SAE-AS-1960-1986-R2007.pdf
AEROSPACE STANDARD AS1960 Issued1986-06 Reaffirmed2007-08 Coupling Assembly, V-Band, Sheet Metal Flange, Pneumatic Tube 1.SCOPE: 1.1This specification defines the requirements for a grooved clamp coupling and flanges suitable for joining intermediate pressure and temperature ducting in aircraft air systems. The rigid coupling joint assembly, hereafter referred to as “the joint“, shall operate within the temperature range of -65 °F to +800 °F. 2.APPLICABLE DOCUMENTS: The following documents of the issues in effect on the date of invitation for bid or request for proposal shall form a part of this specification to the extent specified herein. 2.1Specifications: 2.1.1Military: MIL-W-6858Welding, Resistance, Aluminum Magnesium, Nonhardening Steels or Alloys, Nickel Alloy, Heat Resisting Alloys, and Titanium Alloy, Spot and Seam MIL-W-8611Welding, Metal Arc and Gas, Steels and Corrosion and Heat Resistant Alloys; Process for MIL-S-8879Screw Threads, Controlled Radius Root with Increased Minor Diameter: General Specification for RATIONALE This document has been reaffirmed to comply with the SAE 5-Year Review policy. SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright © 2007 SAE International All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org Copyright SAE International Provided by IHS under license with SAELicensee=Defense Supply Ctr/5913977001 Not for Resale, 12/04/2007 21:16:29 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AS1960 - 2 - 2.2Standards: 2.2.1Military: DOD-STD-100Engineering Drawing Practices MIL-STD-129Marking for Shipment and Storage MIL-STD-130Identification Marking of U.S. Military Property MIL-STD-810Military Standard Environmental Test Methods MIL-STD-831Test Reports, Preparation of 3.REQUIREMENTS: 3.1Qualification: The joint furnished under this specification shall be a product identical to specimens which have successfully passed the tests specified in Section 4 of this specification. 3.2Materials: The joint component materials shall be uniform in quality, free from defects, suitable for service, consistent with good manufacturing practices, and in conformance with the applicable specifications and requirements stated herein. Specific materials used in the joint components shall be specified on the applicable AS standard drawing. 3.2.1Duct Material: Duct materials will be stainless steel and titanium. The coupling joint shall meet the requirements herein when assembled on stainless or titanium flanges. 3.2.2Equipment Flanges: Equipment flange materials may be stainless steel, titanium or aluminum. The flange may be solid, machined, forged or cast shape. For an aluminum flange joint, the maximum temperature is +260 °F. 3.3Design and Construction: The joint consisting of coupling and flanges listed in Table 1 shall fulfill all design and performance requirements of this specification. 3.3.1Coupling: The material of the coupling shall be corrosion resistant alloy as specified on the applicable AS drawing noted in Table 1. 3.3.1.1Coupling Retainer Strength: The coupling shall maintain joint integrity at operating pressure in the event of coupling retainer failure. The coupling shall be so designed that 3/4 of the coupling retainer circumference shall be sufficient to hold the joint and leakage shall not exceed 0.03 SCFM per inch of diameter at operating pressure of Table 2 at 800 °F. Copyright SAE International Provided by IHS under license with SAELicensee=Defense Supply Ctr/5913977001 Not for Resale, 12/04/2007 21:16:29 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AS1960 - 3 - 3.3.2Flanges: The material of the flanges shall be corrosion resistant alloy as specified on the applicable AS drawing shown in Table 1. TABLE 1 - Joint Component Control Numbers 3.3.3Welding: Resistance or fusion welding shall be in accordance with MIL-W-6858 or MIL-W-8611. 3.3.4Bolt: Bolt material shall be as specified on the applicable AS drawing, with an ultimate tensile strength of 160,000 psi. 3.3.4.1Bolt Threads: Bolt threads shall conform to MIL-S-8879, and may be lubricated using an anti-sieze high temperature lube. 3.3.5Nut: The nut shall be a self locking type with a running torque of 1.8 to 30 inch lbs. The material shall be as specified on the applicable coupling drawing. The nut shall have a minimum life of ten (10) complete full on-off cycles without damage to the bolt or nut or threads when installed within 120 rpm on the bolt. 3.3.6Safety Latch: The safety latch, when specified shall be a permanent part of the coupling and shall engage and maintain joint integrity in the event of primary bolt failure. Joint leakage shall not be in excess of 0.03 (SCFM) per inch of diameter at operating pressure of Table 2 while being supported only by the safety latch (failed bolt case). The safety latch shall not require any tools for its operation or release. The safety latch shall be automatically positioned when the clamp is installed, and must be designed so that failure of the primary bolt is clearly evident on visual inspection. 