Process pumps come in many variations: centrifugal, positive displacement, reciprocating, and rotary screw. There are also API or ANSI pumps.
This article covers not only the basics of different pump technologies but also gives a thorough explanation of reciprocating process pumps.
In general, when industrial customers look for a process pump, they are accustomed to sourcing centrifugal pumps. This is because centrifugal pumps represent over 90% of the global pumping market. The rest of the market is covered by positive displacement pump technology, including rotary pumps (gear, vane, lobe, etc.) or reciprocating pumps.
A centrifugal pump uses centrifugal force to pump fluids. This device is designed to move fluid by means of the transfer of rotational energy from one or more driven rotors, called impellers. Fluid enters the impeller and is cast out by centrifugal force along the impeller's circumference through the vane tips.
Mechanical power is generally supplied by an electric motor. Centrifugal pumps can have efficiencies as low as 40-50 percent on low-flow/high-head service.
Positive displacement pumps (PDP) are a type of pump that captures a moving fluid in a cavity and then discharges a fixed amount of it via mechanical pressure. The displacement of fluid takes place using a plunger, piston, diaphragm, depending on the design. Some of these pumps have an expanding cavity at the suction side and a decreasing cavity at the discharge side. The liquid is sucked at the inlet side when the cavity expands and discharges when the cavity decreases.
In general, a reciprocating pump has a higher efficiency than a centrifugal pump. Reciprocating pumps operate in low-flow and high discharge pressure environments. Milton Roy’s reciprocating pumps can handle flow rates from 0.09 liters per hour to 48 cubic meters per hour, and discharge pressures of up to 1,034 bar (15,000 psi).
Milton Roy offers two different technologies of liquid ends in reciprocating pumps: packed plunger and diaphragm type.
The main difference between centrifugal pumps and reciprocating pumps is that centrifugal pumps work with a low medium pressure head. By contrast, reciprocating pumps work with high medium pressure heads.
Chart: Reciprocating pump vs Centrifugal pump
The Primeroy series with variable eccentric drive features a small footprint, and ensures durability and optimum performance
When choosing a pump, you have to take into consideration the following:
The following table helps you select between a reciprocating diaphragm pump and a centrifugal pump.
Note that the list of selection criteria is not exhaustive.
There are two main types of process pumps: centrifugal pumps and reciprocating pumps. Both are used in oil and gas processes, refineries, the petrochemical industry, and chemical processes.
The technologies associated with process pumps are generally designed for handling any kind of fluids, but also aggressive chemical fluids.
API stands for the American Petroleum Institute which is the largest U.S. trade association for the oil and natural gas industries. It focuses on developing petroleum and petrochemical equipment and operating standards including all pump technologies.
The API has developed over 700 standards to improve safety, environmental protection, and sustainability in the oil and gas industry. These standards are adopted by many countries around the world.
Milton Roy offers a comprehensive pump range which fully complies to API 674 and API 675 standard.
The major advantages of API 675 pumps are:
The API standard is accredited by the American National Standards Institute (ANSI)
The ANSI standard provides for dimensional interchangeability of pumps from one pump manufacturer to another.
ANSI pumps provide generally reliable service across a wide range of applications. These pumps are often used to transfer and process fluids in various industrial settings. This includes chemical plants, refineries, pulp and paper mills, and wastewater treatment plants.
API pumps are more robust and are designed for heavy duty, higher pressure, and temperature applications.
Milton Roy offers a large range of API 674 and API 675 pumps with ANSI connection. They are suitable for all processes in the oil and gas, chemical and other heavy duty industries.
Milton Roy pumps comply with the following specifications:
Milton Roy has over 85 years of experience in industrial processes. We have developed a large range of options and features to cover the most critical applications such as: