API IP Spec 1581:2002 pdf download
API IP Spec 1581:2002 pdf download.SPECIFICATIONS AND QUALIFICATION PROCEDURES FOR AVIATION JET FUEL FILTER/SEPARATORS.
3.1.5 Structural strength of elements
The filter/coalescer elements, coalescer elements, and the element sealing device shall be capable of withstanding a differential pressure of 520 kPa (75 psi) without rupture, by-passing of seals, or the emergence of pinhole leaks.
3.1.6 Structural integrity
Filter/coalescer and coalescer elements shall meet single-clement and full-scale performance tests without showing indications of media or structural deterioration such as leaks or tears. Note that coalescer sock discoloration in the absence of supporting observation is insufficient to prove failure of structural integrity (see 4.3.2.8 and 4.4.5.5).
3.2 MECHANICAL SPECIFICATIONS
3.2.1 General
The acceptability of a design ultimately depends on satisfactory functioning of the vessel and components during the performance tests described in Section 4.
3.2.2 Vessel design and construction
3.2.2.1 Design codes
Filter/separator vessels shall be designed and constructed in accordance with the most recent edition and revision of Section VIII of the ASME Boiler and pressure vessel code or with equivalent codes applicable in the region of intended use.
3.2.2.2 Materials of construction
3.2.2.2.1 All metal parts that contact fuel, with the exception of sensing lines, shall contain no zinc, copper, or cadmium or their alloys. Vessels shall be of stainless steel, anodized aluminium, carbon steel, or aluminium chemically converted in accordance with the most recent edition and revision of MIL-C-5541. Carbon steel vessels shall be internally coated with a white or light-coloured surface coating which shall not deteriorate upon exposure to fresh or salt water or aviation fuels, nor shall the coating affect fuel quality. Epoxy coatings conforming to the most recent edition and revision of MIL-PRF-4556 or an equivalent specification and other purchaser-approved coatings that have demonstrated equivalent or superior performance (to these epoxy coatings) are suitable.
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/separator shall be provided with a tap for a pressure relief valve to relieve pressure from thermal expansion of the fuel. A connection for an air eliminator shall be provided at the highest point in the vessel.
3.2.2.4 Sample taps
Sample taps shall be provided to permit the taking of influent and effluent fuel samples during fuel flow. Each sample tap shall be large enough to accept, at least, a 1/4-inch National Pipe Thread probe assembly or an assembly of similar size, as applicable in the region of intcnded use.
3.2.2.5 Pressure taps
Pressure taps shall be provided to connect the appropriate pressure gauges or sensors to the filter/separator. The gauges or sensors shall permit reading the inlet pressure to the vessel and the outlet or total differential pressure. For multi-stage systems, pressure taps to measure the pressure drops across the filter/coalescer and across the separator and additional stage(s) shall be provided.
3.2.2.6 Cleanout/inspection connection
Access shall be provided to permit inspection and cleanout of all inaccessible chambers of the vessel, such as sumps and locations under or behind deck plates and manifolds. Acceptable provision for access shall be provided by the use of a 10 cm (4 inch) flanged cleanout connection when permitted by the design and construction code or an alternate scheme providing equivalent accessibility. Access schemes requiring the removal of the vessel’s inlet or outlet piping are unacceptable. Access schemes should be engineered to minimize the volume of deadlegs.
3.2.2.7 Drain and sample connections
Water drains, sample drains, or both shall be provided at the low points of the inlet and outlet compartments and of the deck plate. Welded half-couplings 19 mm (0,75 inch) in diameter, furnished with pipe plugs, will satisfy this requirement. To ensure positive drainage, drains shall run from the bottom of the sump collection area.
