Page 193 - Compression Machinery for Oil and Gas
P. 193
182 SECTION II Types of Equipment
as the same numerical values are reasonably valid over all machine speeds and
vibration frequencies.
Acceptable velocity Marginal velocity
Part limit mm/s rms limit mm/s rms
Foundation 3.0 4.5
Frame top 8.0 12.0
Cylinder lateral 13.0 19.5
Cylinder rod 16.0 24
Damper 19.0 28.5
Piping 19.0 28.5
The foundation would be considered to be the top of the foundation at the
foundation compressor base interface. Frame top should be considered the
solid part of the frame which is directly linked back to the compressor bearings
and direction is the piston rod direction. Cylinder lateral is the side of the cyl-
inder measuring in the axis of the crankshaft. Cylinder rod is the end of the
cylinder measured in the piston rod direction. Dampers are the pulsation bot-
tles in any direction. Piping means gas piping. Acceptable and lower levels are
considered good values for normal running measurements. Above acceptable
to marginal levels are considered high and some evaluation needs to be made
as to whether these are acceptable or if remediation is necessary. Above mar-
ginal values are considered unacceptable and shutdown or remediation is
necessary.
Key Guidance From Standards
Oil and gas industry reciprocating compressor standards and some comments
about each:
l API Standard 618 “Reciprocating Compressors for Petroleum, Chemical,
and Gas Industry Services,” Fifth Edition published December 2007. A
Sixth Edition is in development at this time.
Edition history:
First Edition: April 1964 (34 pages)
Second Edition: July 1974 (39 pages)
Third Edition: February 1986 (109 pages)
Fourth Edition: June 1995 (165 pages)
Fifth Edition: December 2007 (190 pages)
Sixth Edition: Pending Publication
l API Specification 11P “Specification for Packaged Reciprocating Compres-
sors for Oil and Gas Production Services,” Second Edition published
November 1989. The First Edition was published February 1975. This Sec-
ond Edition is no longer available for purchase from API and not supported
by API.
