7 ND90 71 en
33
Spool valve removal is only possible in the spring-
forced failsafe position of the spool. In the case of a
stuck spool it might be necessary to remove the sec-
ondary diaphragm cover (167), the spool spring
(166) with its disc (164) and the secondary dia-
phragm (162) with its plate. After the removal of
these parts it is possible to use a punch to force the
spool to the failsafe position.
The spool valve may be cleaned if special attention is
paid to a clean environment and proper procedure.
Clean the spool and the bore of the body with care.
Do not leave any fibres from cleaning materials in
the bore or on the spool. Do not scratch the mating
surfaces of the spool and body.
6.2.2 Installation
ND9100, ND7100
Ensure that the gasket (174) is properly located in
the groove on the bottom of the spool valve assem-
bly. Mount the spool valve assembly on to the hous-
ing and tighten the M3 and M4 screws evenly.
Ensure the O-ring (140) slots inside the groove fully.
Mount the prestage unit directly on the spool valve
unit as in 6.1.
ND9200, ND7200, ND9300
Ensure that the gaskets (174) and (63) are properly
located in their grooves on the bottom of the hous-
ing. Mount the spool valve and the spool valve cover
(61) to the housing, and tighten M4 screws evenly.
6.3
Flame arrestor assembly
ND9200, ND7200, ND9300
The flame arrestor and the restrictor are fit into the same
plug which is located under the diaphragm cover (171). This
assembly can not be disassembled and should be replaced
if clogged.
To remove the flame arrestor assembly, unscrew the
screws (173, 4 pcs.) and remove the diaphragm cover
(171) with its O-ring. Turn a M3 screw into the
threaded hole of the flame arrestor assembly to
extract it from the housing. Installation is the rever-
sal of removal. Place the O-rings carefully.
6.4
Diaphragms
ND9200, ND7200, ND9300
The diaphragms (169, 162) may be replaced by removing
the respective covers (171, 167). The unit should be
unmounted from the actuator and the side to be worked on
turned upwards in order to avoid loss of small parts. When
replacing the secondary diaphragm (162), the spool spring
(166) with its guide (164) has to be removed first. When
reassembling, pay special attention to the installation of the
diaphragms and O-rings.
6.5
Communication board
6.5.1 Removal
ND9100, ND7100
Loosen the M8 grub screw (110) off the position indi-
cator (109) and turn the position indicator from the
shaft. Remove the cover of the prestage (43).
Remove the electronics cover (39) attached with M3
screws (42, 4 pcs.).
Remove the M3 screws (217, 4 pcs.). Hold the sides of
the circuit board and lift it directly upwards and out-
wards. Handle the board carefully, touching only the
sides.
ND9200, ND7200, ND9300
Loosen the M8 stop screw (110) in the position indi-
cator (109) and turn the position indicator from the
shaft (11). Remove the inner cover (39) attached with
M3 screws (42, 3 pcs.).
Remove the M3 screws (217, 4 pcs.). Hold the sides of
the circuit board and lift it directly upwards and out-
wards. Handle the board carefully, touching only the
sides.
NOTE:
If the maintenance operations have been done for the
spool valve assembly, the device
must
always be cali-
brated.
Fig. 34
Spool valve assembly, ND9100 and ND7100
195
194
140
160 174 175
0327000170
Assembly direction of spool
Sticker on fastener (160)
Fig. 35
Spool valve assembly, ND9200, ND7200
and ND9300
NOTE:
Ground yourself on the body of the device before touch-
ing the circuit board.
NOTE:
Do not remove the Valve Controller Board (210)!
Removing the board will void the warranty.
195
174 194
63
61
Sticker
