BS ISO 19631:2015 pdf download – Aerospace series — Tube fittings for fluid systems, 5 080 psi (35 000 kPa) — Qualification specification
1 Scope
This International Standard specifies performance and quality requirements for the qualification andmanufacture of standard tube fittings to ensure reliable performance in aircraft hydraulic 5 080 psi(35 000 kPa) systems.
This International Standard specifies baseline criteria for the design and manufacture of systemfittings that are qualification tested on engines.
This International Standard covers fittings from size -O4 to -20 used for the following:-separable/permanent pipe end fittings;
– permanent connection fittings;
-separable connection fittings.
This International Standard covers fittings of the temperature types and pressure classes specified inISO 6771.
2Normative references
The following documents, in whole or in part, are normatively referenced in this document and areindispensable for its application. For dated references, only the edition cited applies.For undatedreferences, the latest edition of the referenced document (including any amendments] applies.
ISO 2685,Aircraft – Environmental test procedure for airborne equipment — Resistance to fire indesignated fire zones
ISo 6772,Aerospace —Fluid systems — Impulse testing of hydraulic hose, tubing and fitting assemblies
ISO 6773,Aerospace — Fluid systems — Thermal shock testing of piping and fittings
ISo 7137,Aircraft —Environmental conditions and test procedures for airborne equipment
ISO 7257,Aircraft — Hydraulic tubing joints and fittings — Rotary flexure test
ISO 10583:1993,Aerospace fluid systems —Test methods for tube/fitting assembliesEUROCAE ED-14E/RTCADO-160E,Section 22, Lightning Induced transient Susceptibility
Fittings claiming conformity with this International Standard shall be representative of products,which have successfully met the requirements and have passed the tests in this International Standard.3.1.1 Manufacturer qualification
Manufacturer approval shall be granted by purchaser qualification procedure.
3.3.2Temperature Ambient Air: -54 C to +135 °C3.2.2.2 Hydraulic Fluid:-54 °C to +135°C3.4Design and manufacture
3.4.1 Fluid passages
On fittings where the fluid passage is drilled from each end, the offset between the drilled holes at themeeting point shall not exceed 0,25 mm(0.10 in). It shall be possible to pass through the fitting passagea ball whose diameter is 0,37 mm (0.015 in) less than the minimum diameter specified for the passage.Angular misalignment shall not exceed 1° for straight fittings and 2° for shaped fittings.
The tubing/fitting assembly shall be capable of meeting the performance requirements specified in3.5.1 to 3.5.21.
3.5.1Specimen preparation
Test specimens shall be assembled as specified in Table 11.Sleeve installations on the tube end shall bein accordance with user instructions.
The fitting shall be assembled to tightening torques given by purchaser procurement specification, usingthe maximum installing torque for half of the test specimens and the minimum torque for the other half. Lubricants
Hydraulic system fittings shall be assembled using system fluid as lubricant on the union threadand sleeve shoulder only. No lubricant on the sealing surfaces(especially during pneumatic leakagetesting) is allowed. inspection
Test assemblies shall consist of the parts specified in 3.5.1. Tests shall be conducted in accordance withTable 11 and with ISO 10583 for each size and material for which qualification is required.
Fittings claiming conformity with this specification shall be considered qualified if they aremanufactured to the same dimensions, using the same materials and processes as products that havesuccessfully met the requirements and have passed the tests in this specification.
3.5.2 Proof pressure
When testing in accordance with ISO 10583:1993,5.1, the test assembly shall withstand the proofpressure specified in Table 3 without leakage, evidence of permanent deformation, or other malfunctionthat might affect the ability to disconnect or connect the joint in the normal manner (to the interfacepoint by hand and then using the specified range of torque values).
Specimens to be proof tested are given in Table 11.
3.5.3 Gaseous pressure
When tested in accordance with ISO 10583:1993,5.2, assemblies shall pass the gaseous pressure test tothe DOP specified in Table 3 without leakage or other failure.
Specimens to be gaseous pressure tested are given in Table Hydraulic impulse resistance
Six specimens shall be tested with the following distribution:- 2 non aged specimens;
一2 fuel aged specimens as per 3.5.16;
– 2 hydraulic fluid aged specimens as per 3.5.17.
When tested in accordance with lSO 6772 and lSo 10583:1993,5.3, the test assembly shallwithstand, without leakage, 300 000 impulse pressure cycles with pressure peaks specified andtemperatures in Table 4.