Page 391 - Reciprocating Compressors Operation Maintenance

376 Reciprocating Compressors: Operation and Maintenance

3. Lock the belt wheel or block crankshaft to prevent rotation.
4. When servicing the cylinder end, drain the water from cylinder
jackets.
5. Never install a shut-off valve between the compressor and air
receiver or aftercooler unless a safety valve is put in the piping
between the valve and compressor.
6. Do not attempt to service any parts without first relieving the entire
system of air or gas pressure.

MAINTENANCE HINTS

1. Never pull the piston rod through the oil scraper rings or piston rod
packing rings.
2. Never use a chisel or other sharp instrument to open any joint
between piston rod packing cups.
3. Never use kerosene, gasoline, or any contaminating safety solvent
as a cleaning agent.
4. Never start the compressor after cylinder overhaul without first bar-
ring the unit through one complete revolution to be certain every-
thing is free.
5. Never fail to shut down to investigate a new or unusual noise or
knock.
6. Never insert hands into a cylinder or running gear until the driver is
inoperative and the crossheads have been blocked to prevent rotation.
7. Never use a pipe wrench on any part of a piston rod.

Compressor valve installation is critical to safety because many com-
pressors will accept suction or discharge valves in all valve ports. Valve
installation must ascertain that a suction valve is not installed in a dis-
charge port, or a discharge valve is not installed in a suction port.

NONINTERCHANGEABLE VALVES

Generally, suction and discharge valves are the same and can be used
in either port by merely turning them over. If care is not taken, a suction
valve could be put in a discharge port in the wrong flow direction thereby
causing pressures in the cylinder to build up to a dangerous level.