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1、AEROSPACE STANDARD Issued 1997-06 GLAND DESIGN, ELASTOMERIC O-RING SEALS, STATIC RADIAL AND FACE 800 PSI MAXIMUM SERVICE 1. SCOPE: This document establishes standard gland dimensions for low pressure static radial O-ring seal applications and provides recommendations for modifying these glands in sp
2、ecial applications. No provisions are made in this document for anti-extrusion devices. 1.1 Purpose: The purpose of this document is to provide the aerospace industry with standardized dimensional criteria for static radial elastomeric O-ring seal glands for a service pressure of 800 psi maximum. Th
3、is document supplements ARP1231. 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 on the date
4、of the purchase order. In the event of conflict between the text of this specification and references cited herein, the text of this specification takes precedence. Nothing in this specification, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1.1
5、 SAE Publications: Available from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001. AS568 Aerospace Size Standard for O-rings ARP1231Gland Design, Elastomeric O-ring Seals, General Considerations and Military Standard MS33581 AS4873 SAE Technical Standards Board Rules provide that: “This repor
6、t 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
7、 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,
8、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 ADDRES
9、S: http:/www.sae.org Reaffirmed 2007-12 Copyright SAE International Provided by IHS under license with SAELicensee=MHI - NAGOYA related to 3944000/3944000013 Not for Resale, 01/23/2008 23:43:43 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AS4873 - 2 - 2.1.2 ANSI Publ
10、ications: Available from ANSI, 11 West 42nd Street, New York, NY 10036-8002. ANSI B46.1 - 1962 Surface Texture 3. GENERAL REQUIREMENTS 3.2 Gland Configurations: 3.2.1 Standard Glands: Figure 1 and Table 1 depicts rod and bore-mounted radial and face seal O-ring seal glands. Standard dimensions for t
11、hese glands are tabulated in Figure 2. These dimensions are designed for use with seals conforming to AS568 tolerances except for the deviations in this document if any. Dimensions are computed in accordance with the criteria defined in Section 4 of this document and in ARP1231. 3.2.2 Exemption: Sta
12、ndard glands are not provided for the larger diameter bore-mounted applications. In these larger sizes, Diameter D becomes larger than the outside of the 0-ring seal. This condition makes the installation of a seal impractical. Bore-mounted seal glands have been provided up to those sizes where diam
13、eter D is equal to or greater than the seal ID plus 1/2 (seal OD - seal ID). 3.2.3 Modified Glands: The standard gland dimensions may be modified to achieve an optimum sealing configuration. In selecting or computing gland dimensions, the criteria defined in ARP1231 and in Section 4 of this document
14、 should be consulted. 3.3 Surface Texture: 3.3.1 Figure 1 defines the preferred surface texture to be used with the glands described in this document. The 63 and 40 in textures are satisfactory for most low pressure static applications. A 32 in texture may be required if there is relative motion bet
15、ween seal and gland sealing surfaces during operation. However, if this relative motion becomes excessive, the applications should be considered dynamic and ARP1233 consulted. 4. DESIGN CRITERIA: 4.1 O-ring Seal Stretch: 4.1.1 Minimum Stretch: Static seals should be stretched a minimum of 2% at inst
16、allation into the gland. This assures a snug fit in a short time for elastomers such as fluorocarbons which are slow to return to size after stretching. 4.1.2 Maximum Stretch: The as-installed seal stretch should be held to a low value consistent with the need for a 2% minimum stretch and with the g
17、land dimensional tolerances needed for manufacture. Excessive stretches can cause stress cracking during operation particularly with nitrile seals. The maximum stretch resulting from the standard gland dimensions in Figure 2 varies from 2.5 to 10% depending on size. Of the sizes listed, 85% have a m
18、aximum stretch of less than 5%. Consideration should be given to reducing the seal stretch when there is a possibility of seal stress cracking. Copyright SAE International Provided by IHS under license with SAELicensee=MHI - NAGOYA related to 3944000/3944000013 Not for Resale, 01/23/2008 23:43:43 MS
19、TNo reproduction or networking permitted without license from IHS -,-,- SAE AS4873 - 3 - Copyright SAE International Provided by IHS under license with SAELicensee=MHI - NAGOYA related to 3944000/3944000013 Not for Resale, 01/23/2008 23:43:43 MSTNo reproduction or networking permitted without licens
20、e from IHS -,-,- SAE AS4873 - 4 - TABLE 1 - Standard Gland Dimensions in Inches O-ring Size W Cross Section Nominal W Cross Section Actual L Gland Depth Squeeze Actual Squeeze % E Diametral Clearance (a & c) G Fuel & Engine Oil Uses G Vacuum & Gases R Groove Radius Eccentricity Max (b) 4 through 50
21、110 through 178 210 through 284 325 through 395 425 through 475 1/16 3/32 1/8 3/16 1/4 0.070 .003 0.103 .003 0.139 .004 0.210 .005 0.275 .006 0.050 to 0.054 0.074 to 0.080 0.101 to 0.107 0.152 to 0.162 0.201 to 0.211 0.013 to 0.023 0.020 to 0.032 0.028 to 0.042 0.043 to 0.063 0.058 to 0.080 19 to 32
22、 20 to 30 20 to 30 21 to 30 21 to 29 0.002 to 0.010 0.002 to 0.010 0.003 to 0.011 0.003 to 0.011 0.004 to 0.012 0.101 to 0.107 0.136 to 0.142 0.177 to 0.187 0.270 to 0.290 0.342 to 0.362 0.082 to 0.088 0.117 to 0.123 0.157 to 0.163 0.247 to 0.253 0.322 to 0.328 0.005 to 0.015 0.005 to 0.015 0.010 to
23、 0.025 0.020 to 0.035 0.020 to 0.035 0.002 0.002 0.003 0.004 0.005 a. Clearance gap must be held to a minimum consistent with design requirements for temperature range variation. b. Total indicator reading between groove and adjacent bearing surface. c. Reduce maximum diametral clearance 50% when us
24、ing Silicone 0-rings. Copyright SAE International Provided by IHS under license with SAELicensee=MHI - NAGOYA related to 3944000/3944000013 Not for Resale, 01/23/2008 23:43:43 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AS4873 - 5 - Copyright SAE International Provi
25、ded by IHS under license with SAELicensee=MHI - NAGOYA related to 3944000/3944000013 Not for Resale, 01/23/2008 23:43:43 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AS4873 - 6 - Copyright SAE International Provided by IHS under license with SAELicensee=MHI - NAGOYA
26、related to 3944000/3944000013 Not for Resale, 01/23/2008 23:43:43 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AS4873 - 7 - Copyright SAE International Provided by IHS under license with SAELicensee=MHI - NAGOYA related to 3944000/3944000013 Not for Resale, 01/23/200
27、8 23:43:43 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AS4873 - 8 - Copyright SAE International Provided by IHS under license with SAELicensee=MHI - NAGOYA related to 3944000/3944000013 Not for Resale, 01/23/2008 23:43:43 MSTNo reproduction or networking permitted w
28、ithout license from IHS -,-,- SAE AS4873 - 9 - Copyright SAE International Provided by IHS under license with SAELicensee=MHI - NAGOYA related to 3944000/3944000013 Not for Resale, 01/23/2008 23:43:43 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AS4873 - 10 - Copyrig
29、ht SAE International Provided by IHS under license with SAELicensee=MHI - NAGOYA related to 3944000/3944000013 Not for Resale, 01/23/2008 23:43:43 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AS4873 - 11 - Copyright SAE International Provided by IHS under license wit
30、h SAELicensee=MHI - NAGOYA related to 3944000/3944000013 Not for Resale, 01/23/2008 23:43:43 MSTNo reproduction or networking permitted without license from IHS -,-,- SAE AS4873 - 12 - 4.2 0-ring Seal Squeeze: 4.2.1 To avoid assembly problems and to avoid leakage, low pressure (800 psi maximum) stat
31、ic 0-ring seal glands should be designed to achieve nominal and minimum squeezes as listed in Tables 1 and 2. These values have been used in computing the gland dimensions of Figure 2. Minimum squeeze should be calculated by considering the following factors: a.Diametral tolerances b.Eccentricities
32、c.Offset d.Seal cross section reduction due to stretch Offset refers to the condition where the rod has shifted in the bore to the extent that the rod and bore are in contact. TABLE 2 - 0-ring Seal Squeeze Nominal Cross Section Diameter Per AS568 (W) Maximum Squeeze % of W Nominal Minimum Squeeze .0
33、70 in .103 in .139 in .210 in .275 in 32 30 30 30 29 .013 in .020 in .028 in .043 in .058 in Copyright SAE International Provided by IHS under license with SAELicensee=MHI - NAGOYA related to 3944000/3944000013 Not for Resale, 01/23/2008 23:43:43 MSTNo reproduction or networking permitted without li
34、cense from IHS -,-,- SAE AS4873 - 13 - 4.3 O-ring Seal Swell: 4.3.1 To accommodate O-ring seal swell, gland widths should be designed to achieve a mean gland volume equal to 130% of the O-ring seal free state volume. This will permit glands to be used with several different seal materials and operat
35、ing fluids. The glands in Figure 2 provide a minimum gland volume which is 125 to 135% of the O-ring seal free state volume. If the adjacent structure is strong enough, these glands can be used with all material/fluid combinations, including those where the fully soaked O-ring seal volume exceeds th
36、e gland volume. NOTE: High temperatures and overfill can result in the rubber recurring to the groove shape resulting in a lack of sufficient squeeze at extreme cold temperatures. 4.4 Diametral Clearances: 4.4.1 The rod-to-bore diametral clearances must be controlled to prevent O-ring seal extrusion
37、 during operation. The diametral clearances listed in Table 3 are suitable for use with most elastomers at operating pressures up to 800 psi. The glands in Figure 2 incorporate these diametral clearances. PREPARED BY SAE SUBCOMMITTEE AE-5B, ENGINE RELATED COMPONENTS & AIRFRAME MOUNTED PUMPS OF COMMI
38、TTEE AE-5, AEROSPACE FUEL, OIL & OXIDIZER SYSTEMS TABLE 3 - Diametral Clearances TABLE 3A - Inches Seal Cross Section (W) Bore to Rod Clearances .070 .103 .139 .210 .275 .002-.010 .002-.010 .003-.011 .003-.011 .004-.012 TABLE 3B - Millimeters Seal Cross Section (W) Bore to Rod Clearances 1.78 2.62 3.53 5.33 6.98 .051-.254 .051-.254 .076-.280 .076-.280 .101-.305 Copyright SAE International Provided by IHS under license with SAELicensee=MHI - NAGOYA related to 3944000/3944000013 Not for Resale, 01/23/2008 23:43:43 MSTNo reproduction or networking permitted without license from IHS -,-,-