Rotary Pumps and Its Fundamentals

Rotary pumps are normally driven by motors like belt-driven, geared motors, or electric motors. Sometimes it is also driven by steam turbines. In terms of economy, these pumps stand second after centrifugal pumps. Fluids that are entrained with gas or vapor consisting of liquids are handled by rotary pumps. They have the ability to flowing continuously with lower pulsation levels. When we say that these pumps are driven by electric motors, they are often operated at a constant speed with commonly recirculation method. Mechanical seal manufacturers in India, usually install permanent suction strainers to avoid damage of pumps by foreign materials. Any kind of plugged strainer will also damage the rotary pump. 

Suck and squeeze action is the operation of rotary pumps. They suck the fluid and squeeze it. The installation should not be in such a way that the piping, thermal expansion imposes strains in their casing and is damaged. Rotary pumps should be lubricated before starting as they are responsible and capable to handle quantities of vapor. Packing or mechanical seals should be monitored closely to avoid air in leakage. 

The most common rotary pumps include gear, single and multiple- screw. Typical applications for these pumps include viscous fluids. These pumps can deliver high-viscosity fluid with less efficiency compared to other types of pumps. Rotary pumps are considered to be the most economical selection when the viscosities fluids vary from LPG to very viscous greases with >2200 cSt (10,000 SSU). Reciprocating pumps as we discussed above can handle more high viscosity equally like rotary pumps. The only difference between the two is that reciprocated pumps become expensive as they need a larger size to handle the fluids and so these are not economical. 

Lubricating and hydraulic oils are used to circulate in rotary pumps in mechanical equipment to provide pressure which will clean the systems by filtering. The fluid which is then pumped will help lubricate the pump’s internal gears and bearings.  As these are pumped it is commonly used in vacuum services to pump gases and vapors. Oil separators are connected to excrete the oil from the gas. Mechanical seal manufacturers use either oil or water seal to obtain a limited vapor pressure of the sealing liquid. Nonpulsating flow is used for hydraulic operating systems and fuel oil systems where rotary pumps work well especially when high viscosity renders centrifugal pumps. 

Mechanical seal manufacturers in India provide pumps like electrical barrel pumps which are specially designed to transfer fluids such as acids and solvents. A drum pump is another name for barrel pumps, a portable pump to transfer liquids in a standard barrel size of 200 L to 220 L.