6004.2.2.7 Treatment systems.
FC § 6004.2.2.7
The exhaust ventilation from gas cabinets, exhausted enclosures and gas rooms, and local exhaust systems required by FC 6004.2.2.4 and 6004.2.2.5 shall be directed to a treatment system. The treatment system shall be utilized to handle the accidental release of gas and to process exhaust ventilation. The treatment system shall be designed in accordance with FC 6004.2.2.7.1 through 6004.2.2.7.5 and Chapter 5 of the Mechanical Code. Exceptions: 1. Highly toxic and toxic gases – storage. A treatment system is not required for containers in storage when the following controls are provided: 1.1. Valve outlets are equipped with gas-tight outlet plugs or caps. 1.2. Handwheel-operated valves have handles secured to prevent movement. 1.3. Approved containment vessels or containment systems are provided in accordance with FC 6004.2.2.3.
2.Toxic gases – use. Treatment systems are not required for toxic gases supplied by portable containers not exceeding 1,700 pounds (771 kg) water capacity when the following controls are provided: 2.1. A listed or approved gas detection system with a sensing interval not exceeding 5 minutes. 2.2. A listed or approved automatic-closing fail-safe valve located immediately adjacent to container valves. The fail-safe valve shall close when gas is detected at the permissible exposure limit (PEL) by a gas detection system monitoring the exhaust system at the point of discharge from the gas cabinet, exhausted enclosure, ventilated enclosure or gas room. The gas detection shall comply with the requirements of FC 6004.2.2.10.
