1、_ 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 there
2、from, 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 2009 SAE International All rights reserved. No part of this publication m
3、ay 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: +1 724-776-4970 (outside U
4、SA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/ARP4378B AEROSPACE RECOMMENDED PRACTICE ARP4378 REV. B Issued 1997-10 Reaffirmed 2002-07 Revi
5、sed 2009-08 Superseding ARP4378A Aerospace - Accumulator, Hydraulic, Welded Bellows, Factory Precharged RATIONALE ARP4378 Rev A incorporated many changes to technical and test requirements. Rev B was introduced to correct an error in Table 1 that occurred in the update to Rev A. TABLE OF CONTENTS 1.
6、 SCOPE 4 1.1 Purpose . 4 1.2 Field of Application 4 2. REFERENCES 4 2.1 Applicable Documents 4 2.1.1 SAE Publications . 4 2.1.2 U.S. Government Publications 5 2.1.3 Code of Federal Regulations (CFR) . 5 2.2 Related Publications . 5 2.2.1 SAE Publications . 5 2.2.2 FAR Publications . 5 2.3 Definition
7、s . 5 3. TECHNICAL REQUIREMENTS 7 3.1 General . 7 3.2 Functional Requirements 7 3.2.1 Dynamic Performance Requirements . 7 3.2.2 Precharge Pressure 8 3.2.3 Swept (expelled) Oil Volume . 8 3.2.4 Maximum Swept Oil Volume . 8 3.2.5 Volumetric Efficiency . 8 3.2.6 Separator Friction 8 3.2.7 Leakage Requ
8、irements . 8 3.2.8 Operating Temperature . 8 3.3 Pressure Monitoring 9 3.4 Construction 9 3.4.1 Fluid Port and Gas Charging Point . 9 3.4.2 Fragmentation . 9 3.4.3 Materials 9 3.4.4 Corrosion Resistance 9 3.4.5 Electro-conductive Bonding 10 3.4.6 Precharge Gas 10 3.4.7 Hydraulic Fluid 10 3.5 Install
9、ation Requirements . 10 Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE ARP4378B Page 2 of 25 3.5.1 Mounting Requirements 10 3.5.2 Marking . 10 3.6 Strength . 11 3.6.1 Separator 11 3.6.2 Proof Pr
10、essure 11 3.6.3 Burst Pressure 12 3.6.4 Pressure Impulse 12 3.6.5 Vibration 12 3.6.6 Maximum Wrenching Torque 12 3.7 Weight . 12 3.8 Environmental Requirements 13 3.9 Operational and Safety Requirements 13 3.9.1 Storage 13 3.9.2 Reliability . 13 3.9.3 Endurance Cycling 13 3.9.4 Safety 14 4. QUALITY
11、ASSURANCE PROVISIONS 14 4.1 Responsibility for Inspection . 14 4.2 Physical Defect Inspection 14 4.3 Classification of Tests . 14 4.4 Test Stand Requirements . 15 4.4.1 Test Medium . 15 4.5 First Article Inspection . 15 4.5.1 First Article Samples . 15 4.5.2 First Article Inspection Report . 15 4.5.
12、3 Rejection . 15 5. ACCEPTANCE TESTS . 17 5.1 Visual and Dimensional Examination . 17 5.2 Test Program 17 5.2.1 General . 17 5.2.2 Proof Pressure 18 5.2.3 Precharge Pressure Verification . 18 5.2.4 Separator Friction 18 5.2.5 Volumetric Efficiency . 19 5.2.6 Helium Leak Test 19 5.2.7 Electro-Conduct
13、ive Bonding . 19 5.3 Preparation for Shipment 19 5.4 Storage and Packing . 19 6. QUALIFICATION TESTS 19 6.1 General . 19 6.2 Fluid Immersion Test 20 6.2.1 Fluid Immersion . 20 6.2.2 Electrical Components 20 6.3 Function Tests . 20 6.3.1 Gas Volume Verification . 20 6.3.2 Volumetric Efficiency . 20 6
14、.3.3 Endurance Cycling 21 6.3.4 Additional Tests . 21 6.4 Electrical Tests 21 6.4.1 Magnetic Effect . 21 6.4.2 Radio Frequency Susceptibility (Radiated and Conducted) Test . 21 6.4.3 Emission of Radio Frequency Energy Test 21 6.5 Environmental Tests . 21 6.5.1 Extreme Temperature Functioning Tests .
15、 21 6.5.2 Humidity 22 6.5.3 Fluids Susceptibility. 22 Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE ARP4378B Page 3 of 25 6.5.4 Fungus 22 6.5.5 Salt Spray 22 6.5.6 Fire Resistance . 22 6.6 Stru
16、ctural Tests . 23 6.6.1 Proof Pressure Test 23 6.6.2 Fatigue (Pressure Impulse) Test 23 6.6.3 Vibration Tests 23 6.6.4 Handling Loads Test . 24 6.6.5 Wrench Load Test . 24 6.7 Destructive Tests 24 6.7.1 Vessel Burst Pressure 24 6.7.2 Fragmentation . 24 6.7.3 Additional Tests . 25 6.8 Post Qualificat
17、ion Tests 25 6.8.1 Acceptance Tests . 25 6.8.2 Inspection 25 7. NOTES 25 TABLE 1 IMPULSE CYCLING . 12 TABLE 2 ENDURANCE CYCLING 13 TABLE 3 TEST PROGRAM . 16 Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IH
18、S-,-,-SAE ARP4378B Page 4 of 25 1. SCOPE This Aerospace Recommended Practice (ARP) provides design and test requirements for factory precharged, welded bellows hydraulic accumulators. 1.1 Purpose The requirements contained in this ARP are recommended for inclusion in a Procurement Specification for
19、this type of accumulator. NOTE: Those requirements identified by the use of “shall” are considered to be essential requirements; those requirements identified by the use of “should” are considered to be optional requirements for inclusion in the Specification at the discretion of the Purchaser. In a
20、ddition, test methods for production acceptance and qualification purposes are also provided to permit a consistent approach for testing to be conducted for the different applications of this type of hydraulic accumulator. 1.2 Field of Application The accumulator is intended for use in military aero
21、space hydraulic systems with rated pressures of up to 8000 psi (55 158 kPa) and the following types as specified in AS5440: a. Type I: -65 to +160 F (-54 to +71 C) hydraulic fluid temperature b. Type II: -65 to +275 F (-54 to +135 C) hydraulic fluid temperature The accumulator is also intended for u
22、se in commercial aerospace hydraulic systems. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this specification to the extent specified herein. The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect
23、on the date of the purchase order. In the event of conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1.1 SA
24、E Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. ARP1383 Impulse Testing of Aerospace Hydraulic Actuators, Valves, Pressure Containers, and Similar Fluid System Co
25、mponents ARP4386 Terminology and Definitions for Aerospace Fluid Power, Actuation and Control Technologies AS4059 Aerospace Fluid Power - Cleanliness Classification for Hydraulic Fluids AS4941 Aerospace - General Requirements for Commercial Aircraft Hydraulic Components AS5440 Hydraulic Systems, Air
26、craft, Design and Installation, Requirements for AS8775 Hydraulic System Components, Aircraft and Missiles, General Specification for Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE ARP4378B Page
27、 5 of 25 2.1.2 U.S. Government Publications Available from the Document Automation and Production Service (DAPS), Building 4/D, 700 Robbins Avenue, Philadelphia, PA 19111-5094, Tel: 215-697-6257, http:/assist.daps.dla.mil/quicksearch/. MIL-PRF-27401 Propellant Pressurizing Agent, Nitrogen MIL-PRF-27
28、407 Propellant Pressurizing Agent, Helium MIL-STD-130 Identification Marking of U.S. Military Property MIL-STD-810 Environmental Engineering Constraints and Laboratory Tests 2.1.3 Code of Federal Regulations (CFR) Available from the U.S. Government Printing Office, 732 N. Capitol Street, NW Washingt
29、on, DC 20401, Tel: 202-512-0000, http:/www.gpoaccess.gov. 49CFR.173.306 Code of Federal Regulations Transportation Shippers General Requirements for Shipments and Packaging Limited Quantities of Compressed Gases 2.2 Related Publications The following publications are provided for information purpose
30、s only, and are not a required part of this SAE Aerospace document. 2.2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. ARP4379 Aerospace - Accumulator, Hydra
31、ulic, Cylindrical, Piston Separated ARP4553 Aerospace - Accumulator, Hydraulic, Self-Displacing ARP4752 Aerospace - Design and Installation of Commercial Transport Aircraft Hydraulic Systems ARP4925 Aerospace Design and Installation of Commercial Transport Helicopter Hydraulic Systems 2.2.2 FAR Publ
32、ications Available from Federal Aviation Administration, 800 Independence Avenue, SW, Washington, DC 20591, Tel: 866-835-5322, www.faa.gov. Order 8300.10 Appendix 3, Bulletin Type HBAW 02-01B: Flight Standards Handbook Bulletin for Airworthiness. Maintenance of Pressure Cylinders in use as Aircraft
33、Equipment. 2.3 Definitions Refer to ARP4386 for general hydraulic system terms that are used in this ARP. PURCHASER: The Purchaser is the organization that is responsible for providing the Procurement Specification for the accumulator. The Purchaser is typically an aircraft manufacturer, a modificat
