Page 174 - Machinery Component Maintenance

156 Machinery Component Maintenance and Repair
After hydrostatic tests have been made and the pipe sections have been
cleaned as thoroughly as possible on the inside, the piping should be
pickled by this procedure:
1. Pickle for 14 hours with hydrochloric acid. Circulate the acid con-
tinuously by means of a small pump. Use a five to 12 percent solu-
tion of hydrochloric acid, depending upon the condition of the pipe.
2. Neutralize with caustic.
3. Blow hot air through for several hours.
4. Fill with mineral seal oil and drain.
5. Blow out with hot air.
6. Pipe is now ready to use. If the pipe section is not to be assembled
immediately, seal the ends tightly until ready for use. Then, before
installation, pull through a swab saturated with carbon tetra-
chloride.

Even though this procedure has bccn carefully followed; on reciprocat-
ing compressor piping, a temporary filter (such as Type PT American
Filter, Type PS Air-Maze, or equal) should be installed in the suction line
to the suction bottle to remove particles 230 microns* (.009 in. diameter)
or larger. Provision must be made in the piping to check the pressure
drop across the filter and to remove the filter cell for cleaning. Filter cell
should be removed and left out only when the inlet line is free of welding
beads, pipe scale, and other extraneous matter.
On large piping (where a man can work inside), the pickling procedure
can be omitted if the piping is cleaned mechanically with a wire brush,
vacuumed and then thoroughly inspected for cleanliness. Time and trou-
ble taken in the beginning to ensure that the piping is clean will shorten
the break-in period, and may save a number of expensive shutdowns.

Pickling Procedure For Reciprocating Compressor Suction Piping
(Method I)
General Recommendations

1. The job should be executed by experienced people.
2. Operators must wear adequate safety equipment (gloves and
glasses).
3. Accomplish entire pickling operation in as short a time as possible.

* 140 microns (0.0055 in. diameter) for nonlubricated cylinders.