View all text of Subpart 56.50 [§ 56.50-1 - § 56.50-110]
§ 56.50-1 - General (replaces 122).
The requirements in this subpart for piping systems apply instead of those in Section 122 of ASME B31.1 (incorporated by reference; see § 56.01-2). The following installation requirements are applicable to all systems:
(a) Where pipes and scuppers are carried through watertight or oiltight bulkheads, decks, or tank tops, or are carried through fire control bulkheads and decks, the integrity of the structure must be maintained. Lead or other heat sensitive materials must not be used in piping systems in bulkhead or deck penetrations where fire would impair the integrity of the penetration. (For nonmetallic or plastic pipe installations, see § 56.60-25(a).) Openings in structure through which pipes pass must be reinforced where necessary. Metallic materials having a melting point of 1,700 °F or less are considered heat sensitive and if used must be suitably insulated.
(b)(1) Pipes piercing the collision bulkhead must be fitted with valves operable from above the bulkhead deck and the valve must be fitted inside the forepeak tank adjacent to the collision bulkhead. The pipe penetrating the collision bulkhead must be welded to the bulkhead on both sides. The valve body must be of steel or ductile cast iron.
(2) Passenger vessels must not have the collision bulkhead pierced below the margin line by more than one pipe conveying liquids in the forepeak tank.
(c) Valves and cocks not forming part of a piping system are not permitted in watertight subdivision bulkheads. However, sluice valves or gates in oiltight bulkheads of tank vessels may be used if approved by the Marine Safety Center.
(d) Piping must generally not be run over switchboards, and must be installed as far away from other electrical equipment as practicable. When such leads are necessary, provision must be made to prevent leakage from damaging the equipment.
(e) Stuffing boxes must not be used on deep tank bulkheads, double bottoms or in any position where they cannot be easily examined. This requirement does not apply to ore carriers operating on the Great Lakes or cargo lines of oil tankers.
(f) Piping systems must be installed so that under no condition will the operation of safety or relief valves be impaired.
(g)(1) Power actuated valves may be used if approved for the system by the Marine Safety Center. All power-actuated valves must have a backup manual means of operation.
(2)(i) Remote valve controls must be fitted with nameplates describing the applicable system.
(ii) Remote valve controls must be accessible under normal service conditions.
(iii) Remote valve controls, except reach rods, must be fitted with indicators that show whether the valves they control are open or closed. Valve position indicating systems must be independent of valve control systems.
(iv) Valve reach rods must be adequately protected.
(v) Solid reach rods must be used in tanks containing liquids, except that reach rods of constructed of extra-heavy pipe may be considered acceptable by the OCMI.
(3) Air-operated remote-control valves must be provided with self-indicating lines at the control boards that indicate the desired valve positions, such as open or closed.
(h) Suitable drains must be provided at low points of piping systems.
(i) Valves and cocks must be easily accessible. Valves attached to the shell of the vessel or to sea chests located below deck plating must be operable from above the deckplates.
(j) When welded fabrication is employed, a sufficient number of detachable joints must be provided to facilitate maintenance of machinery.
(k) Piping systems used where the fluid temperature exceeds 150 °F must be suitably insulated as necessary to preclude injury to personnel.
(l) Where pipes are run through dry cargo spaces they must be protected from mechanical injury by a suitable enclosure or other means.