techtipsTechnical Support

Our trained Sales & Technical Support Staff is available to assist you in making the right choices for all of your pumping applications. Have more questions? Contact FMI for a direct connection to Fluid Metering's application experts.




Technical Tips

Q. What is the recommended FMI "Q" Pump Mounting for maximum performance?



Q. What is the recommended FMI "H" Pump Mounting for maximum performance?


A. The recommended FMI "STH, RH OR STQ PUMP DRIVE MODULES" Pump Mounting for maximum pump performance, mount the pump with motor at 12 o'clock and pump head at 6 o'clock position. This orientation will allow air bubbles that enter the pumping chamber to directly exit thru buoyant assist. Discharge lines should be inclined upward from pump head.


Q. What is the general guideline for pumping high viscosity fluids?

A. FMI pumps are considered viscosity independent indicating that most high viscosity fluids can be dispensed or pumped at low flow rates and low speeds. Free flowing fluids are easier to pump than non-flowing fluids.
Viscous fluids up to 500 centipoise can usually be pumped by most FMI Pump Drives and Pump Heads. In most cases no additional steps are required to achieve good performance.

Viscous fluids above 500 centipoise may require one or more of the following steps to achieve better results:

1. The slower the RPM the better. Try to keep RPM below 400. Use stainless cylinder case material (CSC, CSC-WT, CSC-TC, CSY, SSY)

2. Set Pump Head closest to 100% of Pump Head Module flow rate. A longer piston stroke is better than a short piston stroke.

3. Use the largest ID suction line possible.

4. Increasing tubing ID size on discharge line can help reduce back pressure buildup.

5. Reduce viscosity if possible - try Heating the fluid (use CSC-WT pump head) or if applicable dilute the fluid using suitable thinner. Check temperature limits of Pump Head Module in catalog.

6. Improve flow to pump -Free flowing fluids should be gravity fed.

Non-flowing fluids may require the use of a pressure pot to get fluid into pump head. Do not over pressure the suction line. Use minimum pressure necessary to help deliver the fluid into the pump head.

7. Dispensing small drops of high viscosity fluids may require physically moving the dispenser head to the point of delivery and making contact at that point. This will help prevent the drop from remaining on the dispenser tip.

8. High viscosity fluids may require modified ceramic Piston-Liner sets. Consult factory.

Note – The molecular chemical composition of certain fluids may pose a pumping challenge even though a similar viscous fluid can be easily pumped. Typically polymers in the Cationic family may pose such difficulties.

Q. What is the isolation gland "W" option setup?

A. In a special modification of certain FMI Pump Head Modules (designated by suffix "W" or "WT"), a pair of extra ports provide a barrier gland of liquid, gas, steam or whatever fluid required to isolate the pumped fluid from the seal area and atmosphere. Slurries, particulates, crystal formers, and anaerobics are easily handled at temperatures and pressures unattainable before. The Isolation gland option is available for Q1, Q2,Q3, CKC, CKC-LF, & CSC Pump Head Modules.