ARMY A-A-52492 A-2009 SEAL ENGINE SHROUD《引擎罩密封》.pdf

1、 Beneficial comments, recommendations, additions, deletions, clarifications, etc. and any data that may improve this document should be sent to U.S. Army Tank-automotive and Armaments Command, ATTN: AMSRD-TAR-E/CM/DM/STND MS#268, 6501 E. 11 Mile Road, Warren, MI 48397-5000 or emailed to DAMI_STANDAR

2、DIZATIONconus.army.mil. Since contact information can change, you may want to verify the currency of this address information using the ASSIST Online database at http:/assist.daps.dla.mil. AMSC N/A FSC 2930 METRIC A-A-52492A October 5, 2009 SUPERSEDING A-A-52492 October 14, 1994 COMMERCIAL ITEM DESC

3、RIPTION SEAL, ENGINE SHROUD The General Services Administration has authorized the use of this commercial item description (CID) for all federal agencies. 1. SCOPE. This CID covers requirements for engine shroud seals made of treated fiberglass/aramid fabric, stitched over a corrosion resisting wire

4、 mesh core, intended for use in vehicles where high temperature conditions are present. 2. CLASSIFICATION. Items described in this CID shall be of the following types as specified (see 7.2). Type I - Round bulb, with the tail extension of the cover extending radially from the periphery of the core m

5、aterial. Type II - Rectangular bulb, with the tail extension of the cover parallel to the longer side of the rectangular core. 3. SALIENT CHARACTERISTICS 3.1 Materials. Unless otherwise specified herein or in the applicable engineering drawing (AED), the materials used shall be in accordance with th

6、e manufacturers material specifications/drawings. The use of recovered material made in compliance with regulatory requirements is acceptable providing that all requirements of this CID are met (see 4). 3.1.1 Thread. The thread used in stitching the plies of the tail shall be wire reinforced fibergl

7、ass with teflon coating and with a minimum breaking strength of 89 newtons (N). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-52492A 2 3.1.2 Cover cloth. Cover cloth shall be aramid/glass wire reinforced cloth with silicone rubber on the inside

8、, and coated on the outside with aluminum pigment silicone compound. The base fabric shall be plain weave aramid/glass cloth. Reinforcing wire shall be Inconel or stainless steel of the 300 series and wire diameter shall be American Wire Gage 36 (0.12 millimeter (mm) dia.). The cloth weight shall be

9、 0.90 kg per square meter (m2) (maximum). Wrap and fillings yarns shall be strands of wire and fiberglass completely covered by aramid fibers. The yarn shall be not less than 50 percent (%) aramid. The wire shall not show in the yarn or cloth. The inner and outer coating shall be silicone rubber Gra

10、de 5GE605A19B37E026F19Z of ASTM D2000. The value of Z shall be the minimum adhesion to the base fabric of 17.5 N per centimeter (cm) of width. 3.1.3 Cover coatings. When coatings are integrated into the weave of the cloth so that separation of tensile tongue is impossible, adhesion values are assume

11、d to exceed 26.3 N per cm. The inner and outer coating shall be complete and continuous. No exposed yarns shall be visible through the coating. The coating shall be smooth without blisters or depressions. The cloth after coating shall have the following properties: a. Thickness: Not less than 1.27 m

12、m b. Weight: 1.575 0.16 kg per m2c. Tear strength: Not less than 89 N 3.2 Design and construction. Seals shall be constructed to conform to the dimensions and form shown in the AED (see 7.2). These seals shall consist of a core of the shape specified (see 2) and a cover (see 3.1.2). The cover shall

13、overlap the core. Its edge shall extend to form the tail. 3.2.1 Core of the bulb. The core of the bulb shall be constructed of Inconel alloy or corrosion resisting stainless steel of the 300 series with not less than 16% chromium and 6% nickel. The filler shall be enclosed in a tubular mesh cover of

14、 the same material. The configuration and consistency of the filler, diameter of wire and size of mesh in filler and mesh cover shall be such as to provide the compression and recovery characteristics specified in 3.4, 3.5 and 3.6. When specified in the applicable drawings (see 7.2), the mesh cover

15、shall be drawn over the cut ends of the core, and engaged upon itself in such a way as to form a bound end without distorting the bulb of the seal. 3.2.2 Tail section. The tail section shall be furnished with bolt holes or with cut-outs, as specified in the AED. Sewing shall be of lock stitches and

16、shall count not less than 3 nor more than 5 stitches per running 25 mm. Sewing shall consist of two rows. One stitch line shall be closely adjacent to the core, the other stitch line shall be approximately 6 mm in from the edge of the tail. Bolt holes or cut-outs, when specified, shall not penetrate

17、 the stitching adjacent to the bulb. 3.2.3 Length. Length of seals without bolt holes or cut-outs shall not exceed 7.5 meters (m). 3.2.4 Bulb and tail. The dimensions of bulb and tail (overall width) for type I and type II seals shall be as specified in table I. Provided by IHSNot for ResaleNo repro

18、duction or networking permitted without license from IHS-,-,-A-A-52492A 3 TABLE I. Bulb and tail dimensions. Type Nominal bulb diameter (mm) Tolerance on overall width (bulb plus tail) dimension specified in AED (mm) I I I I I I 9.5 +1.6 12.5 +1.6 16.0 +1.6 25.4 +3.2 38.1 +3.2 44.5 +3.2 1.6 1.6 1.6

