Api spec 1581 2002 (american petroleum institute)

SPECIFICATIONS AND QUALIFICATION PROCEDURES FOR AVIATION JET FUEL FILTER/SEPARATORS API/IP SPECIFICATION 1581 Fifth edition July 2002 Copyright American Petroleum Institute Reproduced by IHS under lic[.]

Scope

(a) This publication specifies the minimum performance and mechanical requirements and the testing and qualification procedures for aviation jet fuel filter/separators with flow rates ranging up to

(b) This specification defines procedures to qualify filter/separators with and without multi-stages It does not qualify the actual multi-stage device(s).

(c) The inclusion of additive packages in this publication is for testing purposes only and does not constitute acceptance or rejection of these additives in jet fuels by API/IP.

(d) The performance specifications in this publication are for testing purposes only and do not necessarily constitute recommendations by API/IP for specifications in any application of the filter/separators.

(e) Filter/separator systems currently qualified to the

The 4th edition of this specification qualifies products as meeting the performance requirements for the tested category This provision ensures that the performance standards for products claiming compliance with this specification remain unchanged.

General

A filter/separator is a crucial vessel designed to continuously eliminate dirt and water from aviation jet fuel, ensuring it meets the standards required for modern aircraft servicing These systems can be configured either vertically or horizontally and may incorporate multiple stages for enhanced filtration and separation efficiency.

A two-stage system features filter/coalescer and separator elements housed within a vessel Fuel is directed through the filter/coalescer elements into the vessel before passing through the separator elements to exit the vessel.

2.1.1.2 A multi-stage system consists of a two-stage system that contains one or more additional stages.

Additional stages may incorporate qualified devices within each separator element that can halt fuel flow if the filter/coalescer and separator fail to adequately eliminate water These stages may also feature qualified devices within each coalescer element aimed at removing dirt or contaminants during the prefilter and adsorption stages.

A filter/coalescer effectively removes dirt and coalesces fine water droplets in fuel into larger sizes that can be eliminated in the filter/separator vessel These devices are categorized into Type S and Type S-LD (low dirt) based on their dirt removal capabilities, as outlined in Section 2.3.

A separator is an element that prevents water droplets (coalesced by the filter/coalescer) from leaving the vessel in the effluent stream.

For the purpose of this specification, filter/separators are qualified for one or more of the three categories defined in Section 2.2.

6 A qualified device is any device that meets a documented performance specification agreed to by purchaser and manufacturer.

This article utilizes several abbreviations and terms, including cm for centimetre, gallon for U.S gallon, gpm for U.S gallons per minute, kPa for kilopascals (where 1 kPa equals 0.144 psi), l for litre, lpm for litre per minute, mg for milligram, mg/l for milligram per litre, ml for millilitre, mm for millimetre, and pinhole leak.

A structural failure less than 1 mm in size.

Discoloration on the sock of a filter or coalescer may suggest a pinhole leak; however, further investigation is required to determine the concentration in parts per million by volume (ppmv) Additionally, it's important to note that psi (pounds per square inch) is equivalent to 6.95 kPa, and pS/m (picosiemens per meter) is defined as 1 pS/m = 10^{-12} siemens/meter, where 1 siemens equals 1 mho, which is also equal to 1 ohm^{-1}.

= 1 ampere per volt) rated flow:

The rated flow represents the maximum flow rate for a filter/separator system, which is essential for evaluating its performance according to specified standards This flow rate is applicable in field applications and is determined when the system meets all specification requirements.

Categories

2.2.1.1 Category C filter/separators (for commercial aviation fuel) are tested with a fuel containing an additive package in accordance with the procedures described in Section 4.

Category C filter/separators, coalescer/separators, and multi-stage systems are designed for aviation turbine fuels that may include surfactants, but they do not accommodate dispersant additives commonly used in certain military applications to improve the thermal stability of jet fuel.

Category M100 filter/separators, designed for military aviation turbine fuels with enhanced thermal stability, are evaluated using fuel that contains an additive package, including a dispersant to improve thermal stability, following the procedures outlined in Section 4.

Category M100 filter/separators, coalescer/separators, and multi-stage systems are specifically designed for military aviation turbine fuels that contain dispersant additives, which are utilized to improve thermal stability.

2.2.3.1 Category M filter/separators (for military aviation turbine fuels) are tested with fuel containing an additive package used in military fuels in accordance with the procedures described in Section 4.

Category M filter/separators, coalescer/separators, and multi-stage systems are specifically designed for military aviation turbine fuels that include static dissipater additives, metal deactivator additives, anti-oxidants, corrosion inhibitors, and anti-icing additives.

Uses and qualification requirements

Filter/separators can be used at all filtration points in an aviation fuelling system

Type S filter/separators are essential for filtration points where high levels of water and dirt in the product are anticipated The qualification criteria for Type S filter/separators must be met to ensure optimal performance.

(a) The Type S filter/separator shall have a solids holding capacity totalling 1,43 grams per lpm

(19 mg/l for 75 minutes) (5,4 grams per gpm) of rated flow without exceeding the pressure drop and contamination of the effluent fuel as specified inSections 3.1.3.1 and 3.1.1 respectively Note that

DESCRIPTION maximum dirt-holding capacity is not tested in full- scale testing.

The filter/separator must efficiently eliminate water from fuel while maintaining the effluent free-water levels outlined in Section 3.1.1, even when water is introduced following the procedures detailed in Section 4.

Type S-LD filter/separators, also referred to as coalescer/separators, are essential in aviation fuelling systems, particularly in areas where high water content and low dirt levels are anticipated in jet fuel Ideal installation points include directly after a microfilter, which effectively removes dirt, or in areas where dirt levels are manageable without additional filtration The qualification criteria for these coalescer/separators are crucial for ensuring optimal performance.

The Type S-LD filter/separator is designed to sustain its rated flow even when contaminated with particulates, as outlined in Section 4, while ensuring that the contamination in the effluent fuel does not exceed the limits specified in Section 3.1.1.

The Type S-LD filter/separator must efficiently eliminate water from fuel while maintaining the effluent free-water levels outlined in Section 3.1.1, even when water is introduced following the procedures detailed in Section 4.

