Page 319 - Reciprocating Compressors Operation Maintenance

3O4 Reciprocating Compressors: Operation and Maintenance

THE ANALYST'S ROLE

The major component in a successful troubleshooting effort is the
machinery analyst. The actual analysis of an operating deficiency is per-
formed by the human mind; the analyst is therefore the key ingredient
who makes it all happen.
A good analyst always:

* Deals with facts
* Collects and uses all the facts
* Never jumps to conclusions

Problems with reciprocating compressors generally fall into one of
three broad categories:

• Loss of capacity
• Noise and vibration
• Failure to run

Loss OF CAPACITY

Unless the compressor cannot deliver any pressure at all, this term
usually describes a comparison between the quantity being delivered and
the quantity that should be delivered.
The analyst should determine how a loss of capacity conclusion was
reached. This is of prime importance on plant air machines. All too often,
the addition of new users to the system or even leaks are responsible for
the apparent loss of capacity. The analyst should ask: Did the loss of
capacity occur quickly or is it a problem which gradually became worse?
The answer might indicate whether component failure or the accumula-
tion of wear are likely causes.
The causes and symptoms for capacity loss include the following:

1, Extreme reduction in capacity or no delivery,
* The suction filter could be plugged or the intake line blocked. This,
in effect, would unload the compressor, causing it to act as a vacuum
pump, and actually pump the suction pressure below atmospheric.