PACKAGE : I Bid Document VOLUME : II - Public Health Engineering

Parameters:
Rating - 10 Bar (PN 1.0)
Shop Testing Witnessing:
Seat leakage test - 10 bar (1.0 M Pa)
Body Hydrostatic test - 15 bar (1.5 M Pa)
Back Seat Leakage test - 15 bar (1.5 M Pa)
12.5 Valve bodies.
a. Castings:
The structure of the castings shall be homogeneous and free from non-metallic
inclusions and other injurious defects. All surface of casing which are not
machined shall be smooth and shall be carefully filed to remove all foundry
irregularities.
b. Forgings:
All major stress bearing forgings shall be made to a standard specification, which
shall be submitted if required to the Engineer for approval before work is
commenced. Forgings shall be subjected to non-destructive tests to detect flaws if
any. Forgings shall be heat treated for the relief of residual stresses.
c. Workmanship:
Workmanship and general finish shall be of first class commercial quality and in
accordance with best workshop practice.
All similar items of the valve and their component parts shall be completely
interchangeable. Spare parts shall be manufactured from the same materials as the
originals and shall be accurate and to specified tolerances so that replacements
made to manufacturer’s drawings may be readily installed.
All parts, which can be worn or damaged by dust, shall be totally enclosed in dust
proof housings.
d. Protective coating:
Protective coating shall comply with IS: 14846 - 2000.
GTS : General Technical specification. Page 94