Multi-stage systems enhance filtration in aviation fuelling systems, particularly at points utilizing two-stage filter/separators These systems provide additional performance and assurance by incorporating pre-filters positioned upstream of filter/coalescers, along with water-absorbing elements.

Water-absorbing elements can provide extra assurance that effluent water remains within the limits outlined in Section 3.1.1 These elements are particularly useful in systems where surfactants or additives could negatively impact filter or separator performance, as well as in fuelling and hydrant servicing operations, where additional precautions are necessary to prevent water contamination in aircraft.

2.3.4.2 The qualification requirement for a multi-stage system is that the filter/separator shall be able to qualify under Section 2.3.2 or 2.3.3 when the multi-stage devices are installed.

Note: This specification applies only to the filter/separator portion of the system No specific level of performance by a multi-stage system is implied by this specification.

Qualification for other category and/or type systems

For single-element testing there is no automatic qualification between categories Qualification for each category shall be established by testing.

(a) Filter/separators qualified by testing to Category M100 also qualify for Category M at the test flow rate and conditions

(b) Filter/separators qualified by testing to Category M also qualify for Category C at the test flow rate and conditions.

Note: Category M100 testing does not qualify to Category C.

2.4.2 Filter/separators qualified as Type S

Filter/separators qualified as Type S by testing also qualify as Type S-LD at the tested flow rate and conditions.

Performance

Contaminants in effluent fuel samples, taken during the specified test procedure and analysed by the specified methods, shall not exceed the following limits:

(a) Total solids content of 0,26 milligrams per litre

(1,0 milligrams per gallon) by ASTM D-2276.

(b) Free water content of 15 ppmv by ASTM D-3240.

(c) Media migration of 10 fibres per litre (38 fibres per gallon).

Any particle in the effluent with a length-to-diameter ratio of 10:1 or moreand a length of 100 microns or more shall be counted as a fibre.

3.1.3.1 Type S filter/separators, as tested in the single- element test, shall hold a quantity of solids greater than or equal to 1,43 grams per litre per minute (19 mg/l x

75 minutes) (5,4 grams per gpm) of rated flow The unit shall hold 67 % of the specified quantity of solids without exceeding a differential pressure of 105 kPa

(15 psi) and shall hold the total specified quantity of solids without exceeding a differential pressure of

Type S-LD filter/separators lack a defined solids holding capacity but are required to withstand differential pressures of 155 kPa (22.5 psi) and 105 kPa (15 psi) as outlined in Sections 4.3.2.6.2 and 4.4.5.3.2 They must maintain these pressures for 45 minutes without allowing particulate contamination in the effluent to exceed the limits specified in Section 3.1.1(a).

3.1.3.3 Multi-stage systems shall meet the performance specifications for Type S or Type S-LD filter/separators, depending on which system is receiving the additional stages.

Two-stage systems must maintain differential pressures below 70 kPa (10 psi) across vessels with new elements and below 42 kPa (6 psi) across the filter/coalescer stage, while operating at rated flow with clean, dry fuel.

Multi-stage systems must maintain a differential pressure across new filter/coalescer elements of no more than 42 kPa (6 psi) when operating at rated flow with clean, dry fuel Additionally, the total differential pressure across the vessel should not exceed the combined limits set for a two-stage system and the new multi-stage devices at their rated flow.

The filter/coalescer elements and sealing devices must endure a differential pressure of 520 kPa (75 psi) without experiencing rupture, seal bypass, or pinhole leaks.

Filter/coalescer and coalescer elements must pass both single-element and full-scale performance tests without exhibiting any signs of media or structural deterioration, including leaks or tears It is important to note that discoloration of the coalescer sock, without additional supporting evidence, does not constitute proof of failure in structural integrity.

Mechanical specifications

The acceptability of a design ultimately depends on satisfactory functioning of the vessel and components during the performance tests described in Section 4.

Filter and separator vessels must be designed and built following the latest edition of Section VIII of the ASME Boiler and Pressure Vessel Code, or according to equivalent regional codes relevant to their intended application.

All metal components in contact with fuel, excluding sensing lines, must be free of zinc, copper, cadmium, and their alloys Acceptable materials for vessels include stainless steel, anodized aluminum, carbon steel, or aluminum treated according to the latest version of MIL-C-5541.

Carbon steel vessels must have an internal coating that is white or light-colored, ensuring durability against fresh and salt water as well as aviation fuels This coating should not deteriorate upon exposure to these elements and must not compromise the quality of the fuel.

Epoxy coatings that meet the latest version of MIL-PRF-4556 or an equivalent specification, along with other purchaser-approved coatings that exhibit equal or better performance, are deemed appropriate.

Vessels may be fabricated from uncoated aluminium upon agreement of purchaser and manufacturer.

3.2.2.2.2 The sensing lines in new installations shall be stainless steel.

3.2.2.3 Vent and pressure relief taps

Each filter or separator must include a tap for a pressure relief valve to manage pressure from thermal fuel expansion Additionally, a connection for an air eliminator should be installed at the highest point of the vessel.

Sample taps must be installed to allow for the collection of influent and effluent fuel samples during fuel flow Each tap should be sufficiently sized to accommodate a minimum 1/4-inch National Pipe Thread probe assembly or a similarly sized assembly, depending on the specific requirements of the intended application.

Pressure taps must be installed to connect suitable pressure gauges or sensors to the filter/separator, allowing for the measurement of inlet pressure and outlet or total differential pressure In multi-stage systems, additional pressure taps are necessary to assess the pressure drops across the filter/coalescer, the separator, and any subsequent stages.

Access must be ensured for the inspection and cleaning of all hard-to-reach areas of the vessel, including sumps and spaces beneath or behind deck plates and manifolds A 10 cm (4 inch) flanged cleanout connection is an acceptable means of access, provided it aligns with the design and construction code, or an alternative method that offers similar accessibility However, any access solutions that necessitate the removal of the vessel's inlet or outlet piping are not acceptable It is essential that access designs are optimized to reduce the volume of deadlegs.

