bmoorthy
Mechanical
- May 29, 2003
- 457
2 identical ball valves, all CS body, bonnet, SS 316 Ball, SS 316 Stem, SS 316 Seat ring with soft seat insert, turnion, 718 springs were procured. All from same manufacturer (One of the top world renowned valve manufacturer). 10" 300 Rating, ISO 17292 (Tested to ISO 12266 and ISO 15848-2).
A) One valve is still in stores (Project stores, not installed in the piping) in reasonably controlled atmosphere,
B) One valve was installed on the piping and piping hydro test (Done 24 hours prior to opening) and piping leak test completed. Due to some modification in near by location, the valve had to be dismounted (Subsequnetly we intend to perform leak test of the line again).
1) The following is the observation made after dismounting of the valve (B)
Inside surface of the valve was still wet (but no stagnant liquid), jut wet.
Color of inside surface was in rust color. Rust colored thin wet power (appears to be slurry that occurs after hydro test on CS surfaces)
Rust coloured drops were seen on the inside surface of the ball bore
When a white cloth was used to swab the inside surface, the rubbed portion of the cloth became wet and was rut in color.
2) cover of the valve that is in the stores was opened and the inside surface see, the surface was blackish in color (Appear to have been protected by some kind of rust preventive). small discontinuities were seen on the rust protection and in those location the steel surface appears to have commencement of dots rust.
client has isued an non conformance stating that the valve surfaces have started to rust.
I called the manufacturer to understand the consequence of occurance of natural rust as a consequence of Carbon steel surface on the functionality of the valve and leak tightness. Manufacturer says this is a non issue blown out of proportion.
In order to give objective reply i searched for any standard that defines rust types and its effects (classification) and definition of threshold. Any standard will do, some starting point for us to have an objective approach on rust in Carbon steel piping and its effect on valves.
Request for some international standards from any industry (not company specific standards)
A) One valve is still in stores (Project stores, not installed in the piping) in reasonably controlled atmosphere,
B) One valve was installed on the piping and piping hydro test (Done 24 hours prior to opening) and piping leak test completed. Due to some modification in near by location, the valve had to be dismounted (Subsequnetly we intend to perform leak test of the line again).
1) The following is the observation made after dismounting of the valve (B)
Inside surface of the valve was still wet (but no stagnant liquid), jut wet.
Color of inside surface was in rust color. Rust colored thin wet power (appears to be slurry that occurs after hydro test on CS surfaces)
Rust coloured drops were seen on the inside surface of the ball bore
When a white cloth was used to swab the inside surface, the rubbed portion of the cloth became wet and was rut in color.
2) cover of the valve that is in the stores was opened and the inside surface see, the surface was blackish in color (Appear to have been protected by some kind of rust preventive). small discontinuities were seen on the rust protection and in those location the steel surface appears to have commencement of dots rust.
client has isued an non conformance stating that the valve surfaces have started to rust.
I called the manufacturer to understand the consequence of occurance of natural rust as a consequence of Carbon steel surface on the functionality of the valve and leak tightness. Manufacturer says this is a non issue blown out of proportion.
In order to give objective reply i searched for any standard that defines rust types and its effects (classification) and definition of threshold. Any standard will do, some starting point for us to have an objective approach on rust in Carbon steel piping and its effect on valves.
Request for some international standards from any industry (not company specific standards)
