[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: 46CFR54.10-5]

[Page 153-154]
 
                           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. 54.10-5  Maximum allowable working pressure (reproduces UG-98).

    (a) The maximum allowable working pressure for a vessel is the 
maximum pressure permissible at the top of the vessel in its normal 
operating position at the operating temperature specified for that 
pressure. It is the least of the values found for maximum allowable 
working pressure for any of the essential parts of the vessel by the 
principles given in paragraph (b) of this section and adjusted for any 
difference in static head that may exist between the part considered and 
the top of the vessel. (See UA-60 (a) of the ASME Code.)
    (b) The maximum allowable working pressure for a vessel part is the 
maximum internal or external pressure, including the static head 
thereon, as determined by the rules and formulas in this Division (ASME 
Code), together with the effect of any combination of loadings listed in 
UG-22 of the ASME Code (see Sec. 54.01-30) which are likely to occur, 
for the designated coincident operating temperature, excluding any metal 
thickness specified as corrosion allowance. (See UG-25 of the ASME 
Code.)
    (c) Maximum allowable working pressure may be determined for more 
than one designated operating temperature, using for each temperature 
the applicable allowable stress value.

    Note: Table 54.10-5 gives pictorially the interrelation among the 
various pressure

[[Page 154]]

levels pertinent to this part of the regulations. It includes reference 
to section VIII of the ASME Code for definitions and explanations.

 Table 54.10-5--Pictorial Inter-Relation Among Various Pressure Levels With References to Specific Requirements
                                                       \1\
----------------------------------------------------------------------------------------------------------------
                                                                                       Pressures upon which
   Pressure differential, psi \2\       Test pressures \3\    Relief device pressure    relief device flow
                                                                     settings            capacity is based
----------------------------------------------------------------------------------------------------------------
                                     Burst proof test (UG-    ......................
                                      101(m) of ASME Code).
                                     Yield proof test (UG-    ......................
                                      101(j) of ASME Code).
                                     Standard hydrostatic     ......................
                                      test (UG-99 of ASME
                                      Code).
                                     .......................  ......................  Fire exposure, 120%
                                                                                       MAWP.
                                     Pneumatic test (UG-100   ......................
                                      of ASME Code).
                                     .......................  Rupture disk burst
                                                               (Sec. 54.15-13).
                                     .......................  ......................  Normal, 110% MAWP.....
------------------------------------
                                     Maximum allowable        Maximum allowable       Maximum allowable
                                      working pressure         working pressure        working pressure
                                      (MAWP), UG-98 and UA-    (MAWP), UG-98 and UA-   (MAWP), UG-98 and UA-
                                      60(a) of ASME Code.      60(a) of ASME Code.     60(a) of ASME Code.
------------------------------------
                                     Design pressure, UG-21,  Design pressure, UG-21  Design pressure, UG-21
                                      and UA-60(b) of ASME     and UA-60(b) of ASME    and UA-60(b) of ASME
                                      Code.                    Code.                   Code.
                                     .......................  Safety or relief value
                                                               setting (UG-133 of
                                                               ASME Code).
                                     Operating pressure (UA-  Operating pressure (UA- Operating pressure (UA-
                                      60(f) of ASME Code).     60(f) of ASME Code).    60(f) of ASME Code).
----------------------------------------------------------------------------------------------------------------
\1\ For basic pressure definitions see Sec. 52.01-3(g) of this subchapter.
\2\ For pressure differentials above 3,000 pounds per square inch (p.s.i.), special requirements may apply.
\3\ For the basis for calculating test pressures, see UA-60(e) of the ASME Code.