[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: 46CFR59.10-10]

[Page 283-284]
 
                           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. 59.10-10  Corroded surfaces.

    (a) Corroded surfaces in the calking edges of circumferential seams 
may be built up by welding to the original thickness under the following 
conditions:
    (1) The thickness of the original metal to be built up between the 
rivet holes and the calking edge shall not be less than one-fourth of 
the diameter of the rivet hole, and the portion of the calking edge to 
be thus reinforced shall not exceed 30 inches in length in a 
circumferential direction.
    (2) In all repairs to circumferential seams by welding, the rivets 
shall be removed over the portions to be welded for a distance of at 
least 6 inches beyond the repaired portion.
    (3) After repairs are made the rivet holes shall be reamed before 
the rivets are redriven.
    (b) It is not permissible to build up or reinforce a grooved or 
corroded area of unstayed internal surfaces by means of welding, except 
that widely scattered pit holes may be built up by welding.
    (c) Where external corrosion has reduced the thickness of flat 
plates around hand holes to an extent of not more than 40 percent of the 
original thickness and for a distance not exceeding 2 inches from the 
edge of the hole, the plate may be built up by welding.
    (d) Where stayed sheets have corroded to a depth not exceeding 40 
percent of their original thickness, they may be reinforced or built up 
by welding. Where the staybolts are fitted with riveted heads, the 
staybolts in the reinforced area shall be renewed in accordance with the 
provisions of Sec. 52.20-15 of this subchapter, but where the staybolts 
are fitted with nuts, the nuts may be removed and after reinforcing has 
been applied, collars may be welded around the staybolts in lieu of the 
nuts. Such reinforced areas shall not exceed 400 square inches nor more 
than 30 inches in one direction. Two such areas in any one plate may be 
reinforced: Provided, that the distance between the reinforced surfaces 
is not less than 30 inches.
    (e) When the corroded portion of a staybolted surface exceeds 400 
square inches, it is permissible to make repairs by cutting out the 
defective portion and replacing it with a new plate, the edges of the 
new plate to be welded in position. In such cases, new staybolts shall 
be fitted in accordance

[[Page 284]]

with the requirements of Sec. 52.20-15 of this subchapter and where 
welding is performed through a line of staybolts, welded collars as 
required by Figure 52.01-3 of this subchapter shall be used to attach 
the staybolts.
    (f) Eroded seams of welded pressure vessels may be repaired by 
rewelding the wasted portion. The wasted section of the seam shall be 
excavated sufficiently by grinding, flame or arc gouging or chipping to 
ensure proper weld penetration. Rewelded seams shall be nondestructively 
tested in accordance with section VIII, ASME Code.