NBN ISO 20816-8:2021

This document establishes procedures and guidelines for the measurement and classification of
mechanical vibration of reciprocating compressor systems. The vibration values are defined primarily
to classify the vibration of the compressor system and to avoid fatigue problems with parts in the
reciprocating compressor system, i.e. foundation, compressor, dampers, piping and auxiliary equipment
mounted on the compressor system. Shaft vibration is not considered.
This document applies to reciprocating compressors mounted on rigid foundations with typical
rotational speed ratings in the range 120 r/min up to and including 1 800 r/min. The general evaluation
criteria which are presented relate to operational measurements. The criteria are also used to ensure
that machine vibration does not adversely affect the equipment directly mounted on the machine, e.g.
pulsation dampers and the pipe system.
NOTE The general guidelines presented in this document can also be applied to reciprocating compressors
outside the specified speed range but different evaluation criteria might be appropriate in this case.
The machinery driving the reciprocating compressor, however, is evaluated in accordance with the
appropriate part of ISO 10816, ISO 20816 or other relevant standards and classification for the intended
duty. Drivers are not included in this document.
It is recognized that the evaluation criteria might only have limited application when considering the
effects of internal machine components, e.g. problems associated with valves, pistons and piston rings
might be unlikely to be detected in the measurements. Identification of such problems can require
investigative diagnostic techniques which are outside the scope of this document.
Examples of reciprocating compressor systems covered by this document are
— horizontal, vertical, V-, W- and L-type compressor systems,
— constant and variable speed compressors,
— compressors driven by electric motors, gas and diesel engines, steam turbines, with or without a
gearbox, flexible or rigid coupling, and
— dry running and lubricated reciprocating compressors.
This document does not apply to hyper compressors.
The guidelines are not intended for condition monitoring purposes. Noise is also outside the scope of
this document.