SAE J335:2020 pdf free

SAE J335:2020 pdf free.Multiposition Small Engine Exhaust System Fire lgnition Suppression
This SAE Recommended Practice establishes equipment and test procedures for determining the performance of spark arrester exhaust systems of multiposition small engines (<19 kW) used in portable applications, including hand-held,hand-guided, and backpack mounted devices. It is not applicable to spark arresters used in vehicles or stationary equipment.
Recommended performance criteria are given in Appendix A. These requirements are adequate for the severe fire hazard condition posed by heavy vegetative fuels. However, during periods of extreme fire danger, exhaust systems meeting this document may not give absolute protection against fires. Additional operational restrictions may be necessary during such periods.
Place the MSE power unit on a horizontal plane in the position which places the exhaust system nearest to that plane. In this position, identify three points where the power unit contacts the horizontal surface. This is the first contact plane. Using two existing contact points in the first plane, rotate the power unit until a third contact point has been identified. This is the second contact plane. Repeat this process until a total of three contact planes have been established. Additional planes may be tested using good engineering practice. The contact plane closest to the exhaust flow direction shall be used for determination of the hot spot for the exhaust gas temperature. If any test plane contacts the exhaust system surface, the exhaust surface temperature shall be measured at this contact point. Mark the contact point accordingly. (Refer to Figure 1 for chain saws, Figure 2 for brush cutters, Figure 3 for hand held blowers and Figure 4 for backpack blowers, Figure 5 for hedge trimmers,Figure 6 for Multi-Task tool, and Figure 7 for Cut-off machines)
Use narrow drafting-style tape and/or stiff, straight metal rods (3.0 mm or less in diameter) to connect the contact points in each plane, as shown in Figure 1. These shall be used to provide more accurate thermocouple probe alignment during the test.SAE J335 pdf free download.