RIX Industries RIX 2V3B-4.1V Series Operating Instructions And Parts List Manual Download

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MAN-2V3B-4.1V REV (E)

5.10 PISTON

RINGS:

As the piston rings wear, their ability to seal is diminished. Excessive wear will result in lower
compressor capacity, more frequent compressor operation and unnecessary wear on other components.
There is also major risk of damaging cylinder liner if the piston rings wear out completely.

Excess piston to cylinder clearance, caused from either piston or cylinder liner wear, will significantly
decrease ring life. Cylinder bores should be inspected for wear at ring change-outs or other
maintenance actions and measured for wear if ring life has significantly decreased. For maximum ring
life, pistons should not be removed from cylinders prior to ring replacement.

For the 3rd stage floating piston it is recommended that the piston be replaced with the rings as an
assembly at the first change-out, and thereafter as necessary. If undamaged, the original piston can be
re-ringed by the user and kept on hand for the next change-out or scheduled maintenance requirement..

A common indicator of worn rings is low compressor flow. On this 2V3 unit, the 3rd stage is located
over the 2nd stage, and all 3rd stage piston ring blow by passes into the 2nd stage compression area. As
the 3rd stage rings wear, the 2nd stage pressure will tend to increase. Too much ring blow by will cause
the 2nd stage relief valve to pop, at which point the 3rd stage rings must be replaced. If the 2nd stage
rings are also worn excessively, their leak rate may prevent the 2nd stage pressure from increasing. Gas
leaking past either the 1st or 2nd stage rings passes thru the distance piece to atmosphere.

As the 1st or 2nd stages rings wear the cylinder pressures will tend to be lowered. With extreme wear
the compressor will not be able to compress to the design final stage discharge pressure.

Ring life will vary with inlet temperature, discharge pressure, atmospheric operating temperatures and
frequency of start/stop cycles. A low ambient temperature will increase ring life. Frequent start/stop
cycles will reduce ring life. If possible, allow downstream pressure to drop as low as possible before
restarting compressor. This will minimize start/stop cycling of the compressor.

5.11

CYLINDER LINERS:

When ring life deteriorates from normal, cylinder liners should be

checked for scoring or excessive wear. Maximum wear will normally occur in the region 1/3 to 1/2 way
down the bore. A bore gauge is the best way to measure and determine wear. Check diameter at
several depths along the bore for wash-boarding or scoring and hone or replace as required. See chapter
7 for maximum diameters. Cleaning may not be required on normal ring change-outs unless
contaminates are present.

5.12

PISTON ROD OIL SEALS:

The oil seals prevent crankcase oil from leaking into the

distance piece area. If leakage occurs, remove and clean piston rod and replace seals. If scratches are
found on rod surface, refinish per instructions in chapter 7.