ISO/DIS 4021

Hydraulic fluid power — Particulate contamination analysis — Extraction of fluid samples from lines of an operating system

General information

40.99   Full report circulated: DIS approved for registration as FDIS   Jun 29, 2026

ISO

ISO/TC 131/SC 6 Contamination control

International Standard

23.100.60   Filters, seals and contamination of fluids

Scope

The preferred method is to extract fluid samples from a main flowline in such a manner that the particulate contaminant in the sample is representative of the fluid flowing at the point of sampling. An alternative method is to extract a sample from the reservoir, but this method should only be used if a suitable sampler is not fitted.

Life cycle

PREVIOUSLY

PUBLISHED
ISO 4021:1992

NOW

IN_DEVELOPMENT
ISO/DIS 4021
40.99 Full report circulated: DIS approved for registration as FDIS
Jun 29, 2026