Documents are only to be used and distributed completely and unchanged. It is strictly the users’ responsibility to check carefully
the validity of this document with respect to his product. Manual-no.: 999155 / 29/01/2009
page 26 of 36
Assembling pump heads
➨
Bring the diaphragms into a position in which they are in
contact with the housing and centred with respect to the
bore.
➨
ME 8 NT, MD 4 NT, MV 2 NT
: When mounting the hous-
ing cover, install the connecting tube (1) under the pump
between the two housing covers. Pay attention to the cor-
rect positions of the seal rings (replace if damaged) in the
grooves at the ends of the tube. Stick the connecting tube
in the bore of the housing cover. After the assembly the
connecting tube may have some play.
Reassemble in reverse order.
➨
Install head cover, valves, O-rings (not ME 8 NT) and
housing cover.
☞
Make sure that the diaphragm stays centric so that it will
become clamped uniformly between housing and head
cover.
➨
Put the head cover onto the housing.
☞
Orientation of the head cover: Align the nib at the head
cover with the notch of the housing cover.
➨
Put the valves in place. In case install O-rings.
☞
Make sure that the
valves are correctly seated
: Valves at
the outlet with round centred opening under valve, valves
at the inlet with kidney-shaped opening of the head cover
(2) beside valve.
➨
Only MZ 2D NT
: Installing the white PTFE valves: at outlet
of 1st stage and at inlet of 2nd stage (see fig.).
(2)
(1)
☞
Pay attention to washers. Do not remove, assemble the
original number of washers between the support disc and
the connecting rod.
➨
Screw diaphragm clamping disc, diaphragm, diaphragm
support disc and washers (if applicable) to connecting
rod.
➨
Optimum torque for the diaphragm support disc:
6 Nm
,
use torque key. Attach torque key to diaphragm key (hex-
agonal bolt 6 mm wide).
➨
Position the new diaphragm between the diaphragm clamping
disc with square head screw and the diaphragm support disc.
☞
Attention:
Double diaphragm! Put the two diaphragms to-
gether with the printed sides outwards (not MZ 2S NT).
☞
Attention
(only MZ 2S NT): Position diaphragm with pale
side towards diaphragm clamping disc (to pump chamber).
☞
Make sure that the square head screw of the diaphragm
clamping disc is correctly seated in the guide hole of the
diaphragm support disc.
➨
Lift the diaphragm at the side and position it carefully
together with the diaphragm clamping disc and the dia-
phragm support disc in the diaphragm key.
☞
Avoid damage of the diaphragm: Do not bend the dia-
phragm too much.
