SAE ARP 5316D-2014 Storage of Elastomer Seals and Seal Assemblies Which Include an Elastomer Element Prior to Hardware Assembly.pdf

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 theref

2、rom, 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 2014 SAE International All rights reserved. No part of this pub

3、lication 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: +1 724-776-4970

4、(outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/ARP5316DAEROSPACERECOMMENDED PRACTICEARP5316 REV. DIssued 1998-11 Revised 2014-10 Su

5、perseding ARP5316C Storage of Elastomer Seals and Seal Assemblies Which Include an Elastomer Element Prior to Hardware Assembly RATIONALEThis revision addresses the users request to add an additional Table summarizing shelf life for polymer type and explains how to correctly calculate elastomer age.

6、 1. SCOPE This SAE Aerospace Recommended Practice (ARP) addresses the general requirements for data recording procedures, packaging, and storing of elastomeric seals and seal assemblies which include an elastomeric element prior to the seal being assembled into hardware components. It applies specif

7、ically to those elastomeric seals and seal assemblies packaged shortly after manufacture. The storage period prior to installation of the elastomeric seals and seal assemblies into hardware components is commonly referred to as shelf life. The information contained in this ARP is intended to be util

8、ized by those organizations who do not have specific requirements or recommendations already in place for the control of elastomeric seals and seal assemblies. This ARP can be specified in control, storage, and procurement documents. However, when the requirements of this document are in conflict wi

9、th the customers requirements or specifications, the requirements of the customers detailed specification shall govern. 1.1 Disclaimer This document does not establish limitations or storage times for assembled components nor the operating life of said components.2. REFERENCES 2.1 Applicable Documen

10、ts 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. In theevent of conflict between the text of this doc

11、ument 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. SAE INTERNATIONAL ARP5316D Page 2 of 17 2.1.1 SAE Publications Available from SAE International,

12、 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.AMS2817 Packaging and Identification, Preformed Packings AS1933 Age Controls for Hose Containing Age-Sensitive Elastomeric Material 2.1.2 ASTM Publications Availab

13、le from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org.ASTM D1418 Standard Practice for Rubber and Rubber Latices - Nomenclature 2.1.3 Electric Power Research Institute Publications Available from EPRI, 3420 Hillview Avenue

14、, Palo Alto, CA 94304, .NP-6608 Shelf Life of Elastomeric Components 2.1.4 U.S. Government Publications Available from DLA Document Services, Building 4/D, 700 Robbins Avenue, Philadelphia, PA 19111-5094, Tel: 215-697-6396, http:/quicksearch.dla.mil/.AFML-TR-67-235 Literature Survey on the Effects o

15、f Long-Term Shelf Aging of Elastomer Materials ANA Bulletin 438 Age Control of Age-Sensitive Elastomeric Items DOD 4140.27.M Shelf Life Management Manual MIL-HDBK-695 Rubber Products: Recommended Shelf Life MIL-STD-1523 Age Control of Age-Sensitive Elastomeric Materials 2.2 Definitions 2.2.1 ELASTOM

16、ER: A material that possesses elastic properties and has undergone vulcanization and/or conversion into a finished product. 2.2.2 SEAL: An elastomeric finished product or an assembly with an elastomeric element which prevents the excursion of media on one side of the product from migrating to the ot

17、her side. 2.2.3 STORAGE LIFE: The maximum period of time, starting from the time of manufacture, that an elastomeric seal element, appropriately packaged, may be stored under specific conditions, after which time it is regarded as unserviceable for the purposes for which it was originally manufactur

18、ed. The time of manufacture is the time of cure for thermoset elastomers or the time of conversion into a finished product for thermoplastic elastomers. 2.2.2 HARDWARE COMPONENT: The unit in which the elastomeric seal element is placed. SAE INTERNATIONAL ARP5316D Page 3 of 17 3. BACKGROUND Listed be

19、low is the background information which led to the creation of this Aerospace Recommended Practice. 3.1 MIL-STD-1523 Age control was imposed on elastomers used in critical sealing devices of aircraft hydraulic, lubricating, and fuel systems after World War II. Several different requirements and spec

20、ifications were implemented in the years following the war until 1958 when ANA Bulletin 438 was released. This bulletins purpose was to collect all previous requirements for age control in one document and to make it easier for various agencies and contractors to effectively implement age control. H

21、owever, confusion in interpretations resulted in abuses, cost increases and inconsistently imposed exceptions. Many other programs were then undertaken to study age control. The results of many of these were summarized in the Air Force report, AFML-TR-67-235. The conclusion of the studies summarized

22、 in this report and others that were in progress was that the overall properties of elastomeric materials were much improved over the materials initially evaluated and age control should be made less restrictive. As a result of this information, MIL-STD-1523 was released in 1973 and superseded ANA B

23、ulletin 438. One of the basic requirements of the new document was to provide a cure date limitation of twelve quarters from cure date to acceptance of the seals by the original procuring activity, whether a government agency, a first or second contractor or an organization which assembles seal and

24、hardware kits. In all cases, the use of cure date was intended to provide for good FIFO (First In - First Out) warehousing procedures. On February 1, 1984, MIL-STD-1523A was issued to supersede MIL-STD-1523. This revision was targeted at eliminating the confusion in interpretation of the previous do

25、cument. It also extended cure date requirements from 12 quarters to 40 quarters. MIL-STD-1523A controlled the age of elastomers only at time of acceptance by the government. This meant that the cure date of each elastomer had to be known at the time a system was accepted by the government. Even with

26、 the clarifications of MIL-STD-1523A, confusion still existed and the discussion regarding the need for age control continued. 3.2 EPRI NP-6608 In June, 1989, Bruce Boyum and Jerral Rhoads presented an IEEE Paper: “Elastomer Shelf Life: Aged Junk or Jewels“ - IEEE Transactions on Energy Conversion,

27、Vol.4, No.2, pp 191-203, June, 1989. After a detailed review of the information from previous studies and the age control documents including MIL-HDBK-695C, they concluded that age control limits were very conservative and shelf life could be extended as long as proper storage conditions were mainta

28、ined. This was followed up in May, 1994 by EPRI NP-6608, “Shelf Life of Elastomeric Components“. The conclusion of this detailed study was that with proper storage, shelf life for elastomer seals could be extended to 32 years. 3.3 AS1933A Based upon the data from the numerous studies concerning age

29、control and shelf life, MIL-STD-1523A was canceled on January 30, 1995 - without replacement but reference was made to AS1933A. This action, in essence, released aerospace elastomers from age control. In the time since the cancellation of MIL-STD-1523A confusion has reigned. Contractors are not awar

30、e of the history of age control and still insist on it. Quality organizations are not only still insisting on age control but are now using AS1933A for seals or referring to MIL-HDBK-695C. Some of the insistence for age control is due to the requirement that the latest revision of specifications mus

31、t be used and if age control or cure date requirements are removed, there is no traceability to specification revisions. In addition, organizations are concerned about FIFO requirements being maintained. SAE INTERNATIONAL ARP5316D Page 4 of 17 3.4 ARP5316 To address the needs of contractors and to a

32、lleviate the confusion created by the cancellation of MIL-STD-1523A, ARP5316 was issued. This recommended practice addresses elastomeric seal components and offers a control document for those organizations which require one. It includes recommended shelf life limits that are consistent with the dat

33、a from the cumulative studies on age control. It addresses the need for traceability and proper storage of elastomeric components of seals. It also provides a document that addresses seals not hoses, rubber boots, etc. It provides a reference source for Quality Organizations to work with. The recomm

34、ended storage times are based upon industry input regarding practical storage limits based upon FIFO requirements. Most users of the elastomers addressed in this ARP will find that the times listed in the document are beyond the time periods utilized in FIFO programs. More importantly, proper storag

35、e and traceability are emphasized since these are the key elements in promoting long shelf life and ensuring that the elastomeric seal components meet the latest revision of a specification. 3.5 MIL-HDBK-695D This recently released revision directs the reader to ARP5316 for questions concerning elas

36、tomer seal shelf life. 3.6 DOD 4141.27.M The DOD Shelf Life Management Manual uses ARP5316 as its key reference for elastomer seal shelf life. 4. PACKAGING 4.1 Unless otherwise specified by the customer at the time of order, the elastomeric seal or seal assembly shall be packaged:a. in individually

37、sealed envelopes by the manufacturer, or b. in individually sealed packets in multiple envelopes by the manufacturer provided that individually packaged elastomeric seals or assemblies can be removed without affecting the seal integrity of the other packets. c. If the parts are repackaged by a distr

38、ibutor, the manufacturer will ship the properly identified parts to the distributor then the responsibility for the parts shifts to the distributor since the manufacturer cannot ensure that the parts will be properly packaged with minimum exposure to environmental conditions. The packaging shall be

39、carried out in an atmosphere in which the relative humidity is not greater than 65%. Contamination by oil, grease, etc., shall be avoided. Seal assemblies (all components) shall be packaged in the same sealed envelope so that all elements of the assembly are present when the package is opened. 4.2 P

40、ackaging Materials All packaging materials shall be free of copper naphthenates or creosote preservatives which can degrade rubber. Suitable materials include Kraft bags and opaque polyethylene bags more than 0.075 mm thick. Opaque packaging is required. Metal foil bags can be used provided they are

41、 salt free. NOTE: Phosphate ester hydraulic fluids and polyol ester based gas turbine lubricants soften and compromise polyethylene bags so care should be taken to avoid exposure of polyethylene storage bags to fluids. SAE INTERNATIONAL ARP5316D Page 5 of 17 4.3 Labeling Each package or container sh

42、all be labeled with the following information which shall be visible from the outside of the package without breaking the seal: a. Manufacturers part number; b. Specification number and Revision level; c. Customers part number and/or contract number (if requested); d. Quantity in package; e. Manufac

43、turers name and/or identity number (such as CAGE Code); f. Quarter and Year of cure or manufacturer of the rubber component (e.g., July to September 1997 = 3Q97); g. Manufacturers batch number; h. Rubber class designation per ASTM D1418; i. Packagers name (if different from manufacturer) and package

44、d date. Expiration date will be added to the label for direct military procurement. It is not required to be on the label and will be added only when Purchaser specifically requests the addition because of direct military procurement. AMS2817 allows individually packaged parts to be supplied to a di

45、stributor who can then allocate them to orders: If parts are purchased from the manufacturer under one contract number and sold, without being repackaged, by the supplier to the consumer under a different contract number, the original contract number shall be crossed out and the new contract number

46、applied in the heat seal area of the envelope. Thus cradle to grave traceability and maximum protection of the elastomer seal element is guaranteed.5. STORAGE 5.1 Temperature The storage temperature shall be below 100 F (38 C), except when higher temperatures are caused by temporary climate changes,

47、 and articles shall be stored away from direct sources of heat such as boilers, radiators, and direct sunlight.NOTE: If the storage temperature is below 59 F (15 C), care should be exercised during the handling of stored articles as they may have stiffened and become susceptible to distortion if not

48、 handled carefully. The temperature of articles stored below 59 F (15 C) shall be raised to approximately 68 F (20 C) throughout their mass before being installed into a component. 5.2 Humidity The relative humidity shall be such that given the variations of temperature in storage, condensation does

49、 not occur. In any event, if the elastomers are not stored in sealed moisture proof bags, the relative humidity of the atmosphere in storage shall be less than 75% r h, or if polyurethanes are being stored, shall be less than 65% r h. SAE INTERNATIONAL ARP5316D Page 6 of 17 5.3 Light Elastomeric seals shall be protected from light sources, in particular direct sunlight or intense artificial light having an ultravio