DAVE’S CORNER: DRY RUNNING DIAPHRAGM PUMPS

All Yamada diaphragms are rated to 100 PSI maximum and in many applications are run at pressures greater than 100 PSI without incurring diaphragm damage. Even though you can run diaphragm pumps dry, it is something that you should avoid for several reasons:

• Every cycle a pump runs dry is one less cycle it will run to perform work.
• Running a PTFE diaphragm dry can cause premature failure. We rate it to 100 PSI air pressure if there is liquid in the pumping chambers to help counterbalance the high air pressure.
• Why pay for compressed air? That is a waste of money.

If using PTFE diaphragms, and there is no liquid present, we recommend limiting air pressure to 70 PSI. To help prevent damage to the PTFE diaphragms you may want to consider a Liquid Level Controller (LLC-1 through LLC-4) or a device to shut the pump off, such as a DRD-100, during dry run times.