Chemical pumps are specially designed pumps for use in different industries, from common industrial applications to semiconductor, brewery and distillery, oil and gas, and many others. Owing to the nature of liquids handled by them, these pumps are made of materials capable of withstanding varying levels of abrasiveness, corrosiveness, and viscosity. In some cases, chemical pumps may also function as metering pumps, providing flow control and measurement features for applications where precision is required in terms of chemical volumes.
Selecting the Right Chemical Pump:
There are many different variables involved in selecting pumps for chemical application. Specialty software and pump handbooks can help select right pump specifications. Chemical compatibility data and MSDS are also used for this purpose. The first step is to understand the requirements of the specific application and properties of the chemical media to be handled by the pump. Based on this information, a pump with the required specifications to perform the task is chosen.
Main Criteria to Consider:
Mentioned below are some of the most important criteria for the selection of chemical pumps.
Materials of Construction: The chemical media to be pumped is one of the most important criteria to consider. The pump’s material of construction must be able to withstand the chemical media. With many chemicals, a major concern is corrosion. In addition highly corrosive acids such as nitric acid and sulphuric acid, alkaline solutions, chlorine, and water may also pose corrosion problems.
Metallic and non-metallic are the two major categories of pump materials. Metal pumps can be classified further into ferrous or nonferrous. Most of the metallic chemical pumps are made of corrosion resistant materials such as nickel alloy, stainless steel, or titanium. Non-metallic materials such as ceramics, plastic, glass, rubber, and some others are also used as pump materials for handling corrosive chemicals.
Pump Sizing and Performance Specifications:
When specifying a chemical pump, another important criterion is the selection of the proper pump size and performance specifications. Maximum discharge flow, maximum discharge pressure (head), discharge size, inlet size, and media temperature are the most important performance or size specifications.
If a pump is incorrectly sized, the fluid transfer system of the pump may experience operating problems. It is a common practice to use slightly oversized pumps. However, a greatly oversized pump will have higher operating costs, premature bearing failures, cavitation issues, operating temperature increases, and excessive vibration.
Types of Chemical Handling Pumps:
After material selection and sizing the pump based on its operating parameters, it is time to select the pump type. For chemical applications, you can choose from various pump types.
- Centrifugal Pumps: Extensively used because of the effectiveness and simplicity of their operation and design. These pumps move fluids through a system using one or more impellers.
- Rotary Pumps: Many different types of rotary pumps are used for chemical applications, including rotary vane pumps, screw pumps, gear pumps, and piston pumps. Compared to centrifugal pumps, these pumps are more efficient in handling low vapour pressure and high viscosity fluids.
- Diaphragm Pumps: These highly reliable positive displacement pumps make use of a reciprocating diaphragm for moving liquids, gases or gas-liquid mixtures.
- Regenerative Turbine Pumps: Also referred to as periphery or vortex pumps, these pumps move fluids using turbine-like impellers that have radially oriented teeth.
If you have any other questions related to selecting the right pump for any chemical application, please visit us at Tru-Flo Pumps.