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 revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2017 SAE International All rights reserved. No part of this p
3、ublication 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: +1 724-776-497
4、0 (outside USA) 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:/standards.sae.org/ARP4763 AEROSPACE RECOMMENDED PRACTICE ARP4763 Issued 2017-09 Aerospace - General Requirements
5、for Hydraulic Relief Valves RATIONALE This document was developed to assist the system designer in specifying the requirements for a hydraulic relief valve that prevents the development of excessive pressure. TABLE OF CONTENTS 1. SCOPE 3 1.1 Purpose . 3 2. REFERENCES 3 2.1 Applicable Documents 3 2.1
6、.1 SAE Publications . 3 2.1.2 U.S. Military Specifications and Publications 4 2.2 Definitions 4 3. REQUIREMENTS . 6 3.1 General 6 3.2 Hydraulic System Pressures . 6 3.3 Performance Requirements 6 3.3.1 Rated Flow 6 3.3.2 Cracking Pressure . 6 3.3.3 Full Flow Pressure (Pressure Drop at Rated Flow) .
7、6 3.3.4 Reseat Pressure . 7 3.3.5 Full Flow Response Time 7 3.3.6 Stability 7 3.3.7 Leakage. 7 3.4 Environmental Requirements 7 3.4.1 General 7 3.4.2 Operating Temperature Ranges . 7 3.4.3 Vibration, Shock, and Acceleration . 8 3.4.4 Other Environmental Requirements 8 3.5 Design and Construction . 8
8、 3.5.1 Dimensions and Mounting Provisions . 8 3.5.2 Inlet/Outlet Flow Paths 8 3.5.3 Weight . 8 3.5.4 Hydraulic Fluid . 8 3.5.5 Fluid Cleanliness . 9 3.5.6 Seals . 9 3.5.7 Corrosion Protection 9 3.5.8 Storage 9 SAE INTERNATIONAL ARP4763 Page 2 of 16 3.6 Identification Marking 9 3.6.1 Identification M
9、arking for Commercial Applications 9 3.6.2 Identification Marking for Military Applications 9 3.7 Endurance . 10 3.8 Structural and Operational Requirements . 10 3.8.1 Proof Pressure 10 3.8.2 Ultimate Pressure 10 3.8.3 Pressure Impulse 10 3.9 Reliability . 10 4. QUALITY ASSURANCE PROVISIONS 10 4.1 R
10、esponsibility of Inspection . 10 4.2 Classification of Tests . 10 4.3 General Testing Requirements . 11 4.4 Acceptance Tests 11 4.4.1 Preparation for Shipment 11 4.4.2 Storage and Packing . 11 4.5 Qualification Tests . 11 4.6 Examination of the Product . 12 4.7 Test Methods 12 4.7.1 Temperature 12 4
11、.7.2 Fluid Cleanliness . 12 4.8 Tests . 12 4.8.1 Fluid Immersion . 12 4.8.2 Electro-Conductive Bonding 12 4.8.3 Cycling . 12 4.8.4 Proof Pressure 12 4.8.5 Leakage Test 13 4.8.6 Relief Valve Performance . 13 4.8.7 Extreme Temperature Tests . 13 4.8.8 Endurance Cycling 13 4.8.9 Pressure Impulse 14 4.8
12、.10 Vibration, Shock, and Acceleration . 14 4.8.11 Ultimate Pressure 14 4.8.12 Other Environmental Testing 14 5. NOTES 15 5.1 Revision Indicator 15 5.2 Factors Affecting Test Results 15 5.2.1 Fluid Particulate Contamination 15 5.2.2 Pump Ripple 15 5.3 Types of Relief Valves . 15 5.3.1 Single Stage R
13、elief Valve 15 5.3.2 Dual Stage Relief Valve 16 Figure 1 Flow versus pressure 5 Table 1 Qualification testing . 11 SAE INTERNATIONAL ARP4763 Page 3 of 16 1. SCOPE This SAE Aerospace Recommended Practice (ARP) is intended as a guide to define the requirements for aerospace hydraulic relief valves, in
14、cluding details pertinent to the design, performance, fabrication, and testing of the relief valves. NOTE 1: This ARP is for hydraulic system full-flow relief valves; ARP4835 has been developed to specifically cover thermal relief valves. NOTE 2: This document does not cover the modification of crac
15、king pressure by external input; either hydraulic, electric, or pneumatic. 1.1 Purpose This document is intended for use in conjunction with the procurement specification to be prepared by the purchaser in which the valve configuration, system fluid and other parameters for the particular applicatio
16、n are defined. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this document 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 on the date of the purchase order. I
17、n 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 SAE Publications Available from SAE In
18、ternational, 400 Commonwealth Drive, Warrendale, PA 15091 0001, Tel: 877-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org. AIR4543 Aerospace Hydraulics and Actuation Lessons Learned ARP1383 Aerospace - Impulse Testing of Hydraulic Components ARP4386 Terminology and Defi
19、nitions for Aerospace Fluid Power, Actuation and Control Technologies ARP4835 Aerospace Fluid Power-Hydraulic Thermal Expansion Relief Valves AS478 Identification Marking Methods AS1241 Fire Resistant Phosphate Ester Hydraulic Fluid for Aircraft AS1300 Port - Ring Locked Fluid Connection Type, Stand
