Maintenance and repair
en
Installation and operating instructions Wilo-Padus PRO
25
9.5.5
Oil change in sealing chamber
WARNING
Operating fluid under high pressure!
A pressure of
several bar can build up
in the motor! This pressure escapes when the
screw plugs are
opened
. If screw plugs are opened without due caution, they can be
ejected at high speed! To avoid injuries, observe the following instructions:
• Adhere to the prescribed sequence of work steps.
• Unscrew the screw plugs slowly, but never unscrew them completely. As soon
as the pressure escapes (audible whistling or hissing of air), stop turning the
screw plug any further!
• When the pressure has completely dissipated, fully unscrew the screw plugs.
• Wear closed safety goggles.
WARNING
Scalding from hot operating fluids!
Hot operating fluids can also spray out when pressure is released. This can result in
scalding! To avoid injuries, the following instructions must be observed:
• Allow the motor to cool down to the ambient temperature before opening the
screw plugs.
• Wear closed safety goggles or face protection and gloves.
1
Fig. 7: Sealing chamber: Oil change
1
Sealing chamber screw plugs
The pump has two screw plugs for the sealing chamber. The operating fluid is drained
through one screw plug. The other screw plug is used to aerate the sealing chamber.
‡
Protective equipment must be worn!
‡
Pump has been dismantled and cleaned (decontaminated if required).
1. Position the pump in a horizontal position on a firm surface. The screw plug should
face upwards.
WARNING! Risk of hands being crushed. Make sure that the pump
cannot fall over or slip!
2. Unscrew the screw plug slowly, but do not unscrew it completely.
WARN-
ING! Overpressure in the motor! Stop turning the screw plug further if hissing
or whistling is audible! Wait until the pressure has completely dissipated.
3. After the pressure has dissipated, completely unscrew the screw plug.
4. Position a suitable reservoir to collect the operating fluid.
5. Drain the operating fluid: rotate the pump until the opening points downwards.
Unscrew the second screw plug for aeration.
6. Check the operating fluid:
⇒ If there is a leak in the mechanical seal, small amounts of water can enter the
sealing chamber. This turns the oil milky/cloudy. If the ratio of oil to water is
smaller than 2:1, the mechanical seal may be damaged. Change the oil and
check again after 4 weeks. If water is in the oil again on the second check,
contact customer service!
⇒ Notify customer service if the operating fluid contains metal swarf!
7. Clean the aeration screw plug, replace the seal ring and screw the screw plug in
again.
Max. tightening torque: 8 Nm (5.9 ft·lb)!
8. Pour in operating fluid: Rotate the pump until the opening points upwards. Pour
the operating fluid into the opening.
⇒ Comply with the specifications for the operating fluid type and quantity!
9. Clean the screw plug, replace the seal ring and screw it back in.
Max. tightening
torque: 8 Nm (5.9 ft·lb)!
