Adjustable, air-operated PurgeX with 1/8 in. piston completely purges all entrained air and impurities with each stroke. Maximum output is 0.0012 cu in./0.00066 oz. Each clockwise turn of integral calibration ring reduces output by 0.00026 cu in./0.00014 oz. High output pressures can be achieved due to 25:1 ratio from air inlet to liquid outlet. Pressures of 3,000 psi output can be achieved with 120 psi air. Injector pump is aluminum with brass, steel, and SS components.