20、ard Dimensions For AS4059 Aerospace Fluid Power - Contamination Classification for Hydraulic Fluids AS4716 Gland Design, O-ring and Other Elastomeric Seals AS4941 Aerospace - General Requirements for Commercial Aircraft Hydraulic Components AS5202 Port or Fitting End, Internal Straight Thread, Desig
21、n Standard AS5857 Gland Design, O-ring and Other Elastomeric Seals, Static Applications AS8775 Hydraulic System Components, Aircraft and Missiles, General Specification For SAE INTERNATIONAL ARP4763 Page 4 of 16 2.1.2 U.S. Military Specifications and Publications Copies of these documents are availa
22、ble at http:/quicksearch.dla.mil. MIL-PRF-83282 Hydraulic Fluid, Fire Resistant, Synthetic Hydrocarbon Base, Aircraft MIL-PRF-87257 Hydraulic Fluid, Fire Resistant, Low Temperature, Synthetic Hydrocarbon Base, Aircraft and Missile MIL-STD-130 Identification Marking of U.S. Military Property 2.2 Defi
23、nitions Refer to ARP4386 for general hydraulic systems terms that are used in this recommended practice. The following terms used in this document are defined as follows: RELIEF VALVE: A relief valve is a pressure sensing valve which ports hydraulic fluid from inlet to outlet at a preset pressure th
24、at is higher than the normal hydraulic system pressure in order to prevent overpressure of the system. THERMAL RELIEF VALVE: A relief valve which ports small amounts of hydraulic fluid to return at a preset pressure to prevent overpressure caused by thermal expansion within a sub-circuit isolated fr
25、om the main system relief valve. CRACKING PRESSURE: Cracking pressure is the pressure setting at which the relief valve opens and begins to flow a minimal quantity. Typically a flow of 20cc/min would be used to define flow at cracking pressure on a system pressure relief valve. This value should be
26、evaluated and defined in the procurement specification. Since cracking pressure is difficult to quantify, it should not be used as a performance requirement, but for reference only. See Figure 1. FLOW PRESSURE: Flow pressure is the differential pressure at which a specified flow occurs. See Figure 1
27、. FULL FLOW PRESSURE: The differential pressure at which the rated flow occurs. See Figure 1. RATED FLOW: The flow that the relief valve should be designed for. See Figure 1. RESEAT PRESSURE: Reseat pressure is the pressure that corresponds to the leakage allowed on decreasing pressure after an even
28、t has caused the valve to reach or exceed the cracking pressure. See Figure 1. NTERNAL LEAKAGE: Leakage of fluid from inlet to outlet at a specified pressure. EXTERNAL LEAKAGE: Leakage external to the pressure vessel. STATIC LEAKAGE: External fluid leakage with the unit statically pressurized. SAE I
29、NTERNATIONAL ARP4763 Page 5 of 16 Figure 1 - Flow versus pressure DESIGN OPERATING PRESSURE (DOP): Design operating pressure is the normal maximum steady state pressure of the relief valve. Excluded are: Reasonable tolerances and transient pressure effects such as may arise from acceptable pump ripp
30、le, or Reactions to system functioning or demands that may affect fatigue NOTE: This term is used in commercial aircraft and helicopter applications. For military applications, the term “rated pressure” can be substituted. PROCUREMENT SPECIFICATION: The procurement specification is the document that
31、 includes the following: Technical Requirements Acceptance and Qualification Test Requirements SAE INTERNATIONAL ARP4763 Page 6 of 16 Reliability Requirements Quality Requirements Packaging Requirements ENDURANCE TEST: The endurance test is defined as the test that is intended to determine the wear
32、characteristics of the relief valve in order to determine if it will perform satisfactorily throughout its operational life. FATIGUE TEST: The fatigue test is defined as the test that is intended to validate the fatigue strength of the relief valve by repeated application of pressure impulses. 3. RE
33、QUIREMENTS 3.1 General The requirements of AS8775, for military applications, or AS4941, for commercial applications should apply as requirements of this document, with the exceptions specified herein. When this document and the applicable above referenced specifications conflict, those documents sh
34、ould govern. 3.2 Hydraulic System Pressures The procurement specification should state the Design Operating Pressure (DOP) for the inlet and outlet sides of the relief valve. In addition, the backpressure at the outlet side that the relief valve will operate against should be specified in order to a
35、ssist in the definition of the performance of the relief valve and its integration into the valves hydraulic system. 3.3 Performance Requirements The relief valve should be capable of meeting all the performance requirements specified below unless otherwise specified by the procurement specification
36、. The performance specification should define the temperature at which the following requirements are to be met. 3.3.1 Rated Flow The rated flow should be specified in the procurement specification. 3.3.2 Cracking Pressure The cracking pressure should be designed as close to the full flow pressure s
37、pecified in 3.3.3 as practical. The cracking pressure should be measured for information only, and not be controlled in the procurement specification as a pressure with a tolerance. 3.3.3 Full Flow Pressure (Pressure Drop at Rated Flow) The full flow pressure should occur on increasing pressure at t
38、he rated flow. The full flow pressure should be specified in the procurement specification taking into account: The maximum allowable transient pressure of the system The backpressure of the hydraulic system 135% of DOP Maximum SAE INTERNATIONAL ARP4763 Page 7 of 16 3.3.4 Reseat Pressure The reseat
39、pressure should occur on decreasing pressure at a minimum pressure not to be less than 104% of the DOP (normally between 106 to 109% of DOP). The reseat pressure should be defined in the procurement specification as a pressure and a leakage rate. The leakage rate should be expressed as a maximum, an
40、d be a minimum 250% higher than the leakage specified at DOP in 3.3.7.2. 3.3.5 Full Flow Response Time The full flow response time should be defined by the procuring activity. 3.3.6 Stability The relief valve should operate smoothly and should not exhibit any indication of chattering or instability
41、at any operating condition. This is verified during acceptance testing by the requirements of 4.8.3 and 4.8.6. NOTE 1: The stability of the valve is sensitive to the amount of hydraulic flow on the high pressure side and to the percentage of valve opening. NOTE 2: The valve should have an internal d
42、amping means as it is a key element of maintaining the stability of the pressure relief valve. 3.3.7 Leakage 3.3.7.1 External Leakage There should be no external leakage sufficient to form a drop from any static seal or boss under any applied pressure from zero to ultimate pressure. 3.3.7.2 Internal
43、 Leakage The procurement specification should define the internal leakage rate for the relief valve for pressures between 0 up to the DOP. 3.4 Environmental Requirements 3.4.1 General The relief valve should not suffer any damage, deterioration, or degradation of performance except as allowed herein
44、 when subjected to any of the environmental requirements as specified in AS4941 or AS8775, as applicable. 3.4.2 Operating Temperature Ranges The procurement specification should define the normal, extreme and survival temperature requirements. 3.4.2.1 Hydraulic Fluid Temperature Range For military a
45、pplications, the relief valve should be designed to operate at the hydraulic fluid temperature range for the required system type as listed below: Type I: -65 to +160 F (-54 to +71 C) fluid temperature Type II: -65 to +275 F (-54 to +135 C) fluid temperature Type III: -65 to +450 F (-54 to 232 C) fl
46、uid temperature For commercial applications, the operating hydraulic fluid temperature range should be as specified by the procurement specification. SAE INTERNATIONAL ARP4763 Page 8 of 16 3.4.2.2 Ambient Temperature Range The procurement specification should define the ambient temperature range for
47、 the relief valve. 3.4.3 Vibration, Shock, and Acceleration The relief valve shall withstand the vibration, shock, and acceleration levels as specified in the procurement specification. 3.4.4 Other Environmental Requirements Additional requirements, based on the use and the environment of the relief
48、 valve, should be considered and specified as required by the procurement specification. For example, additional requirements could include: a. Humidity b. Water proofness c. Fluids susceptibility d. Sand and dust e. Fungus resistance f. Salt spray g. Icing Unless otherwise specified in the procurem
49、ent specification, these requirements should be as per the applicable sections of AS8775 for military applications and AS4941 for commercial applications. 3.5 Design and Construction The materials and processes used in the design and fabrication of components should be of high quality, suitable for the purpose and should conform to the applicable specifications. Materials conforming to the suppliers mater
