Chemical air pumps are a popular choice when pumping chemicals or acids given their leak-free operation and diverse range of materials of construction. However, before selecting or purchasing a chemical pump, Global Pump suggests understanding the characteristics of your liquid and whether the chemical air pump selected is indeed suitable.
In this blog, we’ll discuss the types of chemical air pumps and their common applications to assist in your selection process.
What is a chemical air pump?
Chemical air pumps are most often air operated diaphragm pumps (AOD), or pumps that are driven by an air-motor.
AOD pumps, commonly referred to as pneumatic pumps, are a type of positive displacement pump. These pumps are driven by compressed air rather than an electric motor, which allows them to safely transfer and pump dangerous, flammable (as no sparks are present) or corrosive chemicals.
These pumps are designed with two chambers, each with their own inlet check valve, outlet check valve and diaphragm - which is why they are sometimes referred to as double diaphragm pumps. Back and forth movements shift the air supply from one chamber to the other. As the diaphragm moves back into the opposite chamber, fluid is forced out and the other chamber begins to fill. When the diaphragm moves back into the opposite chamber, the fluid is forced out. This is the motion that creates the pumping action.
To learn more about how AOD pumps work, check out this handy video.
What makes a chemical air pump a safe option for harsh applications?
Chemical air pumps are a popular choice for a wide range of reasons, including but not limited to:
- Safe and clean operation: Chemical air pumps have no motor, packing or seals, so they are less prone to leaking fluid compared to typical chemical centrifugal pumps. They are instead driven through compressed air. Therefore, as a solution for volatile, corrosive dangerous liquids that may cause harm, chemical air pumps are a suitable option. These pumps are a popular choice where mains power is not available, or where it is not safe to have electricity supply.
- Dry running capabilities: Unlike alternative chemical pumps, air operated diaphragm pumps are capable of running dry or against a closed discharge, without causing damage. This particular quality makes these chemical air pumps suitable for applications where pumps are often ‘fitted and forgotten’ about.
- Self-priming: AOD pumps are self-priming and have solid suction capabilities without the need for any manual lubrication. In applications where the suction conditions are difficult, like chemical drums or containers, chemical air pumps are a suitable option.
- Flexible performance: Air operated diaphragm pumps are versatile in performance, and are capable of meeting the exat flow rate or pressure requirements. Besides output, the wide range of materials of construction ensure suitability for a variety of fluids ranging in viscosity.
Chemical air pumps offer safe, efficient pumping for the harshest of chemicals - whether they be corrosive, explosive or highly flammable. Many AOD pumps are available with ATEX certification, as well as materials of construction that guarantee the integrity of your site and operators.
When selecting the materials of construction for your chemical air pump, Global Pumps suggest utilising a chemical compatibility chart. Based on the chemical you are pumping, the chart will reveal the most suitable materials for construction. You can use Global Pumps’ chemical compatibility chart here.
There are a variety of materials of construction available for chemical air pumps, including:
- Polypropylene - wide range of chemical compatibility, general purpose and resistant to high temperatures
- Conductive polypropylene - electrically conductive polypropylene
- PVDF -polyvinylidene fluoride or polyvinylidene difluoride is a highly non-reactive thermoplastic fluoropolymer produced by the polymerisation of vinylidene difluoride.
- Acetal - compatible with a variety of solvent applications, as well as resistant to abrasive media. This option is conductive for ATEX requirements.
- Aluminium - commonly used in general purpose applications, solvent-based coatings and inks and resistant only to mild chemicals.
- Cast iron - highly abrasive resistant, commonly found in paper, waste water industry and mining
- Stainless steel 316 - resistant to a wide range of acids, bases and solvents and can handle hydrocarbons and has good resistance to abrasive media as well.
Common applications for chemical air pumps
AOD pumps are found in a variety of chemical applications, including tasks that involve the following liquids:
- Acids and chemicals
- Oils and hydrocarbons
- Drum and container transfer
- Acid bath circulation
- Flammable liquid transfer
- CIP chemicals
- Drum cleaning
- General transfer
Besides the chemical industry, chemical air pumps can be used in mining, general and industry manufacturing applications where dangerous fluids may require transfer.
Want to learn more about chemical air pumps?
If you’re searching for a safe, effective chemical pump, get in touch with Global Pumps. Our team of experts have worked with leading chemical manufacturers and industries that utilise chemicals, to find safe, appropriate pumps for a wide range of applications. Contact our team to discuss your requirements!