Highest reliability air valves for no stall operation. No Lube air valves reduce routine maintenance. High flow design with complete range of diaphragm options. Rugged construction for long, trouble free perfomance. Ideal for spill response and all types of transfer applications. Model 1040 is a 1", 1590 is 1.5" double diaphragm pump for similar applications. See Technical Data for more information.