19、2.4 3.2 3.2 Nominal rectangular bulb size (mm) II 19.1 +1.6 by 38.1 +3.2 +3.2 3.3 Flame penetration. With the bulb of the finished seal compressed to 80% of its original nominal size between flat steel plates, the seal shall withstand an 1100 degrees Celsius (C) flame for 15 minutes with no penetrat

20、ion of flame beyond the sealing point and no flame remaining in the seal for more than 5 seconds after removal of the flame source. 3.4 Load compression. The seals shall be capable of being compressed under load and recovered within the load requirements and recovery limits specified in tables II an

21、d III at 24 C and 177 C, respectively. This shall be verified by applying to the type I seals the loads in an axial direction and for the type II seals by applying the loads parallel to the tail and with the tail held down. 3.5 Compression recovery at 24 C. The seals shall recover to the percentage

22、of the original bulb size after 15 minutes subsequent to being compressed for one minute. 3.6 Compression recovery at 177 C. The seals shall recover to the percentage of the original bulb size following each phase when subjected to the test as described below. The seals shall be compressed at the ap

23、plicable percentage of compression specified in table III, for 16 1/2 hours (phase 1) and for 5 hours (phase 2). The seals shall be allowed to cool for 15 minutes at ambient temperature following each phase. Following 60 5 minutes rest, phase 1 and phase 2 shall be repeated for a total of 4 cycles.

24、3.7 Tear strength. The cover shall exhibit a minimum tear strength of 48.9 N before heat test, when tested in accordance with the requirements of ASTM D2261. 3.8 Ozone Depleting Substances. Avoid using all EPA Class 1 Ozone depleting substances. 3.9 Identification markings. Unless otherwise specifie

25、d in the AED, identification markings shall be permanent and legible and shall include, as a minimum, the manufacturers CAGE code and part number and the AED part number (see 7.2). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-52492A 4 TABLE II

26、. Load compression. Nominal Load - N per linear cm of seal Type bulb size Percent compression (%) diameter (mm) 20% 33% 40% 60% I I I I I I 9.5 12.5 16.0 25.4 38.1 44.5 4.38 to 13.13 3.94 to 12.70 3.50 to 12.26 3.50 to 11.38 3.94 to 9.19 3.50 to 8.76 12.26 to 21.01 9.19 to 21.45 7.88 to 20.14 7.00 t

27、o 19.26 21.01 to 49.03 15.76 to 40.28 14.45 to 31.08 8.76 to 26.27 10.07 to 20.58 9.63 to 18.39 26.27 to 57.79 28.02 to 52.54 Nominal bulb size rectangular (mm) II 19.1 by 38.1 26.27 to 78.80 140.10 to 280.19 TABLE III. Percentage recovery. Type Nominal bulb size (mm) Percentage (%) Compression Reco

28、very 24 C 177 C I I I I I I II 25.4 9.5 12.5 16.0 38.1 44.5 19.1 by 38.1 33 33 33 33 40 40 40 90 90 90 90 90 90 90 75 75 75 75 80 80 80 4. REGULATORY REQUIREMENTS. The offeror/contractor is encouraged to use recovered materials to the maximum extent practicable, in accordance with paragraph 23.403 o

29、f the Federal Acquisition Regulation (FAR). 5. PRODUCT CONFORMANCE PROVISIONS 5.1 Responsibility for inspection. The contractor is responsible for the performance of all inspections (examinations and tests). 5.2 Contractor certification. The contractor shall certify and maintain substantiating evide

30、nce that the product offered meets the salient characteristics of this CID and that the product conforms to the producers own drawings, specifications, workmanship standards, and quality assurance practices. Items with known defects shall not be submitted for Government acceptance. The Government re

31、serves the right to require proof of such conformance prior to the first delivery and thereafter as may be otherwise provided for under the provisions of the contract. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-52492A 5 6. PACKAGING. Preserv

32、ation, packaging, packing, and marking for the desired level shall be as specified in the contract or order (see 7.2). 7. NOTES. (This section contains information of a general or explanatory nature that may be helpful, but is not mandatory.) 7.1 Addresses for obtaining copies of referenced document

33、s. 7.1.1 Non-Government publications. ASTM D2000 “Standard Classification System for Rubber Products in Automotive Applications”, and ASTM D2261 “Standard Test Method for Tearing Strength of Woven Fabrics by the Tongue (Single Rip) Method (Constant Rate-of-Extension Tensile Testing Machine)” are ava

34、ilable from www.astm.org or ASTM International, P.O. Box C700, West Conshohocken, PA 19428-2959. 7.2 Ordering data. Acquisition documents must specify the following: a. Title, number, and date of this CID. b. If required, the specific issue of individual documents referenced. c. Type of seal require

35、d. d. Applicable engineering drawing and revision letter, and part number. e. Applicable level of packaging, packing, and marking. 7.3 Cross-reference data. Seals, engine shroud conforming to this CID are interchangeable with seals, engine shroud conforming to MIL-S-45351B(AT), dated 26 March 1984.

36、MILITARY INTERESTS: CIVIL AGENCY COORDINATING ACTIVITY: GSA - FAS Custodian: Army - AT Preparing Activity: Army - AT (Project 2930-2009-002) NOTE: The activities listed above were interested in this document as of the date of this document. Since organizations and responsibilities can change, you should verify the currency of the information above using the ASSIST Online database at http:/assist.daps.dla.mil. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-