[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: 46CFR56.30-20]

[Page 190]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 56_PIPING SYSTEMS AND APPURTENANCES--Table of Contents
 
        Subpart 56.30_Selection and Limitations of Piping Joints
 
Sec. 56.30-20  Threaded joints.

    (a) Threaded joints may be used within the limitations specified in 
subpart 56.15 of this chapter and within other limitations specified in 
this section.
    (b) (Reproduces 114.1.) All threads on piping components must be 
taper pipe threads in accordance with the applicable standard listed in 
Table 56.60-1(b). Threads other than taper pipe threads may be used for 
piping components where tightness of the joint depends on a seal weld or 
a seating surface other than the threads, and where experience or test 
has demonstrated that such threads are suitable.
    (c) Threaded joints may not be used where severe erosion, crevice 
corrosion, shock, or vibration is expected to occur; or at temperatures 
over 925 [deg]F. Size limitations are given in Table 56.30-20(c) of this 
section.

               Table 56.30-20(c)--Threaded Joints \1\ \2\
------------------------------------------------------------------------
       Maximum nominal size, inches          Maximum pressure, p.s.i.g.
------------------------------------------------------------------------
Above 2........................  (Not permitted in Class I
                                             piping service.)
Above 1 up to 2.....  600.
Above \3/4\ up to 1.  1,200.
\3/4\ and below................  1,500.
------------------------------------------------------------------------
\1\ Further restrictions on the use of threaded joints appear in the low
  temperature piping section.
\2\ Threaded joints in hydraulic systems are permitted above the
  pressures indicated for the nominal sizes shown when commercially
  available components such as pumps, valves and strainers may only be
  obtained with threaded connections.

    (d) Pipe with a wall thickness less than that of standard weight of 
ANSI B36.10 steel pipe must not be threaded regardless of service. For 
additional threading limitations for pipe used in steam service over 250 
pounds per square inch or water service over 100 pounds per square inch 
and 200 [deg]F, see part 104.1.2(c)(1) of ANSI B31.1. Restrictions as to 
the use of threaded joints appear for low temperature piping and should 
be checked when designing for these systems.

[CGFR 68-82, 33 FR 18843, Dec. 18, 1968, as amended by CGFR 69-127, 35 
FR 9978, June 17, 1970; CGD 73-254, 40 FR 40164, Sept. 2, 1975; CGD 77-
140, 54 FR 40606, Oct. 2, 1989]