All Direct Expansion Refrigeration Systems containing more than 100 pounds (45.36 kg) of refrigerant shall be provided with a hand operated emergency valve. Such device shall be connected to the low side of the refrigeration system and be located where the emergency valve is readily available for Fire Department use. Valves shall be identified and operating instructions for the use of the emergency valve shall be provided at the location of the valve. Hand operated emergency valves shall be of the following sizes and a maximum inlet pipe length of one hundred (100) feet (30.48 m):
Pounds of Refrigerant in System | Valve Size |
100 – 200 | 1 inch nominal pipe size |
201 – 300 | 1 1/4 inches nominal pipe size |
301 – 500 | 1 1/2 inches nominal pipe size |
501 – 1,000 | 2 inches nominal pipe size |
above 1,000 | 3 inches nominal pipe size |