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 2015 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:/www.sae.org/technical/standards/J151_201508 SURFACE VEHICLE RECOMMENDED PRACTICE J151 AUG2015 Issued 1970-01 Revi
5、sed 2015-08 Superseding J151 SEP2008 Pressure Relief for Cooling SystemRATIONALE This document has been reviewed and revised by adding clarifying statements to the text accompanying Figure 1. 1. SCOPE This SAE Recommended Practice specifies requirements for pressure relief means and pressure relief
6、rating identification for cooling systems of liquid-cooled engines to reduce the possibility of injuries during opening of the cooling system. 2. REFERENCES 2.1 Applicable Document The following publication forms a part of this specification to the extent specified herein. Unless otherwise indicated
7、, the latest issue of SAE publications shall apply. 2.1.1 SAE Publication 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.SAE J164 Radiator Caps and Filler Necks 3. DEFINITIONS 3
8、.1 COOLING SYSTEM CAP Herein referred to as cap, means a device which closes the opening used to add coolant to the pressure section of the engine cooling system. 3.2 PRESSURE RELEASE MECHANISM Means a device which, when activated, allows the pressure in a cooling system to be released. 3.3 LEGIBLE
9、Means readable under daylight lighting conditions by an observer having 20/20 vision (Snellen) whose eyepoint is located in proximity to the marked surface. SAE INTERNATIONAL J151 AUG2015 Page 2 of 3 4. APPLICATION This document applies to passenger cars, multipurpose passenger vehicles, trucks, cha
10、ssis cabs, buses, construction vehicles, and to equipment produced for motor vehicles manufactured after the effective date of this document. 5. REQUIREMENTS 5.1 Pressure relief which is actuated without operator action for the purpose of limiting peak pressures in the cooling system should be accom
11、plished in a manner which limits, to the extent practicable, the risk of injury. Pressure relief which is actuated by the operator for the purpose of safe removal of the cap must conform to 5.2 or 5.3, except as provided in 5.4. 5.2 Pressure release mechanism incorporated in the cap and/or filler ne
12、ck shall conform to one of the following: 5.2.1 If pressure relief can be accomplished by cap rotation, one of the following mechanisms must be incorporated to prevent cap removal prior to pressure relief. 5.2.1.1 Either mechanical stop that prevents cap removal by rotation only, requiring the cap t
13、o be moved axially and further rotated, for removal. 5.2.1.2 Or a design which requires that the cap be rotated at least 1 and 1/2 turns after pressure relief before the cap can be removed. 5.2.2 If pressure relief is accomplished through other than cap rotation, a means shall be provided to prevent
14、 removal of the cap before the pressure relief is actuated. 5.3 Pressure release mechanism not incorporated in the cap and/or filler neck shall have legibly and permanently marked on or adjacent to the cap instructions for relief of system pressure prior to cap removal. 5.4 “Sealed cooling system“ w
15、hich the manufacturer recommends servicing at stated intervals and which does not meet the requirements of 5.2 and 5.3 shall require use of a tool to accomplish cap removal. The words “Do Not Remove - See Manufacturers Instructions“ shall be legibly and durably marked on or immediately adjacent to t
16、he cap. 6. The cap or pressure relief valve assembly shall be legibly and durably marked with its normal pressure rating and notation “Warning Do Not Remove Hot.“ Manufacturers may also elect to use ISO symbols to replace the verbiage, thus avoiding issues with language. SAE INTERNATIONAL J151 AUG20
17、15 Page 3 of 3 Figure 1 - Section view of typical pressure cap The area between the 2 O-Rings is open to the atmosphere. This passage may be connected to either a surge tank overflow fitting or a radiator fitting which connects to the Overflow bottle. As the cap is rotated OFF, pressure is relieved
18、thru this passage. Likewise, when cap pressure is exceeded, the pressure is relieved by lifting the UPPER VALVE off of its seal. Fluid (coolant or air) return occurs during cool down as negative pressure lifts the LOWER VALVE off its sealing surface, allowing fluid to be sucked from either the atmos
19、phere or the overflow bottle, back into the cooling system. 7. NOTES 7.1 Marginal Indicia A change bar (l) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. PREPARED BY THE SAE COOLING SYSTEMS STANDARDS COMMITTEE
