[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: 46CFR59.10-20]

[Page 284]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 59_REPAIRS TO BOILERS, PRESSURE VESSELS AND APPURTENANCES--Table of Contents
 
Subpart 59.10_Welding Repairs to Boilers and Pressure Vessels in Service
 
Sec. 59.10-20  Patches in shells and tube sheets.

    (a) Unreinforced openings in the shells or drums of boilers or 
pressure vessels, the diameter of which does not exceed the maximum 
diameter of an unreinforced opening in accordance with Sec. 52.01-100 
of this subchapter may be closed by the use of a patch or plate inside 
the drum or shell and sealed against leakage by welding. Such plates 
shall have a diameter of at least 2 inches larger than the diameter of 
the hole and shall have a thickness equal to the thickness of the plate 
to which it is attached. It is not permissible to insert such patches in 
the shell or head flush with the surrounding plate unless the 
requirements of this subchapter for Class I welded pressure vessels are 
met.
    (b) Portions of tube sheets which have deteriorated may be renewed 
by replacing the wasted portion with a new section. The ligaments 
between the tube holes may be joined by means of welding and staytubes. 
Other acceptable means of lowering the stress on the repaired section 
may be used if in the judgment of the Officer in Charge, Marine 
Inspection, it is necessary.