3.3.7Duct Installation: The coupling joint shall be so designed as to permit removal of a single duct section without moving mating ducting axially. Each joint must be self aligning during assembly. The self aligned joint may have a total of .06 transverse mismatch and must meet the requirements herein. Copyright SAE International Provided by IHS under license with SAELicensee=Defense Supply Ctr/5913977001 Not for Resale, 12/04/2007 21:16:29 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AS1960 - 4 - TABLE 2 - Minimum Rated Limit Load Capability Copyright SAE International Provided by IHS under license with SAELicensee=Defense Supply Ctr/5913977001 Not for Resale, 12/04/2007 21:16:29 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AS1960 - 5 - 3.4Temperature: The joints shall meet the requirements of this specification under any combination of ambient/fluid temperature exposure within the range of -65 °F to +800 °F. 3.5Performance: The values specified herein shall define the requirements for satisfactory performance and shall apply to performance under the conditions as specified in 3.4. 3.5.1Static Leakage: The joint, consisting of the coupling and flanges noted in 3.3. shall show no evidence of leakage in excess of 0.01 SCFM (.000765 lbs. dry air per minute) per inch of diameter when subjected to the requirements specified herein. 3.5.2Rated Limit and Ultimate Load: The coupling joint shall be capable of carrying the total limit load “N“ as a minimum, see Figure 1, specified in Table 2 without deformation or exceeding the leakage requirement of 3.5.1 with respect to the following relationship: Where: Np = Load - Pounds per inch of circumference due to pressure. Nb = Load - Pounds per inch of circumference due to bending. Na = Load - Pounds per inch of circumference due to axial loading. 3.5.2.1Pressure: The rated load per inch of circumference due to pressure shall be determined from the following relationship: Where: NP= Load - pounds per inch of circumference due to pressure P= Pressure in psi D= Flange outside diameter in inches N = Np + Nb + Na N PD P = 4 Copyright SAE International Provided by IHS under license with SAELicensee=Defense Supply Ctr/5913977001 Not for Resale, 12/04/2007 21:16:29 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AS1960 - 6 - 3.5.2.2Bending: The rated load per inch of circumference due to bending shall be determined from the following relationship: Where: Nb= Load pounds per inch of circumference due to bending (limit) M = Bending moment in inch pounds. D= Flange outside diameter in inches. 3.5.2.3Axial Load: The rated load per inch of circumference due to axial loading shall be determined from the following relationship: Where: Na= is in pounds per inch due to axial load E= Axial tension load in pounds. D= Flange outside diameter in inches. 3.5.2.4Rated Load: Limit = 2.0 Times operating load (proof load) Ultimate = 3 Times operating load (burst load) 3.5.1 may be exceeded. Deformation may occur but the joint shall remain permanently connected. 3.5.3Proof Pressure: The joint shall show no evidence of deformation or leakage in excess of 3.5.1, when subjected to the proof pressure of Table 2. 3.5.4Burst Pressure: The joint shall not rupture and shall remain intact when subjected to the burst pressure of Table 2 for 2 minutes. Deformation shall be allowed. 3.5.5Torsional Moment: The joint shall not rotate or deform when subjected to the torsional moment specified in Table 3 at operating pressure of Table 2 at 70 °F. The joint may rotate to 90° but shall not leak in excess of the rate specified in 3.5.1. N M D b = 4 2 N E D a = Copyright SAE International Provided by IHS under license with SAELicensee=Defense Supply Ctr/5913977001 Not for Resale, 12/04/2007 21:16:29 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AS1960 - 7 - TABLE 3 - Torsional Load 3.5.6Vibration: The joint, when pressurized to operating pressure of Table 2 at 70 °F shall show no evidence of leakage in excess of that specified in 3.5.1 during or after exposure to vibration levels per applicable portions of MIL-STD-810, Procedure I and paragraph 4.5.4 of this specification. There shall be no cracking, or chipping of parts. 3.5.7Pressure Cycling: The joint shall not permanently deform, or show evidence of fatigue failure after being subjected to 144,000 operating pressure impulse cycles per Table 2 and 4.5.5, at 800 °F. Leakage shall not exceed that specified in 3.5.1. 3.5.8Combined Load directly opposite the contacting side, a gap shall be measured between the flanges equivalent to 0.015 inch displacement. After the proper gap has been established one of the holding fixtures may be loosened to permit axial movement yet maintaining the displacement. The coupling shall then be installed on the flanges and tightened to the specified torque. The joint shall not be tapped or hammered to aid in seating the coupling. After assembly, the test joint shall be pressurized to proof pressure specified in Table 2 at elevated temperature. A leakage test shall be conducted at the elevated temperature and pressure and recorded. 4.5.8Thermal Shock: The test assembly shall meet the requirements of 3.5.10 when subjected to 10 cycles of thermal shock. The test joint shall be rigidly supported at one end with the other end unrestrained. The test assembly shall have attached to it, associated equipment necessary to measure leakage through the test assembly, and maintain the desired internal pressure and temperature (see Figure 4). The assembly shall then be placed in a chamber. The ambient air temperature in the test chamber shall be -65 °F. The internal pressure shall be normal operating pressure of Table 2. The internal temperature shall be -65 °F as a result of cold soaking at least one hour. At the end of one hour a joint leakage test shall be made. After completion of the leakage test, the test assembly internal temperature shall be raised as quickly as possible to 800 °F and stabilized while adjusting the internal pressure as specified in Table 2. A leakage test shall be conducted at the elevated temperature when the assembly temperature has stabilized. Copyright SAE International Provided by IHS under license with SAELicensee=Defense Supply Ctr/5913977001 Not for Resale, 12/04/2007 21:16:29 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AS1960 - 15 - 4.5.9Compressive Load: The fully mated test assembly shall be subjected to 10 compressive load cycles specified in Table 5. The load shall be at a rate not to exceed 100 pounds per second on the unpressurized test assembly at 800 °F. The compressive load shall be applied and held for one minute. At the conclusion, the load shall be relaxed and the assembly shall be pressurized to a operating pressure of Table 2 at 800 °F, a leakage test shall be made at that pressure. This shall constitute one cycle. The test assembly shall meet the requirements of 3.5.11 during and after this test. 4.5.10 Retainer Strength Test: The retainer shall be cut along one leg for a distance of 1/4 circumference or one complete segment may be cut on coupling containing four (4) equal segments. The coupling shall then be installed and subjected to normal operating pressure at 70 °F. The joint shall meet the requirements of 3.3.1.1. 4.5.11 Safety Latch Cycling: The coupling joint shall be engaged using the T-Bolt or a device simulating the T-Bolt. The coupling shall be rigged to the full torque condition. The joint shall then be pressurized at normal operating pressure of the Table 2 at 70 °F. While in the fully torqued condition, the bolt shall be severed or a latch action duplicating bolt severing. This shall constitute one cycle. The procedure shall be repeated for a total of 20 cycles. The joint shall meet the requirements of 3.3.6. 4.5.12 Nut Life: The coupling shall be installed on a mandrel and torqued to the specified torque on the coupling as standard. The nut shall then be cycled off and on 10 times. Any interference, binding, galling, misalignment, permanent set, dimensional discrepancies or excessive nut running torque, shall be noted in the test report. 4.5.13 Disassembly and Inspection: Upon completion of the tests, the coupling shall be disassembled and each part and each tubing or fitting end carefully examined for any permanent deformation. Any permament deformation of any part not previously specified shall be so noted in the test report. 5.PREPARATION FOR DELIVERY: 5.1Packaging: Packaging shall be as necessary to assure delivery of components in a clean and undamage
