(a) All discharge piping from the fuel oil service pumps to burners must be seamless steel with a thickness of at least Schedule 80. Short lengths of steel, or annealed copper nickel, nickel copper, or copper pipe and tubing may be used between the fuel oil burner front header manifold and the atomizer head to provide flexibility. All material used must meet the requirements of subpart 56.60. The use of non-metallic materials is prohibited. Flexible metallic tubing may be used when approved by the Marine Safety Center. Tubing fittings must be of the flared type except that flareless fittings of the nonbite type may be used when the tubing is steel, nickel copper or copper nickel.

(b)(1) All vessels having oil fired boilers must have at least two fuel service pumps, each of sufficient capacity to supply all the boilers at full power, and arranged so that one may be overhauled while the other is in service. If installed, fuel oil heaters must be so arranged that any heater may be overhauled while the other is in service. Suction and discharge strainers must be capable of being cleaned without interrupting the oil supply.

(2) All auxiliary boilers, except those furnishing steam for vital equipment and fire extinguishing purposes, may be equipped with a single fuel oil service pump. Such pumps need not be fitted with discharge strainers.

(3) Strainers must be located so as to preclude the possibility of spraying oil on the burner or boiler casing, or be provided with spray shields. Coamings, drip pans, etc., must be fitted under fuel oil service pumps, heaters, etc., where necessary to prevent oil drainage to the bilge.

(4) Boilers burning fuel oils of low viscosity need not be equipped with fuel oil heaters.

(c) Piping between service pumps and burners must be located so as to be readily observable, and all bolted flange joints must be provided with a spray shield to deflect spray in case of a leak. Fuel pump or heater relief valves must discharge back to the settling tank or the suction side of the pump. The return line from the burners must be so arranged that the suction piping cannot be subjected to discharge pressure.

(d) If threaded-bonnet valves are employed, they must be of the union-bonnet type capable of being packed under pressure.

(e) Unions must not be used for pipe diameters of 1 inch and above.

(f) Boiler header valves of the quick closing type must be installed in the fuel supply lines as close to the boiler front header as practicable. The location is to be accessible to the operator or remotely controlled.

(g) Bushings and street ells are not permitted in fuel oil discharge piping.

(h) Each fuel-oil service pump must be equipped with controls as required by § 58.01-25 of this subchapter.