Installation – Flowserve NRG 16-40 User Manual
Page 15
5
Attention
■
The seating surfaces of the standpipe or the flange provided on the vessel must be
accurately machined, see
Fig. 7, Fig. 12.
■
Do not bend electrode tip when mounting.
■
Use only ring joint (of stainless steel .430) D 7 x 3 (D 33 x 39 for NRG -40)
to DIN 7603 supplied with the electrode.
■
Do not lag electrode body above the hexagonal section,
Fig. 5, Fig. 9.
■
Do not insulate electrode thread with hemp or PTFE tape.
■
Do not screw electrode directly into a screwed socket,
Fig. 6, Fig. 11.
■
Observe min. spacing when installing the electrode, Fig. 10, Fig. 15, Fig. 19.
Note
■
For the approval of the boiler standpipe the relevant regulations must be considered.
■
Refer to pages 6 and 7 for typical installation examples.
Tools
■
Open-end spanner A. F. 7 mm
■
Open-end spanner A. F. 4 mm
Installation
NRG 16-40, NRG 17-40, NRG 19-40, NRG 111-40, step 1
. Screw electrode tip
D
into measuring electrode
A
, Fig. 4, Fig. 8.
. Carefully determine required measuring length of electrode. Observe min. length,
Fig. 2, Fig. 3.
3. Mark length of electrode tip
D
.
4. Unscrew electrode tip
D
from measuring electrode
A
and cut tip.
5. After visual inspection screw electrode tip
D
into measuring electrode
A
. Slide spring
C
along
electrode tip
D
, so that its bent end completely enters into small bore
B
.
■
Hacksaw
■
Flat file, medium cut
NRG 16-40, NRG 17-40, NRG 19-40, NRG 111-40, step 2
. Check seating surfaces,
Fig. 7, Fig. 12
. Place ring joint
E
onto seating surface
F
of electrode,
Fig. 5, Fig. 9
3. Apply a light smear of silicone grease (e.g. Molykote
®
) to electrode thread
G
.
4. Screw level electrode into threads of flange provided on vessel and tighten with
a 4 mm open-end spanner. The torque required is
160 Nm when cold, for NRG -40 475 Nm.
5.
When installing two electrodes together in one flange install the first electrode as described in 4.
Before mounting the second electrode undo plug
O, remove PE connection N and strip cable lugs
from the board. Screw in electrode. Slightly tighten plug
O. Install PE connection N and insert
cable lugs.
Molykote
®
is a registered trademark of DOW Corning Corp., Midland Michigan, USA