D39489-BA-PM-EN.pdf - 第39页

39 D39489 | Date 12/2019 Diaphragm pump PJ25481 - 950.50.1 8 Servicing Translation of origina l Installat ion Instructions , english , KNF 125530 - 31 6634 06/18 27 Final steps 1. Reconnect suctio n and pres sure line on…

D39489 | Date 12/2019

Servicing Diaphragm pump PJ25481-950.50.18

26 Translation of original Installation Instructions, english, KNF 125530-316634 06/18

2. Remove from the intermediate plates (Fig. 8/6) the valve plates

(16) and (17) and the O-rings (5) and (18).

3. Manually screw the ne diaphragms (Fig. 9/7) into the connect-

ing rod’s threads and tighten to hand tightness.

Before you finally tighten the diaphragms, you are recom-

mended to move the diaphragm to the upper dead center.

4. Insert the new valve plates (Fig. 8/16) and (17) and the new O-

rings (5) and (18) into the intermediate plates (6).

The upper and lower sides of the valve plates are identical.

When inserting the O-rings, make sure that they are the correct

size and color (head 4: black O

-rings).

Install intermediate plates and head cover

1. Place head plate (Fig. 8/4) onto the intermediate plates (6), ob-

serving the felt-tip pen marks (Fig. 6/M).

2. With your hands, carefully and lightly tighten the head plate’s

head screw (Fig. 8/2) on all four heads (tightening torque:

60 Ncm).

Refer to for arrangement and alignment of disk springs and the

screw’s washer.

When inserting the O-rings, make sure that they are the correct

size and color (head 4: black O

-rings).

3. Place three O-rings (Fig. 7/19) into each of the head connec-

tion holes.

4. Press together heads 1 and 2 (Fig. 6/I and II) and heads 3 and

4 (III and IIII).

5. Place heads 1 and 2 and heads 3 and 4 onto the compressor

housing; alternately tighten attachment screws (Fig. 4/3) to

hand-tightness (tightening torque: 3.5 Nm).

6. Insert O-rings (Fig. 6/12) and flat seals (13) into the head con-

nection receiver.

7. Reinstall the head connections:

To do this, manually tighten the head connections’ attachment

screws (Fig. 5/10 and 15).

8. Reinstall the head connection cover (8):

To do this, manually tighten the head connection cover’s at-

tachment screws (9).

9. Reinstall the head covers (Fig. 4/20):

To do this, manually tighten the eight attachment screws (1).

10. Properly dispose of the old diaphragms, valve plates, and O-

rings.

Fig. 10: Aligning the

disk spring

D39489 | Date 12/2019

Diaphragm pump PJ25481-950.50.18 Servicing

Translation of original Installation Instructions, english, KNF 125530-316634 06/18 27

Final steps

1. Reconnect suction and pressure line on the pump.

2. Reconnect the pump to the mains.

If you have any questions about servicing, call your KNF technical

adviser (contact data: see www.knf.com).

D39489 | Date 12/2019

Troubleshooting Diaphragm pump PJ25481-950.50.18

28 Translation of original Installation Instructions, english, KNF 125530-316634 06/18

9. Troubleshooting

DANGER

Extreme danger from electrical shock!



Disconnect the pump power supply before work-

ing on the pump.



Make sure the pump is de-energized and se-

cure.

 Check the pump (see Tab. 12 and Tab. 13).

Pump does not transfer

Cause

Fault remedy

Pump not connected to the

mains.

 Connect pump to the mains.

No voltage in the mains.

 Check room fuse and switch on if necessary.

 The motor board’s overcur-

rent protection circuit has

activated.

 Maximum temperature of

motor board is exceeded.

 Maximum blocking time of

the rotor is exceeded.

 Separate pump from the mains.

 Determine and remove the cause of the overcurrent (for ex-

ample: improper pressure, liquid in the pump heads).

The pump must be separated from the mains for several

seconds before the electronics will permit restarting.

Connections or hoses are

blocked.



Check hoses and connections.

 Remove blockage.

External valve is closed or filter

is clogged.



Check external valves and filters.

Condensate has collected in the

pump head.

 Detach the condensate source from the pump.

 Flush the pump (see Chapter 8.2.1).

Diaphragm or valve plates are

worn.



Replace diaphragm and valve plates (see Chapter 8.3).

Tab. 12

Flow rate, pressure or vacuum too low

The pump does not achieve the output specified in the Technical data or the data sheet.

Cause

Fault remedy

Condensate has collected in the

pump head.



Detach the condensate source from the pump.

 Flush the pump (see Chapter 8.2.1).

Presence of positive pressure

on the pressure side with simul-

taneous vacuum or positive

pressure on the suction side.

 Change the pressure conditions.

Cross-section of pneumatic

hoses or connectors too narrow

or restricted.

 Disconnect the pump from system and determine output

values.

 Remove restriction (e.g. valve) if necessary.

 If applicable, use larger-diameter hoses or connectors.

Leaks in connections, hoses or

pump head.

 Make sure the hoses and connections.

 Remove any parts or particles causing blockages.

Pump head components are

soiled.

 Clean head components.