Oil-lubricated pumps use oil for sealing, lubrication and cooling. They reach lower ultimate pressure and cost less to buy, but need regular oil changes and protection against oil backstreaming. Oil-free pumps avoid oil contamination and need less maintenance, which suits food, medical and electronics applications, although ultimate pressure and efficiency are usually lower than an equivalent oil-lubricated pump.
Choose oil-lubricated rotary vane pumps when a trace of oil vapour is acceptable and lower pressure matters; choose oil-free or dry pumps when cleanliness is a hard requirement.
