Two new technical documents have recently been published by ISO and are now available from the National Fluid Power Association (NFPA).

ISO 1219-2:2012 (supersedes ISO 1219-2:1995) Fluid power systems and components - Graphical symbols and circuit diagrams - Part 2: Circuit diagrams (second edition). This establishes the main rules for drawing hydraulic and pneumatic circuit diagrams using graphical symbols drawn in accordance with ISO 1219-1. It also applies to circuit diagrams relating to systems relating to cooling systems, lubrication systems and systems of technical gases used in conjunction with fluid power applications. This part of ISO 1219 also includes examples of circuit diagrams.

ISO 1219-2 lays down the rules for creating circuit diagrams for fluid power systems. Circuit diagrams facilitate understanding of the design and description of a system so that confusion and error can be avoided during planning, manufacturing, installation and maintenance.

ISO 6953-3:2012 Pneumatic fluid power — Compressed air pressure regulators and filter-regulators — Part 3: Alternative test methods for measuring the flow-rate characteristics of pressure regulators. This part of ISO 6953 specifies alternative test methods for determining the flow-rate characteristics of pneumatic fluid power components that can be applied when:

  • the pressure regulation dynamics of a component under test are rapid enough to be negligible, compared to the response of pressure changes during charge and discharge tests;
  • the pressure response does not show any overshoot or any oscillating behavior.

This part of 6953 applies to the following components:

  • compressed air pressure regulators and filter-regulators according to ISO 6953-1,
  • electropneumatic pressure control valves according to ISO 10094,
  • other components such as relief valves.

The standard does not cover pressure regulation characteristics, which are dealt with in ISO 6953-2. ISO 6953-3 benefits users and manufacturers by facilitating comparisons of compressed air pressure regulators and filter-regulators by standardizing test methods and the presentation of test data related to flow-rate characteristics.

Both standards can each be purchased for $178 or $141 for members.

Visit www.nfpa.com for more details.