pickling pipe

[maytag]

I need some direction from some of you experts. I'm currently trying to start a new hydraulic system-piping is all carbon steel-contractors installed the piping, it was hydro-tested, chemically flushed, pickled, supposedly neutralized and then contractors went to an oil flush and had to meet a NAS 4 cleanliness requirement.
At this point the flushing oil is removed and the owner takes control and we bring our HPU and oil online to circulate-I've been flushing for several days and not gaining any ground as far as cleanliness, still around
NAS 13-15. Can the pickling process/neutralization get screwed up enough to cause the carbon pipe to self-destruct?
It seems like we are generating our own particulates especially those 15-100 micron. During the pickling/neutralization the piping contractor ran the flushing company off and we sat dead in the water for several hours.

Thanks for any and all help,
Tom

 

[ash9144]

What was used to pickle? What was used to neutralize? Where was the process when the system sat idle for hours?

 

[DLite30]

Highly unlikely that there would be a pipe failure due to the pickling compound.

I'm not suprised that you're having a hard time getting to NAS 4 using carbon steel components. It's possible that the laquer finish or preserative coating was not removed from the inside of the fittings, and that is still and will continue to degrade and come loose.

Welding can be also be an on-going cause of problems as well. Where the fittings all stick welded, or better yet did they do a TIG root pass, and weldout with stick?

It's pretty standard to use stainless steel fittings and piping for lubricating oil, especially in high cleanliness hydraulic systems.

 

[unclesyd]

All clean piping installations should start with precleaned and passivated pipe either accomplished on site or purchased. In doing so you essentially eliminate all but the construction debris.
There is some very good information on the Redox site linked below.

http://www.redoxinc.com/about.htm