(a) This subpart prescribes standards for the use of liquefied petroleum gas for heating and cooking on inspected vessels, except ferries.

(b) It is the intent of the regulations in this subpart to permit liquefied petroleum gas systems of the vapor withdrawal type only. Cylinders designed to admit liquid gas into any other part of the system are prohibited.

(c) Except as provided by § 58.16-7(b), all component parts of the system, except cylinders, appliances, and low-pressure tubing, must be designed to withstand a pressure of 500 pounds per square inch without failure.

For the purpose of this subpart the term “liquefied petroleum gas” means any liquefied flammable gas which is composed predominantly of hydrocarbons or mixtures of hydrocarbons, such as propane, propylene, butane, butylene, or butadiene, and which has a Reid vapor pressure exceeding 40 pounds per square inch absolute at 100 °F as determined by ASTM D323 (incorporated by reference, see § 58.03-1).

(a) Cooking equipment using liquefied petroleum gas on vessels of 100 gross tons or more that carry passengers for hire must meet the requirements of this subpart.

(b) Cooking equipment using liquefied petroleum gas on vessels of less than 100 gross tons that carry passengers for hire must meet the requirements of § 25.45-2 or part 184, both of this chapter, as applicable.

(c) Systems using liquefied petroleum gas for cooking or heating on any other vessels subject to inspection by the Coast Guard must meet the requirements of this subpart.

(a) Gas appliances. (1) All gas-consuming appliances used for cooking and heating must be tested, listed, and labeled by an acceptable laboratory, such as:

(i) The American Gas Association Testing Laboratories.

(ii) UL Solutions.

(2) Continuous-burning pilot flames are prohibited for use on gas appliances when installed below the weather deck.

(3) Printed instructions for proper installation, operation, and maintenance of each gas-consuming appliance must be furnished by the manufacturer.

(b) Cylinders. (1) Cylinders in which liquefied petroleum gas is stored and handled must be constructed, tested, marked, maintained, and retested in accordance with 49 CFR part 178.

(2) All liquefied petroleum gas cylinders in service must bear a test date marking indicating that they have been retested in accordance with the regulations of the Department of Transportation.

(3) Regardless of the date of the previous test, a cylinder must be rejected for further service when it leaks; when it is weakened appreciably by corrosion, denting, bulging or other evidence of rough usage; when it has lost more than 5 percent of its tare weight; or when it has been involved in a fire.

(c) Safety-relief devices. All required safety-relief devices must be accepted as to type, size, pressure setting, and location by the Commandant (CG-ENG) as being in accordance with 49 CFR part 178.

(d) Valves, regulators, and vaporizers. All component parts of the system, other than cylinders and low-pressure distribution tubing between regulators and appliances, must be tested and approved by and bear the label of UL Solutions or other recognized testing laboratory.

(e) Plan approval. Drawings showing the location and installation of all piping, gas-consuming appliances, cylinders, and other component parts of the system must be submitted for approval.

(a) Each cylinder must have a manually operated screw-down shutoff valve fitted with a handwheel installed directly at the cylinder outlet.

(b) All cylinders must be protected by one or more safety relief devices complying with the requirements of § 58.16-10(a). The safety relief device must be a shutoff valve with an integral spring-loaded safety relief valve and supplementary fusible plug, the latter designed to yield when the cylinder has been emptied of liquid gas by the relief valve under conditions of exposure to excessive heat.

(c) Cylinder valves and safety relief devices must have direct communication with the vapor space of the cylinder.

(d) In addition to the cylinder valve, a multiple cylinder system must be provided with a two-way positive shutoff manifold valve of the manually operated type. The manifold valve must be so arranged that the replacement of empty cylinders can be made without shutting down the flow of gas in the system.

(e) A master packless shutoff valve controlling all burners simultaneously must be installed at the manifold of all gas-consuming appliances.

(a) All systems shall be provided with a regulating device so adjusted as to release gas to the distribution tubing at a pressure not in excess of 18 inches water column, or approximately 10.5 ounces per square inch.

(b) The low-pressure side of all regulators must be protected against excessive pressure by means of a suitable relief valve, which must be integral with the regulator. The relief valve must be set to start to discharge at a pressure not less than two times and not more than three times the delivery pressure.

(c) All reducing regulators must be fitted with a pressure gage located on the high-pressure side of the regulator.

