[Code of Federal Regulations]
[Title 46, Volume 2]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR56.20-9]

[Page 183-184]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 56_PIPING SYSTEMS AND APPURTENANCES--Table of Contents
 
                          Subpart 56.20_Valves
 
Sec. 56.20-9  Valve construction.

    (a) All valves must close with a right-hand (clockwise) motion of 
the handwheel or operating lever when facing the end of the valve stem. 
Gate, globe and angle valves must generally be of the rising-stem type, 
preferably with the stem threads external to the valve body. Where 
operating conditions will not permit such installations, the use of 
nonrising-stem valves will be permitted. Nonrising-stem valves, lever 
operated valves, and any other valve where, due to design, the position 
of the disc or closure mechanism is not obvious shall be fitted with 
indicators to show whether the valve is opened or closed. See Sec. 
56.50-1(g)(2)(iii). Such indicators are not required for valves located 
in tanks or similar inaccessible spaces where indication is provided at 
the remote valve operator. Operating levers of the quarter-turn (rotary) 
valves must be parallel to the fluid flow in the open position and 
perpendicular to the fluid flow in the closed position.
    (b) Valves of Class I piping systems (for restrictions in other 
classes refer

[[Page 184]]

to sections on low temperature service), having diameters exceeding 2 
inches must have bolted, pressure seal, or breech lock bonnets and 
flanged or welding ends, except that socket type welding ends shall not 
be used where prohibited by Sec. 56.30-5(c) of this part, Sec. 56.30-
10(b)(4) of this part for the same pressure class, or elsewhere in this 
part. For diameters not exceeding 2 inches, screwed union bonnet or 
bolted bonnet, or bonnetless valves of a type which will positively 
prevent the stem from screwing out of the body may be employed. Outside 
screw and yoke design must be used for valves 3 inches and larger for 
pressures above 600 pounds per square inch gage. Cast iron valves with 
screwed-in or screwed-over bonnets are prohibited. Union bonnet type 
cast iron valves must have the bonnet ring made of steel, bronze, or 
malleable iron.
    (c) Valves must be designed for the maximum pressure to which they 
may be subjected, but in no case shall the design pressure be less than 
50 pounds per square inch gage. The use of wafer type resilient seated 
valves is not permitted for shell connections unless they are so 
arranged that the piping immediately inboard of the valve can be removed 
without affecting the watertight integrity of the shell connection. 
Refer also to Sec. 56.20-15(b)(2)(iii) of this part. Large fabricated 
ballast manifold connecting lines exceeding 8 inches nominal pipe size 
must be designed for a pressure of not less than 25 pounds per square 
inch gage.
    (d) Disks or disk faces, seats, stems and other wearing parts of 
valves shall be made of material possessing corrosion and heat-resisting 
qualities suitable for the service conditions to which they may be 
subjected.
    (e) Plug cocks shall be constructed with satisfactory and positive 
means of preventing the plug from becoming loosened or removed from the 
body when the plug is operated. Cocks having plug locking arrangements 
depending on cotter pins are prohibited.
    (f) Cocks shall be marked in a straight line with the body to 
indicate whether they are open or closed.
    (g) Materials forming a portion of the pressure barrier shall comply 
with the applicable provisions of this part.

[CGFR 68-82, 33 FR 18843, Dec. 18, 1968, as amended by CGD 77-140, 54 FR 
40604, Oct. 2, 1989; CGD 95-012, 60 FR 48050, Sept. 18, 1995; USCG-2004-
18884, 69 FR 58346, Sept. 30, 2004]