SAE J151:2020 pdf free

SAE J151:2020 pdf free.Pressure Relief for Cooling System
This document applies to passenger cars, multipurpose passenger vehicles, trucks, chassis cabs, buses, construction vehicles, and to equipment produced for motor vehicles manufactured after the effective date of this document.
Pressure relief which is actuated without operator action for the purpose of limiting peak pressures in the cooling system should be accomplished 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.
Pressure release mechanism incorporated in the cap and/or fller neck shall conform to one of the following: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.
Either mechanical stop that prevents cap removal by rotation only, requiring the cap to be moved axially and further rotated, for removal.
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.
If pressure relief is accomplished through other than cap rotation, a means shall be provided to prevent removal of the cap before the pressure relief is actuated.
The area between the 2 O-Rings is open to the atmosphere. This passage may be connected to either a surge tank overflow ftting or a radiator itting which connects to the Overflow bottle. As the cap is rotated OFF, pressure is relieved thruthis 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 atmosphere or the overflow bottle, back into the cooling system.
A change bar (1) 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.SAE J151 pdf free download.