Without risk of contamination, oil-free swing-piston NPK25 pumps transfer, evacuate, or compress air or inert gas. Compact micro pump and midsize version are offered, both with pressure or vacuum capability. Depending on type, flow ranges include 3.3, 9.0, 18, 25, 50, and 78 lpm with vacuum to 27.6 Hg and pressures to 100 psig. Cylinder-to-wall sealing lip minimizes frictional loss and extends life. Operable in any position, all versions can be supplied with ac motors, or brush or brushless dc motors. Brushless types offer longer service life along with fine speed control. Standard versions can be customized for specific needs.