Water drains or sample drains must be installed at the low points of both the inlet and outlet compartments, as well as the deck plate To meet this requirement, welded half-couplings with a diameter of 19 mm (0.75 inch) and equipped with pipe plugs are recommended For effective drainage, these drains should extend from the bottom of the sump collection area, and deck mounting plates should maintain a minimum positive slope of 3% to ensure complete removal of water.

The sump must be designed to ensure that weld ridges or distortions do not obstruct the drainage of accumulated water and debris during standard draining procedures.

Note: Sump flooding can result in the transmission of water downstream Systems/procedures should recognize this possibility and be designed accordingly e.g see Sections 3.2.5.2-3.

3.2.2.8 Drain lines, sample lines, and vents

All drain lines, sample lines, and vents shall be piped to discharge in a manner that minimizes the risk of injury to personnel and damage to the environment.

3.2.2.9.1 A permanent stainless steel or non-ferrous metal nameplate shall be securely attached to the vessel.

The nameplate shall include at least the following information:

(a) The manufacturer’s name and address.

(b) The vessel’s serial number and model number.

(d) The design code of the vessel.

(e) The design pressure for the vessel.

(f) The maximum allowable differential pressure across the deck plate.

The sump volume is defined as the capacity that triggers a water defense system when it is available, or alternatively, it refers to the volume up to the lowest separator stool, filter/coalescer stool, or element, depending on which is smaller.

(h) The vessel cover gasket material and part number.

3.2.2.9.2 In addition to 3.2.2.9.1, a securely attached removable plastic or metal nameplate shall be provided with the following information:

(a) The vessel’s serial number and model number.

(b) The vessel’s API/IP category and type classifica- tion.

(c) The vessel’s rated capacity for jet fuel.

(d) The count and model numbers of the coalescer and separator elements.

(e) The manufacturer’s recommended element-change pressure differential.

(f) The recommended assembly torque for element installation.

(g) The similarity certificate identification code.

The vessel’s design pressure (maximum working pressure) shall be at least 1 035 kPa (150 psi gauge) at

35 EC (95 EF) or as specified by the purchaser.

Each filter or separator vessel must undergo hydrostatic testing as per the relevant code Furthermore, after installation, the inlet manifold or chamber should be sealed and tested to a minimum pressure of 795 kPa (115 psi gauge).

In multi-stage systems, it is essential to blank off the outlet manifold and conduct a pressure test at a minimum of 795 kPa (115 psi gauge) or the pressure specified for the qualified multi-stage element vessel, whichever is higher.

3.2.2.12 Marking of inlets and outlets

All inlet, outlet, and sump drain connections shall be permanently marked.

To minimize vibration, all elements longer than 46 cm (18 inches) must have their free ends stabilized, regardless of the mounting assembly An effective stabilization method involves using an element spider to connect the elements, which is then secured to the vessel wall It is crucial that the spider is not an unbonded charge collector; if the stabilization method does not ensure an electrically conductive bond between the spider and the vessel, a separate bond must be established Additionally, element-locating devices should be incorporated in the spider to securely support slightly misaligned elements without inducing unnecessary strain.

Access to the vessel's elements should be ensured through a hinged or pivoted cover, with swing bolts recommended for quick interior access For maintenance purposes, the vessel's length-to-diameter ratio must adhere to specified limits, unless otherwise directed by the purchaser.

For vessels # 61 cm (24 inch) diameter: L/D # 1,75For 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,

D is the inside diameter of the vessel.

Qualification by similarity

4.1.1 Qualification of filter/separators by similarity

Numerous manufacturers offer filter/separators with comparable designs but varying flow rate ratings Qualification testing for units that are similar to those previously tested and approved may be unnecessary, as long as the criteria outlined in API/IP 1582 are satisfied.

4.1.2.1 Qualification of a filter/separator vessel consists of passing single-element tests and full-scale tests of vessels, elements and configurations similar to the vessel being qualified.

Single-element tests, as outlined in Section 4.3, are essential for every filter/coalescer and separator configuration and category If a completed single-element test meets the conditions specified in Section 4.2, there is no need to repeat these tests for each full-scale vessel evaluation.

Full-scale tests, as outlined in Section 4.4, are essential for every vessel configuration, including filter/coalescer and separator setups However, if the similarity conditions defined in API/IP 1582 are satisfied, these tests do not need to be repeated for each vessel-element configuration.

Test materials and facilities

4.2.1.1 Qualification tests shall be performed using comparable single-element test facilities, as shown in Figure 1 and full-scale test facilities as shown in Figure

The design of the solids injection facilities must align with the specifications illustrated in Figure 3, ensuring that the single-element test vessel mirrors the configuration of the full-scale vessel, whether side-by-side or end-opposed.

4.2.1.2 The single-element vessel shall be operated in the same orientation (either vertical or horizontal) as the full-scale vessel.

4.2.1.3 No tees or dead legs shall be present in the section of piping between the contaminant-injection point and the test vessel.

Test vessels utilized in single-element and full-scale tests do not need to meet all mechanical specifications outlined in section 3.2.2 For instance, the element spacing and L/D ratios specified for commercial vessels may not align with the practical needs of test vessels However, it is important to emphasize that this does not alter or lessen the similarity requirements.

4.2.1.5 The media and construction of the elements tested shall be the same as those used in the full-scale vessel.

Data sheets and drawings that outline the design of the elements being qualified must accompany the qualification test report Additionally, each full-scale test report should reference the relevant single-element test report.

Single-element testing utilizes a two-stage system consisting of a filter and separator In multi-stage vessels, additional stages are assessed exclusively through full-scale testing It is essential that the filter and separator stages in the single-element vessel are positioned relative to each other as they are in the full-scale vessel, adhering to specified criteria.

The filter and coalescer elements must be identical in model, media, and construction for both single-element and full-scale tests, with the only allowable variations being in the lengths of the elements and their end caps.

The coalescer must measure 36 ±3 cm (14 ±1 inches) in nominal length Additionally, the flow rate for each cm (inch) of the filter/coalescer should not be lower than the maximum flow rate per cm (inch) of the filter/coalescers used in the full-scale vessel.

The maximum diameter for qualified filter/coalescers is 15.5 cm (6 inches), and while the diameter may vary, it must remain consistent in both single-element and full-scale tests.