(a) The piping between the cylinders and the appliances must be seamless annealed copper tubing or such other seamless tubing as may be approved by the Commandant.

(b) All high-pressure tubing between the cylinders and the regulators must have a minimum wall thickness of 0.049 inch. All low-pressure tubing between the regulator and appliances must have a minimum wall thickness of 0.032 inch.

(c) Tubing connecting fittings must be of the flare type; or connections may be soldered or brazed with material having a melting point in excess of 1,000 °F.

(a) Cylinders, regulating and safety equipment. (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) 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) Stowage of unconnected spare cylinders, filled or empty, must comply with the requirements for cylinders.

(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) 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) 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) 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.

(c) Gas-consuming appliances. All gas-consuming appliances must be permanently and securely fastened in place.

(d) Electrical. No electrical connections must be made within the cylinder housing.

(a) Installation. (1) After installation, the distribution tubing must be tested prior to its connection to the regulator and appliance by an air pressure of not less than 5 psig.

(2) After satisfactory completion of the tests prescribed in paragraph (a)(1) of this section, the distribution tubing must be connected to the regulator and appliance and the entire system subjected to a leak test as required by § 58.16-30(j).

(b) Periodic. Leak tests as required by § 58.16-30(j) must be conducted at least once each month and at each regular annual or biennial inspection. The tests required at monthly intervals must be conducted by a credentialed officer of the vessel or qualified personnel acceptable to the Officer in Charge, Marine Inspection. The owner, master, or person in charge of the vessel must keep records of such tests showing the dates when performed and the name(s) of the person(s) and/or company conducting the tests. Such records must be made available to the marine inspector upon request and must be kept for the period of validity of the vessel's current certificate of inspection. Where practicable, these records should be kept in or with the vessel's logbook.

(a) Compartments containing gas-consuming appliances which are located above the weather deck must be fitted with at least two natural ventilator ducts led from the atmosphere with one extending to the floor level and the other extending to the overhead of the compartment. Powered ventilation may be used provided the motor is outside the compartment.

(b) Compartments in which gas-consuming appliances are located entirely below the weather deck must be provided with powered ventilation of sufficient capacity to effect a change of air at least once every 6 minutes. The motor for the powered ventilation must be located outside the compartment.

(a) All liquefied petroleum gases must be effectively odorized by an agent of such character as to indicate positively by a distinctive odor, the presence of gas down to concentration in air of not over one-fifth the lower limit of combustibility.

(b) [Reserved]

(a) Before opening a cylinder valve, the outlet of the cylinder must be connected tightly to system; and in the case where only a single cylinder is used in the system, all appliance valves and pilots must be shut off before the cylinder valve is opened.

(b) Before opening cylinder valve after connecting it to system, the cylinder must be securely fastened in place.

(c) When cylinders are not in use their outlet valves must be kept closed.

(d) Cylinders when exhausted must have their outlet valves closed.

(e) Nothing must be stored in the metal enclosure except liquefied petroleum gas cylinders and permanently fastened parts of the system.

(f) Valve protecting caps, if provided, must be firmly fixed in place on all cylinders not attached to the system. Caps for cylinders in use may remain in the cylinder enclosure if rigidly fastened thereto.

(g) The opening to the cylinder enclosure must be closed at all times except when access is required to change cylinders or maintain equipment.

(h) Close master valve whenever gas-consuming appliance is not in use.

(i) No smoking is permitted in the vicinity of the cylinder enclosure when access to enclosure is open.

(j) Test system for leakage in accordance with the following procedure: With appliance valve closed, the master shutoff valve on the appliance open, and with one cylinder valve open, note pressure in the gage. Close cylinder valve. The pressure should remain constant for at least 10 minutes. If the pressure drops, locate leakage by application of liquid detergent or soapy water solution at all connections. Never use flame to check for leaks. Repeat test for each cylinder in a multicylinder system.

(k) Report any presence of gas odor.

(a) The outside of the cylinder enclosure housing liquefied petroleum gas cylinders, valves and regulators must be marked as follows:

(b) A durable and permanently legible instruction sign covering safe operation and maintenance of the gas-consuming appliance shall be installed adjacent to the appliance.

(c) “Operating Instructions” as listed in § 58.16-30 shall be framed under glass, or other equivalent, clear, transparent material, in plainly visible locations on the outside of the metal enclosure and near the most frequently used gas-consuming appliance, so they may be easily read.