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UBE GROUP (THAILAND)
ENGINEERING SPECIFICATION
FOR
INSPECTION & TEST OF
VESSELS AND HEAT EXCHANGERS
UBE-D-202
Rev.0 : Sep.30, 2013
Page 4 of 17
ALL RIGHTS RESERVED
THIS DOCUMENT AND ANY DATA AND INFORMATION CONTAINED THEREIN ARE CONFIDENTIAL AND THE PROPERTY OF UBE GROUP. AND
THE COPYRIGHT THEREIN IS VESTED IN UBE GROUP. NO PART OF THIS DOCUMENT, DATA OR INFORMATION SHALL BE DISCLOSED TO
OTHERS OR REPRODUCED IN ANY MANNER OR USED FOR ANY PROPOSE WHATSOEVER, EXCEPT WITH THE PRIOR WRITTEN PERMISSION OF
UBE GROUP.
3.2.4 Surfaces and edges of the materials shall be visually examined for freedom from
injurious defects, such as excessive surface flaw and lamination before the fabrication
proceeds.
3.3 Inspection of Welding
3.3.1 Beveled edges shall be smooth and uniform with dimensions conforming to the welding
procedure specifications. Edges to be ve1ded shall be free from cracks, laminations
and other defects that way adversely affect the welds.
3.3.2 Prior to start of welding of butted joints, edges shall be properly fit-up. Misalignment of
the edges shall be within the code tolerances.
3.3.3 For double welded joints, the backside of the joints shall be cleaned to sound metal
and assured that cracks, slag inclusions or other weld defects have been removed
before backside welding is started.
3.3.4 All welds and area adjacent to the welds shall be visually inspected after completion of
the welding on accessible interior and exterior surfaces. Visual inspection shall show
that the following requirements are met:
(1) Weld reinforcement shall be as required by the applicable codes.
(2) Internal weld protrusion shall not exceed 1.5 mm in height for single butt-
welded joints.
(3) Undercutting shall not exceed 0.3 mm in depth.
(4) Welds shall be free from overlap at the toe of the welds.
(5) Spatter, slag and scale shall be removed.
(6) Crater and jig marks shall be finished smoothly.
(7) No cracks, incomplete penetration and lack of fusion shall be present.
(8) The profile of fillet welds shall be uniform such that leg/throat length is regular
and the surface of welds is slightly convex.
3.3.5. Vessels subject to postweld heat treatment shall, prior to heat treatment, be carefully
inspected by visual and non-destructive methods for defects and checked for
dimensions so as to avoid welding repair after completion of the heat treatment.
3.4 Non-Destructive Examination of Welds
3.4.1 All welded vessels and heat exchangers shall be examined by radiography. The
Radiographic examination procedure shall be in accordance with requirements,
methods and acceptance standards outlined in Table 2 or ASME Section V Article 2.
3.4.2 The degree and extent to be radiographed shall be as indicated on Purchaser's
drawings.
3.4.3 When full radiography is required, butt-welded joints in nozzles with nominal nozzle
size exceeding 10 in. shall be radiographed on their entire length.
3.4.4 When spot radiography is required, each intersection of longitudinal and
circumferential welding seams in the shell and heads of the vessels shall be
radiographed.
3.5 Visual and Dimensional Inspection
3.5.1 Unless otherwise noted, tolerances for pressure vessels shall be in accordance with
Appendix 4.
3.5.2
Unless otherwise noted, "Tolerances for heat exchangers shall be in accordance with
Appendix 5.