andrews R18 Series, Техническая документация инструкция

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18IP22B
55
Replacing fin tubes
Header and manifold removal
Release water pressure and drain the unit.
Disconnect the system water-pipes at the manifold flanges.
Remove all pressure and temperature sensors from the
flow/return manifolds immersion tubes then electrically discon-
nect the flow-switch.
Remove the mounting bolts and spacers from sides of the
manifolds.
Remove the mounting bolts and spacers from sides of the
header.
Remove the manifold retaining bars (10) and carefully remove
the water manifolds, spacer plate and ‘O’-rings.
Remove the header retaining bars (10) and carefully remove
the header, spacer plate and ‘O’-rings.
Fin-tube replacement
Refer to fig. 7 for the locations of the various part numbers.
Cut a hole in the side panel directly above the tube to be re-
placed close to the tube mounting plate. This hole should be
large enough to pass the replacement fin-tube through.
From the top of the heat exchanger remove the fin-tube sup-
porting bridge (14) and two baffles (18), one on either side of
the damaged fin-tube (5),
Using a suitable tool carefully saw through the damaged fin-
tube and remove from the fin-tube mounting plates (4).
The fin-tube will be de-finned approximately 80 mm on one
side. The end of the fin-tube should be passed through the hole
and slotted into mounting plate at the other end of the unit.
Once the tube has been slotted fully into the mounting plate it
will be possible to position the replacement fin-tube between
the two mounting plates ensuring that the protruding ends are
equidistant at both ends.
Clean the bore of the replacement tube of swarf, dirt and metal
particles.
Using a small ‘G’-clamp, clamp the replacement tube to a
neighbouring tube in order to hold the replacement tube in the
correct position.
Using the correct expanding tool, expand the free tube end.
When a torque of
20 - 25 Nm has been reached the expand-
ing process is complete.
Remove the ‘G’-clamp and expand the other end also to a
torque of
20 - 25 Nm .
Replace the spacer pins, baffles (13, 16).
Wrap a suitable insulating material (article No. GIK 080) around
the exposed area to prevent overheating.
Patch the hole in the side panel and insulate.
Refit the fin-tube supporting bridge (14), the two baffles (18)
and replace the stainless steel wire ties (15).