MSI LT VALVE TECHNICAL MANUAL
Revision D
April 03, 2014
62
8.2 SANDING TIPS
When repairing a MSI plug valve, the following basic guidelines can help
you ensure a successful hydrostatic test of the reassembled valve.
Sanding is necessary to repair blemishes from the sealing surfaces of parts.
Sanding of scratches, dings, and pitting should always be done with 600 grit
sanding cloth that is well lubricated with water or solvent. When sanding
sealing surfaces, it is VERY important to avoid sanding in one spot
continuously; sand evenly across the entire sealing surface. Sand scratches
by moving the sandpaper around the plug, not up and down, along the
length of the plug. If scratches cannot be removed utilizing this technique,
replace the parts. If raised edges or dings in non-sealing areas are too large
to be sanded effectively, you may use a rotary flapper-type sanding wheel.
It is very important that you do not remove any material other than the
actual raised edge. Do not remove any of the base material or you may
permanently damage the valve and render it unsafe for use.