(d) The separators in single-element and full-scale testing shall be constructed of the same materials.

(e) The diameter of the separator qualified in the single-element test shall be a maximum of 15,5 cm

(6 inches) The diameter (average diameter for non-cylindrical separators) shall be the same or less than the separator(s) tested in full-scale testing.

(f) The effective length of the separator shall be no greater than 15,5 cm (6 inches).

(g) The distance between the nearest coalescer and separator elements shall not be greater than the distance between the nearest coalescer and separator elements in the full-scale vessel (δ F/C-S ).

In a single-element vessel, the minimum distances between the interior surface and the outer surfaces of the coalescer and separator elements must not exceed the distances found in the full-scale vessel, denoted as δ F/C-V and δ S-V.

(i) The orientation of the filter/coalescer and separator shall be the same as the full-scale vessel.

(i) The single-element vessel diameter (D V ) for side-by-side configurations shall be:

(ii) The single-element vessel diameter (D V ) for end-opposed configurations shall be:

For side-by-side vessels, the area of the single-element test vessel must be decreased by installing plates that align with the flow path between the filter/coalescer and separator elements The plates should be positioned so that the nearest distance from the plate to the filter/coalescer is maintained.

# 1,5 * δ F/C-F/C and the closest distance between the separator and plate shall be:

(ii) For end-opposed vessels, the single-element test vessel area ratio shall be:

A Ratio $ 0,95 * (ΣD S 2) / D FS 2 whichever is greater, where:

D V is the diameter of single-element test vessel,

D FS is the diameter of full-scale vessel,

D F/C is the diameter of filter/coalescer,

D S is the diameter of separator (average diameter for non-cylindrical separators), δ F/C-S is the spacing between full-scale vessel separator and filter/coalescer as defined inSection 4.2.1.7.g,

The testing and qualification procedure outlines specific spacing requirements for full-scale vessels The distance, denoted as \$\delta F/C-V\$, refers to the spacing between the full-scale filter/coalescer and the vessel wall, as specified in Section 4.2.1.7.h Similarly, \$\delta S-V\$ indicates the spacing between the full-scale separator and the vessel wall, also defined in Section 4.2.1.7.h Additionally, \$\delta F/C-F/C\$ represents the minimum spacing required between two filter/coalescers within the full-scale vessel, while \$\delta S-S\$ denotes the minimum spacing between two separators in the same context.

A ratio is defined as the area ratio of a filter or coalescer to a vessel In the case of end-opposed vessels, it specifically refers to the ratio of the square of the element's outside diameter to the square of the vessel's internal diameter.

4.2.1.8 The pump unit in both the single-element and full-scale testing systems shall be of the centrifugal type and shall have a minimum shaft-rotation rate of

The base fuel for all tests shall conform to ASTM D

1655 or AFQRJOS Joint Fuelling System Checklist

Specification for Aviation Fuel Jet Fuel A or A-1.

Prior to the commencement of each test series, it is essential to evaluate the test fuel using the methods outlined in Table 1, ensuring it is free of additives by adhering to the specified limits in the table.

The test fuel volume must be adequate to perform the single-element test outlined in Section 4.3 in one continuous pass, without any recycling of the test fuel during the procedure.

During testing, the test fuel must be maintained at a minimum temperature of 5 °C (40 °F) and should not exceed a maximum temperature of 32 °C (90 °F) Additionally, the temperature of the test fuel should remain within ± 6 °C (±11 °F) of the initial temperature throughout each test series.

The following contaminants shall be used for testing:

(a) Copperas Red Iron Oxide R-9998 7 or its exact equivalent.

(b) Arizona Test Dust ISO 12103-1, A1 8 (Ultra Fine) or its exact equivalent.

(c) Fresh water meeting the following:

— Solids content less than 1,0 mg/l.

— Surface tension at least 65 millinewtons per metre at 24 EC (75 EF).

(d) The test solid contaminant mixture shall consist of

10 % by weight of Copperas Red Iron Oxide R-

9998 and 90 % Arizona Test Dust ISO 12103-1, A1 (Ultra Fine).

Table 1 - Tests and limits for determining additive-free fuel

Stadis 450 < 10 pS/m < 10 pS/m ASTM D 2624 or D 4308

Corrosion inhibitor Minimal Minimal Note 1

JP8+100 < 25 mg/l N/a SPEC AID 8Q462 Residual test

Free water < 5 ppm < 5 ppm ASTM D 3240

Note 1: Fuel shall be clay treated - no accurate test for determining absence of this component.

Note 2: Test available from BetzDearbon Any more precise analytical method accepted by BetzDearbon may be substituted.

7 R-9998 can be obtained from Elementis Pigments Inc., 11 Executive Drive, Suite 1, Fairview Heights, Illinois 62208, USA.

8 Arizona Test Dust ISO 12103-1, A1 can be obtained from Powder Technology Inc., PO Box 1464, Burnsville, Minnesota

Note: The test dusts contain fine particulate.

The Arizona Test Dust ISO 12103-1, A1 contains silica The precautions prescribed by appropriate health regulations and standards must be applied when handling these materials.

Contaminants shall be added continuously and evenly, within ± 10 % of the nominal rate The test particulate shall be prepared using the procedure described in

Annex A The slurry shall be added using the apparatus shown in Figure 3.

The following additives shall be introduced to the test fuel at the time and in the quantity and manner specified by the test procedure:

(a) Additive I - Stadis 450, manufactured by Octel

Corporation and conforming to the latest product specification, shall be used at an initial concentration of 1,0 mg/l.

Note: This concentration is based on neat additive with a density of 899 kilograms per cubic metre (7,5 pounds per gallon).

(b) Additive II - DCI-4A, manufactured by Octel

Corporation and conforming to the most recent revision of MIL-PRF-25017, shall be used at an initial concentration of 15 mg/l.

(a) Additive A - SPEC AID 8Q462 Thermal Stability

The Additive, known as Aeroshell Performance Additive (APA) 101, is manufactured by BetzDearborn and supplied by Shell Aviation Ltd It is a Thermal Stability Additive that meets the latest product specifications and should be utilized at an initial concentration of 256 mg/l exclusively for Category M100 fuels.

