In the sanitary process industry we have specified and applied thousands of sanitary pumps into a huge variety of high purity applications in the food, beverage and biopharmaceutical industries. To identify the best sanitary pump for the application we rely on a number of analytical tools to assist in the process, including several pump sizing programs, pressure drop calculation software, manufacturers data as well as a lot of tribal knowledge we have developed over the years.
A major key in selecting the proper pump is to get as much application data as possible from the client. Some clients have a vast knowledge of their product and application, others are much more limited, or sometimes not known at the time of request. To assist in this process we have published a “Pump Application Datasheet” we request customers fill out to the best of their ability. In this posting we thought we would review the data we ask for on the datasheet, what it means and why it is important.
- Application Description: Understanding the application gives us a much better feel for what type of pump will do the job. We’re trying to figure out what you want to accomplish. Case in point: An application for 20gpm @ 30PSI for a liquid transfer from one tank to another may use a very different pump than one at the same flow rate and pressure that is metering a fluid in a filling application.
- Fluid Description: Different fluids will require different seal and elastomers. Different fluids also have different vapor pressures that can affect the suction conditions of a pump application.
- Viscosity: Determining the viscosity of the fluid is critical. Higher viscosity products won’t work with a centrifugal pump. Extremely high viscosity fluids can create suction issues that need to be address on positive displacement pump applications. Viscosity is also important in calculating friction loss.
- Density/Specific Gravity: This can affect centrifugal pump sizing criteria as well as horsepower requirements
- Temperature: Both the process and cleaning temperatures are very important. In a sanitary rotary PD pump such and a Waukesha Universal pump, higher temperatures may require the pump to have undersized rotors to prevent them from contacting the casing and front cover as the wetted parts of the pump expand under heat. Temperatures can be a factor in proper elastomer selection. Also, elevated temperatures affect the vapor pressure of a liquid and consequently the net positive suction head available.
- Flow Rate: This one is pretty obvious
- Discharge Pressure: This is critical in sizing centrifugal pumps in particular. Proper sizing cannot be completed without a discharge pressure requirement. Discharge pressure can also affect PD pumps in that all PD pumps have a maximum pressure rating. The pressure also affects horsepower requirements. If you don’t know you pressure requirement we will help you determine that using the discharge conditions listed further below on the datasheet.
- Is the Product Sticky or Abrasive? This directly affects the mechanical seal material selection and whether or not a seal flush will be required.
- Suction Conditions: A general overview of the suction piping can help to specify a pump that meets the net suction pressure. Are you coming out of a tank? How high off of the ground is the tank? Are there any suction flow restrictions?
- Discharge Conditions: If you don’t know your discharge pressure requirements, give us the discharge conditions, i.e. a brief description of the process, the piping sizes, lengths and elevations. We can use that data, along with the flow rate and viscosity information to generate your pressure requirements. We have developed in house software that will do these calculations quickly and accurately.
- Seal Requirements: If you know you seal requirements, i.e. single or double mechanical seal, seal materials and elastomers, tell us here. If you need a recommendation we can do that using the fluid properties and temperatures on the upper part of the form.
- Motor Requirements: There are a lot of choices in motors (see our earlier blog on different ratings and enclosures for motors). This section allows you to specify your requirements. If are unsure, we will walk you through the process.
TAG, Centrifugal Pumps, Sanitary PD Rotary Pumps, Sanitary Pumps