• Published: August 2024
• REF/ISBN: 978 1 78725 437 4
• Edition: 7th
• Status: Current

This publication specifies minimum laboratory performance, mechanical requirements and qualification test procedures for filter/water separators for use in systems that handle aviation fuel (jet fuel or aviation gasoline) at any point in the supply chain.

It is applicable to filter/water separators intended for use in commercial jet fuel or aviation gasoline  (defined as Category C), military jet fuel (defined as Category M) and military jet fuel containing an additive used to enhance thermal stability (defined as Category M100).

It covers Type S filter/water separators, intended for use where significant levels of free water and particulate matter in the fuel can be expected, Type S-LW where minimal levels of free water can be expected and Type S-M, where minimal levels of free water and minimal levels of particulate matter can be expected (certain into-aircraft applications only)

The main revisions incorporated into the 7th edition of EI 1581 are:

• Inclusion of sustainability requirements as a new Section 3.
• Clarification that within scope is the qualification testing of a coalescer/separator element, that integrates dirt removal, dispersed water coalescence and water droplet separation in one stage (for use only in a single element housing, not in multi-element vessels.
• Deletion of the option to qualify multi-stage systems (filter monitor technology, previously used inside separator elements as a three-stage system, is no longer supported by an EI specification).
• Clarifying that FWS performance assessed by EI 1581 is considered to read-across to FWS performance in any semi-synthetic (or future fully synthetic) jet fuel that meets the requirements of ASTM D7566/D1655 or Def Stan 91-091.

The qualification testing requirements that were included in the 6th edition of EI 1581 have not been significantly amended in this 7th edition. Therefore existing qualifications to the 6th edition are recognised as also meeting the requirements of this 7th edition. This read-across from the 6th to 7th editions applies only to the category tested.