Priming The Pump
The pump must be primed before starting. This means that the pump case and the intake
piping must be filled with water, with no air pockets. If the pump is higher than the water
source, the system must have a foot valve (see above) and a means to easily fill the pump
and the intake pipe with water. This must be easy to do without removing pipe fittings. It is
common practice to install a tee fitting at the pump outlet, pointing upward, with a ball valve.
If there is to be a check valve in the outlet pipe, then place this tee before the check valve.
Pour water into the priming valve until air stops rising out. If the pump does not start
immediately, stop and reprime it. If the pump is starting against pressure, it will help to keep
the priming valve open until flow is established. In difficult cases, a small hand pump can be
used to prime the pump. Hand pumps are available from marine suppliers.
Dry Run Prevention
The shaft seal in the pump will be quickly destroyed if the pump runs dry. A damaged seal
will cause leakage of water around the pump shaft. If it is possible for the water source to be
depleted, you may wish to install a float switch to disconnect the power if the water level
falls too low. The float switch must be rated to carry the DC voltage and current for your
application. Float switches are available from your Dankoff dealer.
Preventing Tank Overflow
A float valve can be used at the pump outlet to stop the flow upon filling a tank. However, if
the flow is 100% stopped, there is danger that the water in the pump can get very hot from
fluid friction and cause damage. A float valve installation should have an “imperfection”
established so that the flow is never completely stopped. An better method is to install a
float switch in the tank. The float switch must be rated to carry the DC voltage and current for
your application. Float switches are available from your Dankoff dealer.
Maintenance
Shaft Seal: Seals may last for a few years, but if the water contains abrasive silt, the seals
will wear faster. Seals will be quickly ruined if the pump runs dry. You can purchase spare
seals from your Dankoff dealer. Seals MUST be installed correctly. The smooth white
ceramic face must face outward, away from the motor. The part with the spring presses over
the shaft. The all-black end must contact the white ceramic face. The metal and rubber end
faces away from the motor.
Seal and Gasket Kits
If last digit of the pump model number is 1, 2, 3, or 4 — order Dankoff Solar item #37690
If last digit of the pump model number is 5 or 6 — order Dankoff Solar item #37691
Seal and Gasket Kits for High Temperature pumps
If last digit of the pump model number is 1, 2, 3, or 4 — order Dankoff Solar item #37695
If last digit of the pump model number is 5 or 6 — order Dankoff Solar item #37696
The seal is an industry-standard pump seal for 5/8” shaft. In case of emergency, you may be
able to obtain one from a local pump supplier or electrical repair shop. If the paper pump
gasket is damaged, a new one can be cut from thick paper. Manila file folders works fine.