(b) Additive B - Fuel System Icing Inhibitor, diethylene glycol monomethyl ether (Di-EGME) conforming to ASTM D-4171, Type III shall be used at an initial concentration of 0,15 % by volume.

(c) Additive C - DCI-4A, manufactured by Octel

Corporation and conforming to MIL-PRF-25017 shall be used at an initial concentration of 15 mg/l.

(d) Additive D - Stadis 450 as defined in Section 4.2.4.1(a) shall be used at an initial concentration of 2,0 mg/l.

Single-element test for filter/separators

The testing and qualification process for filter/separators involves a single pass of fuel through a single-element test unit, where different levels of contaminants are introduced upstream The analysis of effluent samples and differential pressures is conducted to ensure compliance with performance specifications The test unit must adhere to the design criteria outlined in Section 4.2, highlighting the key aspects of the single-element test.

1 Conducted in an element conditioning or single-element test unit.

2 Comprises a low-flow additive-stabilization period.

3 Fuel is Category C, or M, or M100 (with full additive package) as specified by the qualification category.

(b) Water coalescence test - Clean element (0,01 % by volume water addition)

1 Conducted in a single-element test unit.

2 Fuel flowed as a single pass.

(c) Solids holding test (19 mg/l solid addition)

(d) Water coalescence test - Solids containing element (Two water concentrations tested: 0,01 % and 3 % by volume)

Fuel preparation involves adding specific additives in a designated order to the storage tank or flow system, followed by recirculating the fuel to ensure a uniform mixture Throughout this process, the test fuel is recirculated while bypassing the test unit and any filtration or treatment systems.

The conditioning unit or single-element test vessel must utilize a test fuel from Category C, Category M, or Category M100, including the complete additive package as outlined in Section 4.2.4 Prior to the addition of any additives, the test fuel must be evaluated using the methods specified in Table 1 and confirmed to be additive-free by adhering to the test limits in Table 1 Additives should be introduced either into the storage tank or at a designated point within the recirculation system.

To achieve a well-mixed condition for each additive, it is essential to measure conductivity at 5-minute intervals for the initial additive introduced to the fuel, thereby determining the necessary duration of recirculation.

The test report should include the elapsed time from the conclusion of the additive addition until three consecutive conductivity measurements, taken at 5-minute intervals, fall within ± 20 pS/m.

To prepare fuel for conditioning elements or conducting a single-element test, the same procedure is followed Additive I should be incorporated into the test fuel as outlined in Section 4.3.2.2.1 to reach the concentration specified in Section 4.2.4.1.

The fuel must be recirculated through the unit, bypassing the single-element test vessel, for a duration of $tm Samples for assessing the conductivity of the test fuel at the test unit's inlet should be collected downstream of the storage tank.

4.3.2.3.1.3 Additive II shall be added to the fuel in a manner similar to Additive I Recirculation shall be continued at the same flow rate used for recirculating

The preparation of Category M100 fuel follows the same procedure for conditioning elements or conducting a single-element test To achieve the required concentration, Additive A must be incorporated into the test fuel as outlined in Section 4.3.2.2.1, in accordance with the specifications detailed in Section 4.2.4.2.

The fuel must be recirculated through the unit, bypassing the single-element test vessel, for a duration of $tm Samples for assessing the conductivity of the test fuel at the test unit's inlet should be collected downstream of the storage tank.

Additive B must be incorporated into the fuel to ensure effective dispersion and dissolution The recirculation process should maintain the same flow rate utilized for Additive A for a duration of $tm$ after the addition of Additive B to the system.

4.3.2.3.2.4 Additive C shall be added to the fuel in a manner similar to Additive A Recirculation shall be continued at the same flow rate used for recirculating Additive A for a period $tm.

4.3.2.3.2.5 Additive D shall be added to the fuel in a manner similar to Additive A Recirculation shall be continued at the same flow rate used for recirculating Additive A for a period $tm.

To prepare Category M fuel for conditioning elements or conducting a single-element test, follow the same procedure outlined previously Additive D must be incorporated into the test fuel as specified in Section 4.3.2.2.1 to reach the concentration detailed in Section 4.2.4.2 This additive can be introduced directly into the storage tank or at any location within the recirculation loop.

The fuel must be recirculated through the unit, bypassing the single-element test vessel, for a duration of \$tm\$ Samples for assessing the conductivity of the test fuel at the test unit's inlet should be collected downstream of the storage tank.

Additive B must be incorporated into the fuel to ensure effective dispersion and dissolution The recirculation process should maintain the same flow rate utilized for Additive D for a duration of $tm$ after the additive is introduced into the system.

4.3.2.3.3.4 Additive C shall be added to the fuel in a manner similar to Additive D Recirculation shall be continued at the same flow rate used for recirculating

In a single-element test, filter/coalescer elements can be conditioned either in a dedicated facility or within the test unit itself Multiple filter/coalescers can be simultaneously conditioned by utilizing parallel test element vessels along with a shared storage and holding tank.

In the conditioning unit, each element is placed for treatment, where fuel is transferred from the storage tank to the receiving tank at a rate of 10 litres per minute (3 gpm) for a duration of 30 minutes After this process, the filter/coalescer element can be extracted from the conditioning vessel for use in single-element tests.

Full-scale test method for filter/coalescers

4.4.1.1 The full-scale test of a two- or multi-stage vessel is conducted in the facility shown in Figure 2.

The test fuel is circulated from the storage tank through a filter/separator vessel before being returned to the storage tank, while any additional equipment, such as a clean-up filter/separator or clay treater, is bypassed during the testing process.

Compliance with the similarity criteria outlined in API/IP 1582 allows for the qualification of a filter/separator design based on successful full-scale testing of a similar design These criteria can be applied to qualify designs with lower flow rates than those tested, but not for higher flow rates, except under specific conditions This specification is applicable for flow rates ranging from 0 to 9,500 lpm (0 to 2,500 gpm) However, it is important to note that while similarity criteria typically cannot be used to qualify vessels with higher flow rates than those tested, existing vessels that were qualified under previous editions of API/IP 1581 may exceed these flow rates.

