5
Attention
n
The seating surfaces and threads on the vessel and mounting flange must be accurately
machined,
Fig. 10
n
Use GESTRA PN 60 hat flange when applying the equipment in a high-pressure steam
boiler.
n
Do not bend the electrode tip when cutting.
n
Use only the supplied ring joint 27 x 32, form D, DIN 7603, .430, bright-annealed.
n
Do not lag the electrode body.
n
Do not insulate the threads with hemp or PTFE tape.
n
Do not apply conductive paste or grease to the electrode thread.
n
Provide a min. spacing of 4 mm between electrode and earth (flange, boiler wall).
n
Observe the minimum distances for the installation of the electrode.
Installation
NRG 16-12, NRG 17-12, NRG 19-12, step 1
. Screw electrode tip
4
into measuring electrode
1
,
Fig. 7
2. Carefully determine required measuring length, taking minimum length into account.
3. Mark length of electrode tip
4
.
4. Unscrew electrode tip
4
from measuring electrode
1
and cut tip.
5. Screw electrode tip
4
into measuring electrode
1
and tighten. Slide spring
3
along electrode tip
4
, so that its bent end completely enters into small bore
2
.
6. If a measuring surface extension is required slip disk
6
onto electrode tip
5
ensuring that the
electrode tip protrudes 2 mm from the bottom of the disk. Fasten disk with set screw
7
.
Push star-lock washer
6
over electrode tip against disk.
NRG 16-12, NRG 17-12, NRG 19-12, step 2
. Check seating surfaces,
Fig. 10
2. Place joint ring
8
onto seating surface
9
of electrode,
Fig. 8
3. Apply a light smear of silicone grease (e. g. Molykote
®
) to electrode thread
0
.
4. Screw level electrode into threads of flange provided on vessel and tighten with a 36 mm ring
spanner. The torque required is
160 Nm when cold
.
Molykote
®
is a registered trademark of DOW Corning Corp., Midland Michigan, USA
