[Code of Federal Regulations]

[Title 46, Volume 4]

[Revised as of October 1, 2006]

From the U.S. Government Printing Office via GPO Access

[CITE: 46CFR98.25-40]



[Page 83]

 

                            TITLE 46_SHIPPING



                  (This book contains parts 90 to 139)

 

   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)

 

PART 98_SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR 

CERTAIN DANGEROUS CARGOES IN BULK--Table of Contents

 

                 Subpart 98.25_Anhydrous Ammonia in Bulk

 

Sec.  98.25-40  Valves, fittings, and accessories.



    (a) All valves, flanges, fittings and accessory equipment shall be 

of a type suitable for use with anhydrous ammonia and shall be made of 

steel, or malleable or nodular iron meeting the requirements of Sec.  

56.60-1 of subchapter F (Marine Engineering) of this chapter. Valves 

shall be fitted with noncorrosive material suitable for ammonia service. 

Valves, flanges, and pipe fittings shall be of the square or round 

tongue and groove type or raised-face, United States of America Standard 

300-pound standard minimum, fitted with suitable soft gasket material. 

Welded fittings shall be used wherever possible and the number of pipe 

joints shall be held to a minimum. Screwed joints are not permitted for 

pipe diameters exceeding 2 inches. Nonferrous materials, such as copper, 

copper alloys and aluminum alloys, shall not be used in the construction 

of valves, fittings or accessory equipment. Brazed joints are 

prohibited.

    (b) Each tank shall be provided with the necessary fill and 

discharge liquid and vapor shut-off valves, safety relief valves, liquid 

level gaging devices, thermometer well and pressure gage, and shall be 

provided with suitable access for convenient operation. Connections to 

tanks installed below the weather deck shall be made to a trunk or dome 

extending above the weather deck. Connections to the tanks shall be 

protected against mechanical damage and tampering. Other openings in the 

tanks, except as specifically permitted by this part, are prohibited.

    (c) All connections to the tanks, except safety devices and liquid 

level gaging devices, shall have manually operated shut-off valves 

located as close to the tank as possible.

    (d) Excess flow valves where required by this section shall close 

automatically at the rated flow of vapor or liquid as specified by the 

manufacturer. The piping, including valves, fittings and appurtenances, 

protected by an excess flow valve, shall have a greater capacity than 

the rated flow of the excess flow valve.

    (e) Liquid level gaging devices which are so constructed that 

outward flow of tank contents shall not exceed that passed by a No. 54 

drill size opening, need not be equipped with excess flow valves.

    (f) Pressure gage connections need not be equipped with excess flow 

valves if the openings are not larger than No. 54 drill size.

    (g) Excess flow valves may be designed with a bypass, not to exceed 

a No. 60 drill size opening, to allow equalization of pressure.

    (h) Prior to disconnecting shore lines, the pressure in the liquid 

and vapor lines shall be relieved through suitable valves installed at 

the loading header.

    (i) Relief valves shall be fitted in liquid lines which may be 

subject to excessive pressure caused by liquid full condition, and the 

escape from the relief valves shall be piped to the venting system.

    (j) The pressure gage shall be located at the highest practical 

point. The thermometer well shall terminate in the liquid space and be 

attached to the shell by welding with the end of the fitting being 

provided with a gas-tight screwed plug or bolted cover.



[CGFR 65-50, 30 FR 17022, Dec. 30, 1965, as amended by CGFR 68-82, 33 FR 

18902, Dec. 18, 1968; CGFR 70-10, 35 FR 3712, Feb. 25, 1970]