9 500 lpm (2 500 gpm) but no more than 19 000 l pm

(5 000 gpm) may be qualified by meeting similarity criteria with vessels full-scale tested at 9 500 lpm

The qualifying entity must ensure that the effluent dirt and water levels of existing vessels, which can qualify for a flow rate of 2,500 gallons per minute (gpm), are consistent with their intended use.

The fuel used in the full-scale tests shall be that specified in Section 4.2.2 The fuel shall be additive free as defined by Table 1

The test fuel volume must be at least 5% of the total fuel volume circulating through the filter/separator vessel, and it should not be recirculated more than ten times to prevent additive depletion If necessary, testing can be paused at the midpoint to clean the fuel of additives and re-additize it During an interruption, the test vessel must be isolated by closing both upstream and downstream valves, ensuring it remains undisturbed and protected from thermal shock until testing resumes Flow must be reestablished by opening the upstream valve first, followed by the downstream valve, as any reverse flow will invalidate the test Additionally, when multiple fuel tanks are utilized, the flow from each tank must not vary by more than ±10% from one another.

Additives must be introduced to the test fuel according to the specifications outlined in Section 4.2.4, ensuring they are added while the fuel circulates and bypassing any full-scale vessels or additional equipment like cleanup filters and clay treaters For a single tank, additives can be added directly to the tank or downstream in the recirculation loop In the case of multiple tanks, fuel should be drawn equally from each tank, maintaining a flow variation of no more than ± 10%, with additives added downstream of the tanks The procedure for adding additives is detailed in Section 4.3.2.3.

The full-scale test is a test of the complete design It consists of an element-conditioning step (Media

Migration), a water injection test, a solids handling test and a water injection test using solids contaminated elements.

The test elements are installed in the test vessel and the vessel is filled with Category C, M, or M100 fuel Fuel is then flowed for 30 minutes at 10 % of the rated flow.

Upon completion of the Media Migration test (Section

4.4.5.1), the fuel flow rate is increased to rated flow.

Water is injected at 0,01 % (by volume) of rated flow for 30 minutes The water sump drain shall remain closed during this period.

Every 15 minutes after the initial addition of 0.01% water, a stop/start procedure will be conducted The flow will continue after the 30-minute mark of the 0.01% water addition until all necessary samples have been collected.

At the completion of the water addition test (Section

4.4.5.2), the water is drained from the sump, then solids are injected into the system (as indicated in Figure 2) such that the concentration of solids in the test fuel is

Type S filter/coalescers require the addition of solids to the system for a duration of 45 minutes, ensuring that the pressure differential across the vessel does not exceed 105 kPa (15 psi) The addition of solids must be halted at the conclusion of the test period.

At 15-minute intervals from the beginning of the solids addition, a stop/start procedure shall be performed.

In the S-LD filter/coalescer system, solids are introduced for a duration of 45 minutes or until a differential pressure of 105 kPa (15 psi) is achieved Once this pressure differential is reached, the addition of solids is halted for the remainder of the test, while the fuel flow continues at the rated level throughout the 45-minute solids addition period.

Note: It is acceptable for the differential pressure to relax to less than 105 kPa as the test continues after solids flow is stopped.

At 15-minute intervals from the beginning of solids addition, a stop/start procedure shall be performed.

4.4.5.4 Water addition - Solids contaminated system

At the conclusion of the 45-minute interval, the addition of solids ceases while the fuel flow continues Water is then injected upstream of the pump at a rate of 0.01% (by volume) of the rated flow for 90 minutes, with the sump drain closed After this duration and the collection of necessary samples, the sump can be drained of water Subsequently, the water injection rate is increased to 3% (by volume) and maintained for 15 minutes Finally, the flow of fuel and water is halted after all required samples have been collected.

At 30-minute intervals from the beginning of the 0,01 % water addition, a stop/start procedure shall be performed No stop/start procedure is performed during

It is advisable for all filter/separator vessels to be designed for optimal performance with a 3% water challenge However, some vessels, particularly those in mobile service, may have been qualified under earlier standards where lower water contamination is expected, allowing for a reduced water injection rate of 0.5% by volume These vessels must be clearly labeled to indicate their specific applicability for this limited service.

Following the 3% water injection test, it is essential to halt the flow immediately after collecting all samples, draining the vessel, and removing the filter/coalescer A thorough inspection of the elements for structural failures is crucial, focusing on the filter element for any leaks or tears at the end caps and seams Additionally, all other areas should be examined for pinhole and larger leaks, with any detected anomalies reported as failures in the structural integrity of the element.

Discoloration of the coalescer sock does not automatically indicate a failure in structural integrity Upon noticing discoloration, the sock must be removed and inspected for signs of structural failure If a specific failure point is found, it should be documented as a structural integrity failure of the element.

4.4.5.6.1 In qualifying a multi-stage system, the testing in Sections 4.4.5.1 through 4.4.5.5 shall be conducted with the additional stage(s) installed.

Additional stages must consist of devices that meet a documented performance specification mutually agreed upon by the purchaser and manufacturer During qualification testing, the differential pressure across multi-stage water absorption devices, located downstream from the separator, should not exceed an increase of 100 kPa (15 psi).

Structural test

At least three coalescer elements of maximum length must undergo a differential pressure test to assess their structural strength, ensuring compliance with the specified requirements in the relevant section.

3.1.5 Base fuel shall be circulated through the element at the design flow rate, with R-9998 particulate added until the pressure differential is at least 520 kPa

The differential pressure of 75 psi must be maintained for a minimum of 5 minutes, ensuring that there are no ruptures in the element, seal bypassing, or leakage of iron oxide through any pinhole defects.

4.5.2 To pass the structural test, three filter/coalescer or coalescer elements, tested con-secutively, shall meet the above requirements.

Structural tests performed on the screw-base configuration of an element model meet the qualification standards for the open-ended configuration of the same model However, the structural tests for open-ended configurations do not fulfill the qualification requirements for screw-base elements.

Environmental tests

4.6.1.1 In addition to meeting the performance and mechanical specifications, the test unit shall be guaranteed by the manufacturer to meet the following requirements in accordance with recognized test procedures.

