LPSC (M)/PT/04/2013-14 (sl No 3) - ISRO

5.2 External surface: The external surface shall be subject to extra shot
blasting to achieve surface condition as per “Preparation grade B Sa 2½”
and surface finish to “15µm Ra”. The treatment shall be followed by
painting with 2 coats of anti-corrosion paint of 70µm layer thickness.
Surface finish of vessels after shot blasting shall be measured and details
may be provided. The painting shall be French grey.
6. End connections:
Flanged ends on both sides as given in Drg No. SPTF/HPC/01/2013
7. Marking:
The cylinder shall be stamped with permanent and clearly visible
identification marks at an accessible location by steel stamps. The details
such as water capacity, filling pressure at 15 0 C, hydraulic test pressure,
material of construction, manufacturer’s serial number, date of inspection
and inspector’s stamp shall be marked.
8. Tests:
The following tests shall be performed.
Material test for physical and chemical properties.
Hardness test.
Magnetic particle examination on the dished ends.
Liquid penetrant examination on the bore of the dished ends.
Internal and external surface examination.
Tare mass measurement.
Water capacity measurement.
Hydraulic stretch test as per DOT 173.34 (the hydraulic test pressure
shall be as per the code but not less than 1.5 times the filling
pressure at 15 0 C)
Ultrasonic test for flaw detection.
Dimensional check.
Wall thickness measurement by ultra sonic probe at identified points
(The location of the measurement points shall be either permanently
marked on the gas cylinders or sketched on a drawing with reference
to a fixed point on the cylinder)
Dye penetrant test at all the weld joints of the flanges.
Hydro test of manifold assembly at 1.5 times of MAWP.