Did you know that the anticipated temperature of the medium being pumped and the environment the pump will be in, are two critical components in the pump selection process? Understanding these will ensure you select appropriate materials of construction and most importantly, the correct pump.
In this blog, our team discuss how critical temperature is during the selection process - and how ignoring this can cause significant issues down the track.
Temperature refers to the measure of the heat present in a gas, liquid or solid. In pump selection, we consider both the atmospheric temperature and the pumped medium’s temperature.
Temperature and pressure
Temperature not only influences the operational stability and efficiency, but it impacts the system’s pressures. As a gas’ temperature approaches zero, it becomes a liquid. As temperature continues to rise, the gas’ pressure does so as well.
As different mediums build up pressure in distinct ways, a system must be specifically designed around the pumped medium’s characteristics. If this is not considered, and the pump selector is not aware of how gasses will respond to temperatures within the system, faults can occur costing the business time, money, and production.
Challenges with freezing temperatures
When pumps are left outside or are permanently outdoors and temperatures drop overnight, liquids within the pump can freeze. When these pumps are restarted, issues can arise - breaking or causing wear issues to parts. Therefore, heating jackets may be required to maintain a consistent temperature within the pump or insulation. Alternatively, pumps can be mounted on skids or on trolleys to allow operators to move these indoors.
How temperature can affect your pump
During the selection process, there are several key considerations. We outline these in a recent blog.
One of the most important to note is temperature. Temperature can affect your pump/s in the following way:
- Corrosion to materials of construction: If you are pumping certain chemicals, corrosion can occur depending on the temperature. Hot boiling liquid has more corrosive action against the materials than those at cooler temperatures. It is therefore important that you check the chemical compatibility at the temperature you will be pumping.
- Components of the pump: As the temperature rises, heat is transferred from gland packing through the shaft to the bearing. This causes a significant reduction in bearing life and may even seize the bearing. This only occurs if your pump is gland packed.
- Viscosity of the fluid: Liquids that are influenced by temperature can change viscosity during the pumping process. For example, honey when heated becomes runny, changing how it will be pumped. Therefore, understanding how temperature change's your products viscosity during pumping will ensure the correct pump is selected. Discover the importance of viscosity in the pump selection process in this blog.
- Expansion of parts: At high temperatures, metal parts can expand at different rates. This is particularly critical during the pump selection process and should influence what materials of construction you select.
- Preserving the heat or maintaining low temperature: In some instances, your application might require a certain temperature being maintained. This can be achieved by maintaining the flow conditions, or by utilising a heating jacket which allows you to maintain high temperatures. Alternatively, if you need to maintain a low temperature, proper insulation can be provided.
- It's important to note that if you have a flooded suction for your pump, you still need to consider the temperature and the vapour pressure of the fluid to ensure your pump has the correct NPSHa.
Want to learn more about the pump selection process? Particularly what to consider when selecting a new pumping system or when upgrading your current pumps? Get in touch with Global Pumps today!