This recommended practice establishes equipment and procedures for testing spark arresters used on medium size@ single position internal combustion engines@ normally used in transportable@ stationary@ and vehicular applications@ such as highway trucks@ agricultural tractors@ industrial tractors@ and other highway equipment. This recommended practice provides two uniform methods of testing (laboratory testing and engine testing) which may be used by spark arrester manufacturers@ governmental bodies@ and engine spark arrester users. Under the present state-of-the-art and under normal operating conditions@ taking into account the speed of the engine and exhaust flow rate@ a park arrester having an efficiency of 80% as determined by this procedure is considered adequate for most conditions and areas. Arresters meeting this standard should not be expected to arrest sparks adequately when titled more than 45 deg from their normal operating position. This procedure recommends testing spark arresters@ expect turbochargers3@ at flows causing back pressures up to 2 in. Hg (6.8 kPa). Should spark arrester applications be considered where back pressure above 2 in. Hg (6.8 kPa) are developed@ it is essential that additional testing be completed at the higher flow rate necessary to develop the actual maximum back pressure. Purpose-The purpose of this SAE Recommended Practice is to provide a standard method of testing to evaluate spark arresters as applied to compression ignition or spark ignition internal combustion engines. It is applicable to both turbocharged1 and nonturbocharged engines. It is not intended to establish the performance level2 required for adequate fire protection@ nor does it cover applications requiring flame arresting@ exhaust gas cooling@ or isolation from explosive gases. SAE J335 (September@ 1976) J342 (June@ 1968)@ and J350 (August@ 1972) have been established to cover most sizes and types of engines and engines applications. Arresters tested under this procedure should not be used above their rated flow unless found to be adequately efficient at the intended use level. 1Turbochargers are generally very effective spark arresters. 2When required performance levels are established@ consideration should be given to the area in which the engine is operating. For example@ in areas where daytime relative humidity of the atmosphere is below 30% for relatively along periods of time and there is considerable combustible material adjacent to the engine@ the best spark arrester should be utilized. In areas of high humidity and little or no combustible material@ spark arresters of lower ratings could be employed. 3Back pressure is not a meaningful limit to a turbocharged engine.
SAE J350-1972 history
2020SAE J350-2020 Spark Arrester Test Procedure for Medium Size Engines
0000 SAE J350-199101
1991SAE J350-1991 Spark Arrester Test Procedure for Medium Size Engines
1988SAE J350-1988 Spark Arrester Test Procedure for Medium Size Engines
1980SAE J350-1980 SPARK ARRESTER TEST PROCEDURE FOR MEDIUM SIZE ENGINES
1972SAE J350-1972 Spark Arrester Test Procedure for Medium Size Engines