Agenda Item 650-567
Consistent Chime Projection
Rev 1 - 07/11/2003 Ballot for Fall 2003
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Agenda Item: 650-567Title: /
Consistent Chime Projection
Date: / 07/11/03Contact: / Ken Erdmann
1109 W. Main Parkway
Catoosa, OK 74015
Ph 918-379-6434
Fax 918-379-6450
Cell 918-640-1511
Purpose: / The purpose of this agenda item is to provide a consistent chime for tanks with bottoms or annular rings. This agenda item will also address outside corner welds for tanks with low type reinforcement pads or thickened inserts.
Source: / Inquiry 650-I-38/02
Revision: / 1
Impact: / This agenda item will improve the consistency of the standard and will address a potential problem with the current standard.
Rationale: / The current standard contains varying chime requirements for tank bottoms versus tank annular rings. Additionally, the chime for a bottom is referenced from the toe of the corner weld attaching the bottom to the shell while the annular ring chime is referenced from the outside of the shell. No chime allowance is mentioned to address thickened inserts or low type reinforcement pads.
The current standard could be allowing lesser corner welds in the area of low type pads than the standard would allow.
Proposed Changes:
Agenda Item 650-567
Consistent Chime Projection
Rev 1 - 07/11/2003 Ballot for Fall 2003
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Currently not addressed
Current 3.4.2
Bottom plates of sufficient size shall be ordered so that, when trimmed, at least a 25 mm (1 in.) width will project beyond the outside edge of the weld attaching the bottom to the shell plate.
Add New 3.1.5.7 d.
Shell-to-bottom fillet welds around low type reinforcement pads shown in Figure 3-5 Details a and b or around shell insert plates that extend beyond the outside surface of the adjacent tank shell shall be sized as required by paragraphs a, b or c above. Additionally, the bottom or annular ring chimeplates shall be sufficient to provide a minimum 13 mm (1/8 2 in.) from the toe of the shell-to-bottom fillet weld to the outside edge of the bottom or annular plates chime.
Proposed 3.4.2
Bottom plates of sufficient size shall be ordered so that, when trimmed, at least a 50 mm (2 in.) width will project outside the shell.
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Agenda Item 650-567
Consistent Chime Projection
Rev 1 - 07/11/2003 Ballot for Fall 2003
Page 1 of 1
Notes:
Rev. 1 07/11/03 Changes -
The changes were based on a desire to have 1 inch of chime past the outside surface of a thickened insert or low type pad. With this 1 inch projection and the largest outside fillet weld of 1/2" this would result in the 1/2" projection past the thickened insert or low type pad fillet in place of the 1/8" that was in the original proposed ballot.
Consideration should be given to adding something to API-653 to address how this applies to existing bottoms with new inserts or low type pads.
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