M&C TechGroup N9 KP18 Operator's manual - Manual (Page 16)

16
Gas sampling and conditioning technology 6-1.2.1ME
14.2 CHANGING THE DIAPHRAGM TYPE N 3/5/9 KPE/KP18

Turn the fan to bring the structured diaphragm 9 to top dead centre.

Lift the edge of the diaphragm and gripping it on opposite sides unscrew it by turning anti-
clock-wise. Please take care that the diaphragm spacers 11 on the threaded portion of the
diaphragm do not fall into the housing.

Take the diaphragm spacer 11 off the threaded portion of the diaphragm and retain them.

Check that all parts are free from dirt and clean them if necessary.

Put the diaphragm spacer on the thread of the new diaphragm.

Turn the fan until the connecting rod 13 is at top dead centre.

Screw the diaphragm complete with diaphragm spacer into the connecting rod (clockwise)
and tighten it by hand.
14.3 CHANGING THE VALVE PLATES TYPE N 3/5/9 KPE/KP18

Separate the head plate 3 (N3/5 with metal frame) from intermediate plate 2.

Remove the valve plates 7 and sealing rings 8 from the intermediate plate.

Check that the valve seats in the head plate and intermediate plate are clean. If scratches,
distortion or corrosion are evident on these parts they should be replaced.

Lay the new valve discs in the recesses in the intermediate plate. The valve plates for suc-
tion and pressure sides are identical as are upper and lower sides of the plates.

Check that the valve plates are not deformed by moving them gently.

Lay the sealing rings on the intermediate plate.
N O T E !
Valve plate and sealing ring for pump type N9 are connected to one
spare part since 02/2007.
14.4 REFITTING THE PUMP HEADS TYPE N 3/5/9 KPE/KP18

Turn the fan to bring the diaphragm to top dead centre.

Place the intermediate plate 2, with valve plates 7 and sealing rings 8, and head plate 3 on
the housing, in the position indicated by the markings.

Check that the head plate is centred by moving it gently sideways.

Place the metal frame for N3/5

Gently tighten the screws 4 evenly and diagonally.

Turn the fan to check that the pump rotates freely.

Turn the fan again to bring the diaphragm to top dead centre.

Now tighten screws 4 firmly.
14.5 CLEANING

When changing valve plates and diaphragm, inspect all parts for dirt before assembling the
pump head and clean them if necessary.

As far as possible clean the parts with a dry cloth. Solvents should not be used as they can
attack the plastics and synthetic rubber parts. If a compressed air line is available, blow the
parts out with it.