BS ISO 3968:2017

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols
5 Operational characteristics
   to be tested
6 Filter to be tested
7 Test equipment
8 Measurements
9 Procedure
10 Presentation of results
11 Identification statement (reference to this document)
Annex A (informative) - Introduction to the power loss
        equation and method to calculate
Bibliography

Describes a procedure for evaluating differential pressure versus flow characteristics of hydraulic filters and constitutes a basis for agreement between the filter manufacturer and user.

This document specifies a procedure for evaluating differential pressure versus flow characteristics of hydraulic filters and constitutes a basis for agreement between the filter manufacturer and user.

It also specifies a method for measurement of the differential pressure generated at different flow rates and viscosities by the relevant parts of a filter assembly, spin-on and any valves contained within the filter which are in the flow stream. The typical types of filter to be tested are as follows:

Type 1: which are spin-on filters in which the replaceable unit does not include a filter head (it might or might not include the element by-pass valve);

Type 2: which are spin-on filters in which the replaceable element is tested together with a filter head (it might or might not include the element by-pass valve);

Type 3: which are filter assembly, usually of the replacement element type, that is the housing (head and bowl) and element.