Model AT-1000. A specially constructed and calibrated valve manufactured solely for this test. The valve has two open positions, a wide open position for flushing and a small preset flow position for testing. ASTM D-2713-76 and GPA Standard 2140-80. Furnished with carrying case but without needed stopwatch, sample cylinder having minimum capacity of 3 gal. and clean, dry cloth. It is recommended that the unit be washed in petroleum ether or mineral spirits and dried with air or nitrogen. Avoid contamination with dirt or grease while handling the filter element. If the valve is dropped or damaged in any manner, it should be returned for reconditioning and recalibration.