INSPECTION AND WELDING OF CIRCULAR SEAM (CIR-SEAM)
As we discussed earlier
Long Seam Set-Up and Inspection the circular seam is also similar lightly in
inspection point of view. Circular Seam is called Cir-Seam. We can check the Cir-Seam
of individual shell or number of shells combined in fabrication of pressure
vessel or in column.
The following parameters checked
during inspection of individual Cir-Seam as,
1) Identification mark on plate of respective
Cir-Seam.
2) Profile Verification with template.
3) NDT of Long Seams Carried out or not.
4) Weld Edge Preparation.
5) DPT (Dye Penetration Testing)/ MPT (Magnetic
Particle Testing carried out or not as per client requirement.
6) Orientation marking as per engineering
drawings or not.
7) Off-set within tolerance limit or not.
8) Ovality checking.
9) PTC (Production Test Coupon) Results only
if applicable.
PIC.01: Checking of Off-set During inspection of Cir-Seam.
During
inspection of Cir-Seam following parameters considered,
A) Align the two pairs of rotators and one of
them is drive unit.
B) Match the orientation of all offered shells
with engineering drawing by rotating the shell sections.
C) Checking of overall length of offered Shell sections
as Cir-Seams.
D) Keep proper full off-set in between each
Cir-seams.
E) Lock the equipment at main Degrees (Orientation
so that checking for orientation as per engineering drawing is easy)
F) Checking of alignment of offered seams at
main four orientations.
G) Checking of visual inside outside of equipment,
remove all internal cleats.
H) Verification of Weld Edge Preparation (WEP),
Root Face and Root Gap as per drawing engineering drawing or not.
I) Check
PTC requirement
Following table
shown maximum Off-Set in Butt Weld for Cir-Seam.
PIC.02
Following table
shown Reinforcement limit in Butt Weld for Cir-Seam.
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