping shall terminate downward at an angle of 45 degrees from the horizontal, and shall be provided with a permanent warning sign attached to the piping at the point of termination. The sign shall have a yellow background and shall state in black letters not less than 3 inches (76.2 mm) in height and with the following wording:
AMMONIA VENT - DANGER AMONIACO DESCARGA - PELIGRO |
d) Relief valves may be vented to the low pressure side of a system, provided that the low pressure side is equipped with a relief device vented to the outside atmosphere.
e) Discharge piping from a relief device which does not exceed 100 feet (30.48 m) in length shall have a nominal pipe size which is not smaller than the outlet size of the relief device. When discharge piping exceeds 100 feet (30.48 m) in length pipe size shall be increased to the next larger nominal pipe size.
f) Discharge from more than one relief valve may run into a common header provided that the cross- sectional area of the common header is equal to or greater than the aggregate cross-sectional area of the discharge ports of all the valves connected to the common header.