[Code of Federal Regulations]
[Title 46, Volume 7]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR197.462]

[Page 436]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 197_GENERAL PROVISIONS--Table of Contents
 
                 Subpart B_Commercial Diving Operations
 
Sec. 197.462  Pressure vessels and pressure piping.

    (a) The diving supervisor shall ensure that each pressure vessel, 
including each volume tank, cylinder and PVHO, and each pressure piping 
system is examined and tested as required by this section and after any 
repair, modification or alteration to determine that they are in 
satisfactory condition and fit for the service intended.
    (b) Pressure vessels and pressure piping shall be examined annually 
for mechanical damage or deterioration. Any defect that may impair the 
safety of the pressure vessel or piping shall be repaired and pressure 
tested to the satisfaction of the Officer in Charge, Marine Inspection.
    (c) The following tests shall be conducted at least every three 
years:
    (1) All piping permanently installed on a PVHO shall be pressure 
tested.
    (2) PVHOs subject to internal pressure shall be leak tested at the 
maximum allowable working pressure using the breathing mixture normally 
used in service.
    (3) Equivalent nondestructive testing may be conducted in lieu of 
pressure testing. Proposals to use nondestructive testing in lieu of 
pressure testing shall be submitted to the Officer in Charge, Marine 
Inspection.
    (d) Unless otherwise noted, pressure tests conducted in accordance 
with this section shall be either hydrostatic tests or pneumatic tests.
    (1) When a hydrostatic test is conducted on a pressure vessel, the 
test pressure shall be no less than 1.25 times the maximum allowable 
working pressure.
    (2) When a pneumatic test is conducted on a pressure vessel, the 
test pressure shall be the maximum allowable working pressure stamped on 
the nameplate.
    (3) When a pneumatic test is conducted on piping, the test pressure 
shall be no less than 90 percent of the setting of the relief device.
    (4) Pressure tests shall be conducted only after suitable 
precautions are taken to protect personnel and equipment.
    (5) When pressure tests are conducted on pressure vessels or 
pressure piping, the test pressure shall be maintained for a period of 
time sufficient to allow examination of all joints, connections and high 
stress areas.

[CGD 95-028, 62 FR 51220, Sept. 30, 1997]

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