[6]
No remodeling
Never try to remodel the pump. This may cause a serious accident or damage.
[7]
Limitation to disassembly or repair
Users are allowed to disassemble and repair the pump to the degree of the given description in "Disassembly
and Assembly" in this manual.
[8]
No dry running operation
Dry operation of the pump (pump operation without liquid inside) may cause damage to the pump internally.
Never operate the pump dry. In the case of MDF-L type, the sliding parts are self-lubricated and self-cooled. If
the pump is operated dry or with the suction-side valve closed, damage may result.
* Countermeasures to be taken in case of dry operation
1. Turn off the power switch of the pump immediately and leave the pump as it is for more than 1 hour.
2. Prime the pump and fill the pump with liquid.
(Note that the pump should be supplied with liquid after leaving the pump empty for more than 1 hour.
Sudden supply of liquid may cause a crack in a part due to quenching effects.)
[9]
Dry operation compatible type pump
The dry running operation compatible type pump (with D at the end of the model identification) can endure
continuous dry running operation of not longer than 1 hour. Longer dry running operations, if repeated
frequently, may result in wear of the sliding parts which rapidly affects the normal functioning of the inner part
of the pump. The pump is designed so as not to develop cracks as a result of sudden cooling down with liquid
immediately after dry operation. However, it is recommended that the pump be left as it is for about 20 minutes
before running it with liquid.
* Pumps with E at the end of the model identification or without any symbol cannot endure dry running
operation.
[10]
Points to be noted when starting and stopping pump
Pay close attention to the following points to avoid water hammer action when starting and stopping pump
operation. When the discharge-side piping is very long, extra attention is required.
(1) When starting the pump, first prime it. Then, close the discharge valve completely and turn on the power
switch. After starting up the pump, open the discharge valve gradually and set it to the desired operation
level.
(2) When stopping the pump, first close the discharge valve slowly. Turn off the power switch only after
completely closing the discharge valve.
In this procedure, never try to stop the pump quickly using a solenoid
valve, etc. Quick closure may cause water hammer action, and the
excessive pressure will destroy the pump.
- 17 -
Caution
