Positive displacement blowers are high pressure and low volume devices. It delivers generally fixed volume with varying inlet and/or discharge pressures. The throughput of a centrifugal blower can vary significantly with only minor changes in inlet or discharge pressure. Positive displacement blowers are available with gas-tight mechanical seals, generally avoiding the need for seal purge gas. The high-pressure air supplied by positive displacement blowers is used for applications such as injection type pneumatic conveying systems and reverse-flow cleaning of filters.
Positive displacement compressors can be found in ranges from fractional to very high horsepower. They work by filling an air chamber with air and then reducing the chamber's volume (reciprocating, rotary screw and rotary sliding vane are all positive displacement compressors). They offer smooth, continuous flow with no reciprocating motion or pulsation. For processing dirty, polymer-forming or corrosive gases, our compressor offers us the reliability of centrifugal compressors with the surge-free performance of reciprocating compressors.
Positive Displacement Flowmeters are instruments that divide specific and known amount of flow stream into parts and count them for an indication of totalized flow. Several ingenious method have been devised to accomplish this operation. They are commonly used for customer metering. It is used to measure liquid products. These meters are very reliable and accurate for low flow rates because they measure the exact quantity of water passing through them.