(a) Cylinders, regulating and safety equipment.

1. (1) Cylinders, regulating and safety equipment must be installed in a substantially constructed and firmly fixed metal enclosure located on or above the weather deck. The cylinder enclosure must have access from the weather deck only. The enclosure must be provided with top and bottom ventilation consisting of a fresh air inlet pipe and an exhaust pipe both entering through the top of the cylinder housing. The enclosure must be constructed so that when the access opening is closed, no gas can escape except through the ventilation system.
2. (2) Cylinders, regulating and safety devices must be securely fastened and supported within the metal enclosure. The cylinders and high-pressure equipment must be so mounted as to be readily accessible and capable of easy removal for refilling and inspection. The stowage of high-pressure equipment in the housing must be such that the cylinder valves can be readily operated, and the pressure gage dial is easily visible. Where possible cylinders must be mounted in an upright position.
3. (3) Stowage of unconnected spare cylinders, filled or empty, must comply with the requirements for cylinders.
4. (4) All valves, manifolds and regulators must be securely mounted in locations readily accessible for inspection, maintenance, and testing, and must be adequately protected.
5. (5) Discharge of the safety relief valves must be vented away from the cylinder, and insofar as practicable, upward into the open atmosphere, but in all cases so as to prevent impingement of the escaping gas onto a cylinder.

(b) Piping.

1. (1) All piping must be installed so as to provide minimum interior runs and adequate flexibility. The piping at the cylinder outlets must be fitted with flexible metallic connections to minimize the effect of cylinder movement on the outlet piping.
2. (2) Distribution lines must be protected from physical damage and be readily accessible for inspection. Lines must be substantially secured against vibration by means of soft nonferrous metal clips without sharp edges in contact with the tubing. When passing through decks or bulkheads, the lines must be protected by ferrules of nonabrasive material. The distribution lines must be continuous length of tubes from the regulator to the shutoff valve at the appliance manifold.