API 653 Inspections, Repair, Alterations, and Reconstruction Flashcards
When dismantling a tank, into what size pieces may roof, shell and bottom plates be cut? (API 653-14, Section 10.3.1)
Roof, shell, and bottom plates may be cut into any size
pieces that are readily transportable to the new site for reconstruction.
- When bottom plates are to be reused, how should they be cut? (API 653-14, Section 10.3.2.1)
Bottom plates that will be reused shall be cut by
deseaming of lapwelds; or by cutting alongside of the remaining welds at a minimum of 2 in. away from existing welds, except where cuts cross existing weld seams.
- When roof plates are to be reused, how should they be cut? How should roof supporting structures be dismantled? (API 653-14, Section 10.3.4)
If an entire tank bottom is to be reused in a reconstructed tank, how should the bottom be separated from the existing shell if there is no existing butt welded annular ring?
(API 653-14, Section 10.3.2.
If the bottom is to be used, one of the following
methods is acceptable:
a. The bottom plates may be cut from the shell along a line A-A and line B-B shown in Figure 10-1, scrapping the welds and the bottom plate directly attached to the shell.
b. If the entire bottom is to be reused, the bottom may be cut from the shell on the line C-C leaving the shell with part of the bottom attached.
c. If the tank has an existing butt-welded annular ring, this ring can be left attached to the shell or removed from the shell by cutting out along line B-B or otherwise removing the existing shell to annular ring welds.
- When shell plates are to be dismantled and reused, what are three ways in which they can be cut? (API 653-14, Section 10.3.3.1)
a)
b)
c)
Tank shell plates may be dismantled using one of
the following methods or a combination thereof:
a. Any shell ring may be dismantled by cutting out existing weld seams and the heat affected zone (HAZ) of the weld. For the purpose of this method, the minimum HAZ to be removed will be 1/2 of the weld metal width or 1/4 in., whichever is less, on both sides of the weld seam.
b. Any shell ring 1/2 in. thick or thinner may be dismantled by cutting through the weld without removing the HAZ.
c. Shell rings may be dismantled by cutting vertical and/or
horizontal cuts through the shell a minimum of 6 in. away
from existing welds, except where cuts cross existing welds.
- If shell stiffening rings are removed, what must be done to the temporary attachment points? (API 653-14, Section 10.3.3.2)
The area where temporary attachments are removed shall be ground flush with the shell plate.
- If a tank shell is to be dismantled for reuse with a new bottom, where should the shell be cut from the existing bottom? (API 653-14, Section 10.3.3.3)
The shell shall be cut from the bottom plate along line B-B as shown in Figure IO-. The existing shell-to-bot-
tom weld connection shall not be reused unless the entire bottom is to be reused intact.
- When can the existing shell-to-bottom weld connection be reused in a reconstructed tank? (API 653-14, Section 10.3.3.3)
The existing shell-to-bot-
tom weld connection shall not be reused unless the entire bottom is to be reused intact.
