All rotary pumps have rotating parts, which trap the fluid at the inlet (suction) port and force it through the discharge port into the system. Gears, screws, lobes and vanes are commonly used to move the fluid. Rotary pumps are positive displacement of the fixed displacement type. Rotary pumps are designed with very small clearances between rotating parts and stationary parts to minimize slippage from the discharge side back to the suction side. Rotary pumps are designed to operate at relatively moderate speeds. Operating at high speeds causes erosion and excessive wear, which results in increased clearances.
Positive displacement rotary pumps are pumps that move fluid using the principles of rotation. The vacuum created by the rotation of the pump captures and draws in the liquid. Rotary pumps are very efficient because they naturally remove air from the lines, eliminating the need to bleed the air from the lines manually.
A wide variety of rotary pumps are available in various model, pressure and size, capacity, design etc. These are used in a variety of applications like transferring and unloading fuel oil, diesel and other viscous products, developing pressure in hydraulic power pack and in many other applications. Some of them are designed and built to withstand continuos operations under various conditions. Rotary vane vacuum pump, rotary piston two stage pump, rotary vane pump, rotary lobe pump, rotary hand pump, rotary vacuum pump, rotary gear pump, direct driven rotary high vacuum pump, rotary oil pump, rotary piston pump vacuum, rotary barrel pump, rotary piston pump are some of the examples of rotary pumps.
They are widely used in cement industry, dyes and chemical industries, engineering industry, textile industry, drug and pharmaceutical industry, glass, tiles and ceramic industry, machine tools industry, paper and pulp industry, petrochemical plants, fertilizer industry, ship building industry, paint industry and in many other industrial sectors. Indeed a product, which fulfils all the pumping requirements of it's customer.
Diaphragm pump are positive displacement pumps that uses a combination of the reciprocating action of a rubber or teflon diaphragm and suitable non-return check valves to pump a fluid. Diaphragm pumps with teflon diaphragms, ball check valves, and hydraulic actuators are used to deliver precise volumes of chemical solutions at high pressures into industrial boilers or process vessels. Diaphragm pumps are low-shear pumps with good dry running characteristics. Diaphragm pumps can be used to make artificial hearts. Diaphragm pumps can be used to provide oil free air for medical, pharmaceutical and food related purposes.
Gear pumps use the meshing of gears to pump fluid by displacement. They are one of the most common types of pumps for hydraulic fluid power applications. Gear pumps however are also widely used in chemical installations to pump fluid with a certain viscosity. Gear pumps are fixed displacement, meaning gear pumps pump a constant amount of fluid for each revolution. Some gear pumps are designed to function as either a motor or pump.