4.6.1.2 The unit shall not be adversely affected by exposure to temperatures varying from –54EC to +71 EC (–65 EF to +160 EF).

The media elements, gaskets, sealing materials, and internal coatings must remain stable and undeterred when exposed to fresh water, salt water, or aviation fuels, and they should not encourage fungal growth.

Compatibility tests require soaking test elements, including separators, in specified test fluids as outlined in Table 2 The elements used must match the model being qualified, and if a model has previously passed compatibility testing, retesting is unnecessary for future vessel qualifications The smallest available element length, currently 36 cm (14 inches) or longer, may be utilized, provided it comes from the same lot as the test element Additionally, the diameter of the elements must be the largest size produced for that model, and the soaking solution volume should be five times the volume of the test element based on its outer dimensions.

4.6.2.2 To avoid error, the containers used for testing shall have the following characteristics:

(a) The containers shall be identical for all tests and each shall each have a sealable non-contaminating cap.

(b) Containers shall be sized to permit the specimen to be totally immersed in the test solution.

Containers must be made of materials such as aluminum, stainless steel, or epoxy-lined metal to ensure they do not interfere with test results Additionally, since fuel is sensitive to light, it is essential to store these containers in dark enclosures when they contain fuel.

(d) Containers shall be thoroughly rinsed with the base fuel before use.

The test fluids outlined in Table 2 include base (unadditized) fuel for Tests 1 and 2, as detailed in Section 4.2.2, along with specified additives from Section 4.2.4 For Test 4, the required test fluid consists of 30 volumes of toluene (minimum 98% purity) and 70 volumes of iso-octane (minimum 98% purity).

3 shall be diethylene glycol monomethyl ether

(Di-EGME), (ASTM D 4171, Type III).

4.6.2.4.1 Reference samples: One litre (1 quart) reference samples of test fluids 1, 2, and 4 shall be taken at the beginning of each soak period (before contact with elements).

4.6.2.4.2 Soak periods: Elements shall be soaked in appropriate test fluids for 336 hours in all tests In Tests

1, 2, and 4, the elements shall be drained for 4 hours and subjected to a second 336-hour soak period using freshly prepared test fluid.

4.6.2.4.3 Required samples: A sample of each test fluid shall be taken at the end of each 336-hour element- contact period

4.6.2.4.4 Analyses and report: Reference and test samples shall be tested by the analyses shown in Table

2 and reported in the form shown in Table 3.

4.6.2.5 Further testing, followed by a field service evaluation, may be required to identify a problem component within an element if one or more of the following results is obtained:

(a) The water separometer index modified (MSEP) result in Test 1 drops below 85.

(b) The water reaction results have an interface rating above 1b in Tests 1 and 2 and/or a separation rating above 2 in any test.

(c) The colour in Tests 1, 2, and 4 decreases by more than 4 units when compared with that of the base fuel measured at the same time.

(d) Further testing and subsequent field service evaluation is also required if requested by the purchaser.

4.6.2.6 Test samples shall meet the following criteria for existent gum, as determined by steam jet in accordance with ASTM D 381:

(a) The existent gum level shall increase by less than

8 mg/100 ml in any test.

If the amount of existing gum rises by over 3 mg/100 ml after the initial soaking period, the increase observed during the second soaking must not exceed 50% of the increase recorded in the first soaking period.

Elements from Tests 1, 2, and 4 that fulfill the specified criteria will undergo the structural test detailed in Section 4.5 to verify compliance with the standards in Section 3.1.5 However, separators do not require structural tests due to the absence of high differential pressures; they only need to satisfy the compatibility criteria outlined in Table 2.

Test sampling

The test sampling schedules are uniform across all categories and types of filter/separator systems For media migration of single elements and single-element tests, the sampling schedule is detailed in Table 4, while the full-scale tests are outlined in Table 5 All test samples must adhere to the specifications provided in Section 3.1.

(a) For media migration - a minimum of 11 litres (3 gallons).

(b) For weight of solids (non continuous) - a minimum of 4 litres (1 gallon).

(c) For weight of solids (continuous) - a maximum of

(d) For free water content - sufficient sample size to satisfy the test apparatus.

(e) For fuel conductivity - sufficient to cover the electrodes of the conductivity cell.

Note: Conductivity samples shall be taken only in metal containers.

Analysis procedures shall conform to the latest revisions of the following specifications:

(a) For MSEP - ASTM D 3948 (microseparometer). (b) For media migration - ASTM D 2276.

(d) For free water content - ASTM D 3240 (Aqua- glo).

Note: Measurements of fuel conductivity shall be made within 5 minutes after the sample is drawn.

An upstream-facing sampling probe shall be provided within 10 pipe diameters of the test unit’s outlet or inlet

To ensure accurate measurements, the probe must be positioned at least five diameters upstream from any bends or obstructions in the pipe Additionally, the design of the sample pipe and the upstream piping should prevent the settling of particles or water, maintaining a consistent flow pattern.

Test data

The test data will be displayed in tables, specifically Tables 6 and 7 Furthermore, comprehensive test data for the test fuel must be supplied in accordance with the relevant ASTM or Joint Inspection Group specifications.

Table 2 - Compatibility tests for filter/coalescer elements

Test Test Fluid Test Specimen Needed in

1 Jet A or Jet A-1 Yes ABCDE

2 Jet A or Jet A-1 with 12 mg/l of HiTEC E-580 and 3 mg/l of Stadis 450

3 100 % fuel system icing inhibitor (Di-EGME) Yes D

4 30 % toluene/70 % iso-octane Yes BDE a) A = MSEP (ASTM D 3948); B = Existent gum (ASTM D 381 (Steam jet)); C = Water reaction (ASTM D 1094);

D = Detailed inspection and description of all component parts; E = Color (ASTM D 156).

Table 3 - Report form for compatibility results

Test Test Fluid Test Hours Comments

12 mg/l of HiTEC E-580 and 3 mg/l of Stadis 450

WATER REACTION TEST (INITIAL SOAK ONLY)

Note: To report separator results, substitute "separator" for "element" above.

