SPECIFYING THE PROPER chemical metering pump for an application can be difficult. However, the process can be simplified by acquiring all application parameters. It’s important to take into account factors such as the fluid to be pumped, the output volume required, and the pressure which the pump will be working against in the system.
Once all parameters are taken into consideration, the information will serve to guide the engineer or end-user in selecting the best pump option to ensure optimal performance.
As compared to diaphragm-style metering pumps, peristaltic units are the newer technology. However, in recent years peristaltic metering pumps have been widely accepted as the preferred technology in many applications, including municipal drinking water and wastewater treatment, food and beverage processing, and commercial swimming pool and aquatics water sanitation, as well as many others.
These types of applications use chemicals which off-gas and calcify. When diaphragm pumps are used, this can cause vapor locking as well as clogged valves. Peristaltic pumps are not affected by gas, air bubbles, or particulates. Peristaltic technology allows the bubbles and particles to simply be moved through the system.
Also to be considered, peristaltic units do not require regular maintenance other than pump tube replacement due to wear. Diaphragm pumps, on the other hand, require ongoing maintenance because the valves must be regularly cleaned.
The estimated life of the peristaltic pump tube can be determined when all application parameters are known. This allows operators to implement a regular maintenance schedule which can increase efficiency and be cost-effective.
Diaphragm pumps typically require weekly maintenance whereas a peristaltic tube could be replaced as infrequently as once per year, depending on the system conditions. This leads to minimal downtime at the plant and allows an operator’s time to be spent on other equipment needs and day-to-day operations, thus creating an indirect cost savings to the user or water treatment plant.
An additional advantage of peristaltic pumps over diaphragm pumps is that they perform well against limited pressure. They will not lose output rate versus pressure, whereas diaphragm units do require the use of a backpressure valve and pulsation dampener.
The smooth feed of peristaltic metering pumps also eliminates the need for these ancillary items, leading to further cost savings.
While peristaltic pumps offer many advantages, one disadvantage can be pumping against high pressures. As the pressure increases in a system, the pump tube life decreases. This is due to the increase in pressure which increases the force on the walls of the rubber tubing.
Both types of pumps have their advantages. One of the most important aspects in specifying the correct pump is, once again, acquiring all details regarding the application prior to specifying or purchasing a unit. This information will help ensure that the unit chosen provides the best and most efficient level of performance.
In conclusion, finding the pump that is the right fit for your application will save time, money, and energy.