34、ion center, or a system supplier (hydraulic or braking, for example). The Purchaser should provide the procurement specification for the accumulator. SUPPLIER: The Supplier is the manufacturer of the accumulator who is responsible for its design, production and qualification. Copyright SAE Internati
35、onal Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE ARP4378B Page 6 of 25 PROCUREMENT SPECIFICATION: The Procurement Specification is the document that includes the following: a. Specific performance and technical criteria
36、 b. Acceptance and qualification test requirements c. Reliability requirements d. Quality requirements e. Packaging requirements RATED SYSTEM PRESSURE: The rated system pressure is the nominal steady state pressure that is achieved: a. From the output pressure of the hydraulic system pumps - for an
37、accumulator used in the power generation system, or b. Due to thermal effects at the point of the actuation of a thermal relief valve - for an accumulator used to provide stored energy (for example, a brake accumulator) NOTES: 1. For military aerospace applications, Rated System Pressure is equivale
38、nt to the Pressure Class 2. For commercial aerospace applications, Rated System Pressure is equivalent to the Design Operating Pressure (DOP) PRECHARGE: The precharge is the factory sealed gas charge within the accumulator with the separator bottomed at the fluid end (usually specified as a pressure
39、 at a specific temperature). SEPARATOR: The separator is the part of the accumulator that separates the gas and the hydraulic system fluid. The separator comprises a welded bellows assembly and other devices to permit the separator to smoothly move within the accumulator body as hydraulic fluid is i
40、ngressed or expelled. VESSEL: The vessel is the portion of the accumulator that contains the pressurized hydraulic fluid and gas and separates both from the atmosphere. FILLING OIL VOLUME: The filling oil volume is the fluid that is stored in the accumulator fluid part when the accumulator separator
41、 is moved from the position at either zero pressure or a designated return pressure to where the separator is at the rated system pressure and at a prescribed temperature. SWEPT (EXPELLED) OIL VOLUME: The swept (expelled) oil volume is the fluid that is expelled from the accumulator fluid port when
42、the accumulator separator is moved from the position where the fluid stored in the accumulator is at the rated system pressure and at a prescribed temperature to either zero pressure or a designated return pressure. MAXIMUM SWEPT OIL VOLUME: The maximum swept oil volume is the maximum volume of hydr
43、aulic fluid that can be stored in the accumulator at either proof pressure or the system relief pressure at cold temperature, for example 40 F (40 C). To determine the maximum swept volume, the volume at both conditions must be calculated. The difference in gas volume between the precharge volume an
44、d the smaller of the proof pressure volume and the cold temperature relief pressure volume is the maximum swept oil volume. Real gas laws, including compressibility, should be used to calculate these volumes. VOLUMETRIC EFFICIENCY: The volumetric efficiency of an accumulator is the capability of the
45、 accumulator to expel the volume of hydraulic fluid with which it has been filled. This is expressed as an efficiency using the equation: Volumetric efficiency = (Swept (Expelled) Oil Volume/Filling Volume) x 100% Copyright SAE International Provided by IHS under license with SAENot for ResaleNo rep
46、roduction or networking permitted without license from IHS-,-,-SAE ARP4378B Page 7 of 25 ENDURANCE TEST: The endurance test is the test that is intended to determine the wear characteristics of the accumulator in order to determine if the element will operate satisfactory throughout its operational
47、lifetime. The endurance test comprises the realistic simulation of the operation of the accumulator over the life that has been declared for it, using an appropriate test rig. FATIGUE TEST: The fatigue test is the test that is intended to determine the fatigue strength of the accumulator. The fatigu
48、e test comprises the repeated application of pressure impulses using an appropriate test rig. 3. TECHNICAL REQUIREMENTS 3.1 General The accumulator shall be designed to meet the requirements of Federal Regulation 49CFR.173.306, Para.(f)(3). Factory precharged, welded bellows hydraulic accumulators that are intended to be used in military flight vehicle hydraulic systems shall conform to the general hydraulic components requirements of AS8775. Factory precharged, welded bellows hydraulic accumulators that are intended to be used in commercial aircraf
