[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: 46CFR54.10-15]

[Page 155]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 54_PRESSURE VESSELS--Table of Contents
 
             Subpart 54.10_Inspection, Reports, and Stamping
 
Sec. 54.10-15  Pneumatic test (modifies UG-100).

    (a) Pneumatic testing of welded pressure vessels shall be permitted 
only for those units which are so designed and/or supported that they 
cannot be safely filled with water, or for those units which cannot be 
dried and are to be used in a service where traces of the testing medium 
cannot be tolerated.
    (b) Proposals to pneumatically test shall be submitted to the 
cognizant Officer in Charge, Marine Inspection, for approval.
    (c) Except for enameled vessels, for which the pneumatic test 
pressure shall be at least equal to, but need not exceed, the maximum 
allowable working pressure to be marked on the vessel, the pneumatic 
test pressure shall be at least equal to 1.25 times the maximum 
allowable working pressure to be stamped on the vessel multiplied by the 
lowest ratio (for the materials of which the vessel is constructed) of 
the stress value ``S'' for the test temperature of the vessel to the 
stress value ``S'' for the design temperature (see UG-21 of the ASME 
Code). In no case shall the pneumatic test pressure exceed 1.25 times 
the basis for calculated test pressure as defined in UA-60(e) of the 
ASME Code.
    (d) The pneumatic test of pressure vessels shall be accomplished as 
follows:
    (1) The pressure on the vessel shall be gradually increased to not 
more than half the test pressure.
    (2) The pressure will then be increased at steps of approximately 
one-tenth the test pressure until the test pressure has been reached.
    (3) The pressure will then be reduced to the maximum allowable 
working pressure of the vessel to permit examination.
    (e) Pressure vessels pneumatically tested shall also be leak tested. 
The test shall be capable of detecting leakage consistent with the 
design requirements of the pressure vessel. Details of the leak test 
shall be submitted to the Commandant for approval.
    (f) After satisfactory completion of the pneumatic pressure test, 
the vessel may be stamped in accordance with Sec. 54.10-20. A marine 
inspector shall observe the pressure vessel in a loaded condition at the 
first opportunity following the pneumatic test. The tank supports and 
saddles, connecting piping, and insulation if provided shall be examined 
to determine if they are satisfactory and that no leaks are evident.
    (g) The pneumatic test is inherently more hazardous than a 
hydrostatic test, and suitable precautions shall be taken to protect 
personnel and adjacent property.