Page 422 - Reciprocating Compressors Operation Maintenance

Reciprocating Compressor Calculations 4O7

Existing machine 13" cylinder 9-%" cylinder
Bore, inches 13 9-%
Stroke, inches 16 16
Cylinder design pressure, psi 900 1300
Head end clearance, % 18.4 14.8
Crank end clearance, % 17.1 13.8
2
Suction valve area, per end, in 8.4 5.3
Discharge valve area, per end, in 2 8.4 5.3
Rod size, inches 3-/4 3-%
Maximum rod load, Ibs. 75,000 75,000
Speed, rpm 300 300

Refer to Figure A-10B, Compressor Work Sheet.

Result

Horsepower and rod load are acceptable for this machine.
Capacity = 5820 x 1440/10 6 = 8.4 MMSCFD, which is less than
required. Therefore, process capacity requirements could be decreased to
accept this capacity. Alternatively, clearance could be reduced to increase
e v to bring capacity closer to process requirements.