3 100 % Fuel system Inhibitor(Di-EGME)

Note: To report separator results, substitute "separator" for "element" above.

Table 4 - Test sampling schedule and procedures for single-element tests

Samples Are Taken Sample Size

Storage tank Conditioning unit outlet

Special container In-line sampler Water removal 4.3.2.5 At 5, 10, 20 and 30 minutes c)

As required by ASTM practice

Free water content 4 Test unit outlet Aqua-glo

Solids handling 4.3.2.6 Every 15 minutes before and after stop-start

4/1 Solids 10 Test unit outlet In-line sampler

Aqua-glo a) Minimum. b) One sample for each element conditioned - sample taken from point before common manifold when multi-elements conditioned. c) After stop/start - test continued until sample obtained.

Table 5 - Test sampling schedule and procedures for full-scale tests

Samples Are Taken Sample Size

Storage tank Outlet of filter/separator vessel

Special container In-line sampler

Water removal 4.4.5.2 At 5, 10, 20 and 30 minutes b)

Free water content 4 Outlet of filter/separator vessel

Solids handling 4.4.5.3 Every 15 minutes before and after stop/start

4/1 Solids 6 Outlet of filter/separator vessel

Outlet of filter/separator vessel

Table 6 - Data sheet for single-element tests

Test Specification: API/IP 1581 5 th Edition Date:

Vessel: Filter/Coalescer: Separator: Type: G-S G-S-LD

Additive Addition Model Number Model Number

Element Conditioning: G-In-Situ G-External

Copyright American Petroleum Institute Reproduced by IHS under license with API Not for Resale No reproduction or networking permitted without license from IHS

Table 6 - Data sheet for single-element tests continued (Note For Type S filters only)

75 s/s a) s/s: sample taken immediately after conclusion of stop/start

Table 6 - Data sheet for single-element tests continued (Note For Type S-LD filters only)

Sol id s H ol di n g Tes t (Continue until reaching 115 kPa/22, 5 psi)

Table 6 - Data sheet for single-element tests continued.

Table 7 - Data sheet for full-scale tests Test Specification: API/IP 1581 5th Edition Single-Element Test Report Referenced: Date:

Vessel: Filter/Coalescer: Separator: Type: G-S G-S-LD

Additive Addition Model Number Model Number

Table 7 Data sheet for full-scale tests continued.

Solids Holding Test (For Type S Only)

45 s/s a) FC: filter/coalescer. b) s/s: sample taken immediately after conclusion of stop/start.

Table 7 Data sheet for full-scale tests continued (Note: For Type S-LD filters only)

Solids Holding Test (Stop solids addition @ 105 kPa/15 psi

% 45 s/s a) s/s: sample taken immediately after conclusion of stop/start.

Table 7 Data sheet for full-scale tests (continued).

Flow rate >1,0 m/sec (3,3 ft/sec)

Fuel Tank Single Pass Capacity

1 All equipment & construction must meet applicable codes.

2 Cleanup equipment recommended Actual equipment & configuration can depend on local conditions.

3 Storage shown is minimum acceptable.

4 All sample probes installed as per ASTM D 4703.

5 Slurry system details in Figure 3.

6 Provision must be made to verify calibration of:

Slurry Injection System Defined in Figure 3

1 All equipment & construction must meet applicable codes.

2 Cleanup equipment recommended Actual equipment & configuration can depend on local conditions.

3 Storage shown is minimum acceptable.

4 All sample probes installed as per ASTM D 4703.

5 Slurry system detail in Figure 3.

6 Provision must be made to verify calibration of:

Flowmeters Differential pressure gauges Slurry flow rate

Figure 2 - Full-Scale Test Facility

(Positive displacement Pump Variable Speed)

Pump (Flow greater or equal to

20 % of Tank Initial Volume per Minute)

Velocity greater or equal to 1,0 m/sec (1,7 ft/sec)

Pump (Positive displacement Variable Speed)

Velocity greater or equal to 1,0 m/sec (1,7 ft/sec)

Injection point downstream of centrifugal pump not less than 10 pipe diameters from test vessel

1 Slurry Volume concentration determined by flow rate (maximum 15 g/litre).

2 Pump is variable speed positive displacement.

3 For Alternative 2, displacement pump sized to recirculation rate at >20 % of initial tank volume/min at required injection rate.

4 For Alternative 2, injection rate must be measured by

Conditioning can be done as above or in place API/IP 1581 Flowsheets

Figure 4- Element Conditioning REVISION DATE:

The solids shall be dry (by heating at 100EC for 3 hours) and free from large agglomerates greater than

The test solids shall be composed of 90 % Arizona Test

Dust ISO 12103-1, A1 and 10 % Copperas Red Iron

Oxide Thus, for every 1 litre/minute flow rate of the coalescer in the single-element test (which requires

1,43 g solids per litre/minute flow), add to the slurry system:

— 1,29 g of Arizona Test Dust ISO 12103-1, A1,

— 0,14 g of Copperas Red Iron Oxide.

To ensure accurate results during the solids addition test, it is essential to add extra solids in the same ratio to compensate for any residual slurry volume left in the tank.

The solids can be added to the slurry tank in a number of ways:

— Add measured amounts of solids directly to the tank containing the correct amount of fully additized fuel.

— Add a concentrated slurry of the required solids directly to the tank.

— Add a concentrated slurry of the solids into a point in the recirculation loop of the slurry equipment (shown in Figure 3).

At the completion of adding the solids, the tank will be circulated for at least 20 minutes before injecting into the main piping as part of the solids addition tests.

The solids slurry shall be metered into the test fuel flow system at the appropriate rate to provide a solids concentration of 19 mg/l (72 mg/gallon) in the test fuel.

Tiêu đề	Specifications and Qualification Procedures for Aviation Jet Fuel Filter/Separators API/IP Specification 1581
Tác giả	American Petroleum Institute, The Institute of Petroleum
Trường học	The Institute of Petroleum
Chuyên ngành	Petroleum Engineering
Thể loại	Specification
Năm xuất bản	2002
Thành phố	London

Định dạng
Số trang	50
Dung lượng	481,02 KB