PWHT Procedure

1. FAX
FACSIMILE MESSAGE
LPG STORAGE AND TERMINAL FACILITY AT HAMBANTOTA
To LAUGFS From HQC
Attn:
Mr. S.A.Jayasekara
Mr. Kamal Deshapriya
REF. HQSM07-F-HQC/LAUGFS-0854
Fax No. Fax No.
Date 2018-02-24 Page 2
If this transmission is received incorrectly, please call +8610 58675326
Subject: Proposal to remove temporary welding positioned block after PWHT & hydro-test of LPG
spheres.
Dear sirs,
After PWHT of T-1106,T-1107,T-1108,T-1110 and hydro-test of T-1109, during interior scaffolding
erection to conduct further construction work like internal welding seam MT and instrument pipes
installation etc, Subcontractor temporarily tack-welded some positioned blocks to the sphere inner
skin located in the lower part of each sphere in order to root the scaffolding without any clearance
from HQC site team leading to the deviation to ASME standard.
After site investigation and analysis of quality impact on LPG spheres by such kind of
tack-welding method to sphere after PWHT & hydro test, and also thinking of the subsequent
construction activities like blasting and NDT which can be proceeded without any delay, we
proposed following rectification program for your review and approval.
1. One simulation test coupon will be made at jobsite. We will tack-weld one positioned block using
the same way did inside of LPG spheres on one of PTC which is available at jobsite now, then
remove the block by grind wheel manually and carefully without any damage to the PTC material,
after which MT and thickness measurement will be followed around the grinded welding area to
verify if any damage of PTC material occurred or not. Finally this STC will sent to local lab to do
further test to verify no any quality problem to the property of mother material resulted from such
kind of tack-welding.
2. If above test is satisfied, all the tack-welded blocks inside of spheres will be removed as the
same way said in item 1. In future, after all internal work completed we will remove the interior
scaffolding from top of sphere layer by layer, to find and remove all tack-welded blocks observed
one by one under 100% witness by HQC QC staff. If such experiment failed, we will take all the
responsibility and will take further action like to re-do PWHT or hydro test or others required to
meet the quality requirement.

2. FAX
3. Thinking about the site actual situation and based on our experience, we sincerely request that
LAUGFS can allow us continue to conduct the following work:
3.1 Blasting and painting work of T-1109 and T-1110.
3.2 MT work inside of T-1108 and T-1107
3.3 Hydro test of T-1106
3.4 Internal instrument pipes installation of all LPG spheres.
We also apologize for such mistakes happened at jobsite because of management negelance, and
as a lessons learned, we will highlight site management to keep close monitor and effective
communication to all involved parties.
Highly appreciate for your quick feedback and kindly understanding.
Sincerely yours,
Yao Yufei
Project Manager