46 CFR 56.50-25 - Safety and relief valve escape piping.

§ 56.50-25 Safety and relief valve escape piping.

(a) Escape piping from unfired steam generator, boiler, and superheater safety valves shall have an area of not less than that of the combined areas of the outlets of all valves discharging thereto and shall be led as near vertically as practicable to the atmosphere.

(b) Expansion joints or flexible pipe connections shall be fitted in escape piping. The piping shall be adequately supported and installed so that no stress is transmitted to the safety valve body.

(c) Safety or relief valve discharges, when permitted to terminate in the machinery space, shall be led below the floorplates or to a remote position to minimize the hazardous effect of the escaping steam.

(d) The effect of the escape piping on the operation of the relief device shall be considered. The back pressure in the escape piping from the main propulsion steam generator should not exceed 10 percent of the relief device setting unless a compensated relief device is used. Back pressure must be calculated with all relief valves which discharge to a common escape pipe relieving simultaneously at full capacity.

[CGFR 68-82, 33 FR 18843, Dec. 18, 1968, as amended by CGD 77-140, 54 FR 40608, Oct. 2, 1989; CGD 95-012, 60 FR 48050, Sept. 18, 1995]

This is a list of United States Code sections, Statutes at Large, Public Laws, and Presidential Documents, which provide rulemaking authority for this CFR Part.

This list is taken from the Parallel Table of Authorities and Rules provided by GPO [Government Printing Office].

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United States Code
Presidential Documents

Executive Order ... 12234

Executive Order ... 12777

Title 46 published on 16-Dec-2017 03:49

The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 46 CFR Part 56 after this date.

  • 2016-07-22; vol. 81 # 141 - Friday, July 22, 2016
    1. 81 FR 48220 - Harmonization of Standards for Fire Protection, Detection, and Extinguishing Equipment
      GPO FDSys XML | Text
      Final rule.
      This final rule is effective August 22, 2016. The incorporation by reference of certain publications listed in the rule is approved by the Director of the Federal Register on August 22, 2016.
      33 CFR Parts 140, 145, 148, and 149