ASSEMBLY
MEGA PREX NK ASSEMBLY
Ensure that installation premises floor is even and perfectly horizontal.
For perfect welding, use acid or rutile cored electrodes (check codes AWS E6020 or AWS E6013 or E44LA3 or E44LC3).
- Put the boiler rear plate (1) on the floor with the hinges pointing down and ensure that it is perfectly levelled (mark the
middle of the plate sides in order to position correctly the furnace and the tube nest.
- Position the furnace (2) on the internal edge of the front plate (1) keeping the longitudinal welding of the furnace in the
lower part of the boiler.
Ensure that plate and furnace are perfectly perpendicular when coupling them.
- Weld the furnace (2) onto the front plate (1) along the outer circumference.
- Add the top tube nest part (3) (the return stub which can be recognised by its flow trap (4) welded inside the tube nest,
must be close to the front tube plate).
For positioning, ensure that the flanged stub hole axis is aligned with the
sign previously marked on the plate middle.
For easy centering, check height
A
between the tube nest edge and the
plate edge. Spot-weld the middle only.
- Position the lower tube nest (5) in respect of height
B
and spot-weld it only in the lower middle part of the rear plate (1).
- Spot-weld the two tube nest parts (3) and (5).
- Position the rear tube plate (6) and insert the tie rod or the stiffening stub (8) in the furnace.
- Weld the rear tube plate (6) and the tie rod or stiffening stub (8), carefully avoiding any damage to the four threaded
rivets or screws which will be used to secure the smokebox.
- Weld all the nest (3) and (5) onto the rear plate (1).
- Now, smoke tubes (7) can be inserted and welded on the rear plate tube (6) keeping the boiler in upright position or (but
welding will be more difficult) horizontally; the choice will depend on the size of premises and the equipment available to
turn the boiler upside down.
Warning: smoke tuber (7) must protrude 3 mm from the front plate (1) and approx. 10 mm from the rear plate (6).
- Spot-weld the drain (N4) and ensure that it is perpendicular to the front plate (1) and parallel to the tube nest.
- Position the boiler horizontally. For this reason, a lifting hook is supplied that can be conveniently welded to the tube nest
in order to simplify the boiler overturning. Remember not to have this hook protruding form the casing.
- Weld the two parts of the tube nest (5) and (6) longitudinally as well as the furnace inside (2) to the front plate (1); you
can simplify this operation by using rolls for rotating.
- Weld both 1/2” couplings (N6) onto the tube nest (3) after having ensured that the bulb sheaths inclination is correct to
avoid that sheaths are not blocked by smoke tubes; remove sheaths when welding. Weld the two flanged stubs (N1) and
(N2) for flow and return, ensuring that flanges are perfectly horizontal. Weld the instrument fitting (N3) and fittings (N5)
if included in the supply.
- Weld smoke tubes (7) onto the rear plate (1).
- Ensure that plate shapes (1) and (6) have not been altered and weld on plate surface the side frames (9).
- Weld the square tubes (10) that support the casing and, if part of the supply, weld also the side ones keeping height
C
.
- Carry out the hydraulic test under 7.5 bar pressure. FILL THE GUARANTEE WITH THE TEST DATE.
- Install the manhole (11) and the smoke box (12).
- Touch-up visible parts by using the paint supplied.
WARNING
Before start up insert turbolators in the tube nest pushing until their reach the tube plate.
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ENGLISH
Summary of Contents for MEGA PREX N Series
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