Volume-II of IV - GAIL

MECON LIMITED
Delhi
PROCESS & PIPING
DESIGN SECTION
TECHNICAL SPECIFICATION
FOR
CHECK VALVES
TECHNICAL SPECIFICATION NO. : MEC/TS/05/62/004 REV-2 Page 4 of 8
4.8 An arrow indicating the direction of flow shall be embossed or cast on the body
of all valves.
4.9 All welds shall be made by welders and welding procedures qualified in
accordance with the provisions of ASME Section IX. The welding and repair
welding procedure qualification shall include impact test and shall meet the
requirements of clause 3.4 of this specification.
4.10 Repair by welding is permitted for cast body valves subject to written approval
by Purchaser and shall be carried out as per ANSI B16.34. Repair shall be
carried out before any heat treatment of casting is done.
5.0 INSPECTION AND TESTS
5.1 The Manufacturer shall perform all inspection and tests as per the requirements
of this specification and the relevant codes, prior to shipment at his works. Such
inspection and tests shall be, but not limited to, the following :
5.1.1 All valves shall be visually inspected.
5.1.2 Dimensional check on all valves shall be carried out as per the Purchaser
approved drawings.
5.1.3 Chemical compositions and mechanical properties shall be checked as per
relevant material standards and this specification, for each heat of steel used.
5.1.4 a) Where applicable, the body castings of valves shall be radiographically
examined on 100% of the surface of critical areas as per ANSI B16.34.
Procedure and acceptance criteria shall be as per ANSI B16.34.
b) Where applicable, valve body made by forging and plate components
shall be ultrasonically examined in accordance with procedure and
acceptance standard of Annexure E of ANSI B16.34.
c) The extent of radiography/ ultrasonic examination shall be as follows :
D:\old data\FATEH\MP Region\Kailaras\Tender RFQ\Check Valve\Check Valves - 004 - TS-R2.doc
ANSI class 150 - All sizes - Nil
ANSI class 300 - < DN 400mm (16”) - Nil
> DN 450mm (18”) - 100%
ANSI class 600 - All sizes - 100%