1、 1 API/IP 1581 Specifications and qualification procedures for aviation jet fuel filter/separators,5th Edition Addendum 20th December 2006 Page 3 2.1.2 is amended to read:A filter/coalescer is an element that is capable of removing dirt and of coalescing fine droplets of water in the fuel to sizes t
2、hat can be removed in the filter/separator vessel.Filter/coalescers are classified as Type S,Type S-LD(low dirt)and Type S-LW(low water)according to the amount of dirt and water the elements are capable of removing as defined in Section 2.3.Page 5 Add new Section 2.3.4 and renumber existing Sections
3、 2.3.4,2.3.4.1 and 2.3.4.2 to Sections 2.3.5,2.3.5.1 and 2.3.5.2 2.3.4 Type S-LW filter/separators Type S-LW filter/separators(also known as coalescer/separators)shall only be used for mobile applications where minimal amounts of water can be expected in the jet fuel.The qualification requirements f
4、or Type S-LW filter/separators are:(a)The Type S-LW filter/separator shall be able to maintain rated flow when it is contaminated with particulate to the level specified in Section 4 without the contamination in the effluent fuel exceeding the level specified in Section 3.1.1.(b)The Type S-LW filter
5、/separator shall be able to effectively remove water from fuel without exceeding the effluent free-water levels specified in Section 3.1.1 when 0,5%water is added according to the procedures specified in Section 4.Page 5 2.4.1.2(a)is amended to read:(a)Filter/separators qualified by testing to Categ
6、ory M100 do not qualify for Category M.Separate tests shall be conducted independently of any Category M100 tests to qualify filter/separators for Category M.Page 5 2.4.2 is amended to read:Filter/separators qualified as Type S by testing also qualify as Type S-LD and S-LW at the tested flow rate an
7、d conditions.Copyright American Petroleum Institute Provided by IHS under license with API No reproduction or networking permitted without license from IHS 2 Page 9 Add new second paragraph to 3.2.2.7 before the Note:Water shall drain freely from the entire vessel and sump.A sump having a flat,level
8、 base does not meet this requirement.Vessel designs(i.e.lid sealing schemes)that create void spaces that can trap water do not meet this requirement.Page 9 3.2.2.14 is amended to read:Unless special installation conditions require otherwise,access to the elements shall be provided by a hinged or piv
9、oted vessel cover.The use of swing bolts is recommended to facilitate quick access to the interior of the vessel.To permit access to the far end of a vertical vessel for maintenance purposes,a vertical vessels length-to-diameter ratio shall be limited by the following expressions,unless otherwise sp
10、ecified by the purchaser:For vessels 61 cm(24 inch)diameter:L/D 1,75 For vessels 61 cm(24 inch)diameter:L/D 2,5 where:L is the distance from the deck plate or manifold to the lid opening,and D is the inside diameter of the vessel.Page 20 The last paragraph of 4.4.5.4 is amended to read:Although norm
11、ally filter/separator vessels are qualified to remove 3%water,vessels may exist in conditions where there is limited potential for water contamination(e.g.systems with independent water detection)and less performance may be acceptable.For such applications,filter/coalescer and separator systems cans
12、 be qualified as Type S-LW by reducing the water injection rate during qualification to 0,5%by volume instead of 3%.Vessels so qualified should be clearly marked as Type S-LW.For more information see Annex B.Page 40 Add new Annex B:ANNEX B INFORMATIVE ANNEX This Annex is provided for information.The
13、 following are not mandatory requirements of this specification.This specification details laboratory testing requirements and acceptable levels of selected aspects of performance for three Types of filter/coalescer and separator systems:Type S,S-LD and S-LW.A premise of API 1581 3rd edition was tha
14、t fuel should be cleaner as it passed through the distribution system thus lower levels of dirt and water removing performance were acceptable as the fuel approached aircraft.This premise was reviewed in the process of preparing API/IP 1581 4th edition and rejected as inappropriate.The specification
15、 writers selected Class B systems as offering a dependable level of dirt and water removal performance and derived the requirements for 4th/5th edition Type S systems from 3rd edition Class B systems.Systems of two other Types are defined by API/IP 1581 5th edition as amended:Type S-LD(low dirt)and
16、S-LW(low water).S-LD systems are envisioned for use in historically clean systems and in applications immediately downstream of microfilters where elements are essentially never changed out because of high differential pressure.The premise for this Copyright American Petroleum Institute Provided by IHS under license with API No reproduction or networking permitted without license from IHS 3Type was that a more efficient product might be developed if unnecessary dirt holding capacity was relaxed.
