Flush Mounting In A Steel Tank - Simrad TRANSDUCER - INSTALLATION GENERIC REV H Installation Manual

Simrad Echo sounder transducers

Flush mounting in a steel tank

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Flush mounting is used on very large vessels with a hull so deep
that no air bubbles are found below the hull, and on vessels
operating in shallow harbours or waters, where a protruding
blister can not be accepted.
The standard procedure for flush mounting on a steel vessel is
to weld a steel tank inside the hull, and mount the transducer
into this tank.
Mounting and clamping rings
Circular transducers may be provided with mounting and
clamping rings, or with drawings to allow for local production of
these. The mounting ring is welded to the hole in the hull plating,
while the clamping ring fits around the edge of the transducer
body. Bolts through the clamping ring into the mounting ring
will then secure the transducer between them. Note that several
transducers use direction guides to allow correct mounting.
Smooth surface
Mounting screws or bolts must not be extruding from the hull
plating. Ensure that the surface of the transducer face, the hull
plating and putty around the transducer is as even and smooth as
possible. Obstructions on these surfaces will create problems
with turbulant flow.
Horizontal support bar
Large diameter transducers must be fitted with a horizontal
support bar. This bar can be secured to the mounting ring using
threaded rods.
Water filled
As for a blister, the interior of the tank must be filled with water.
This can be accomplished by air release through a steel tube,
which is extended either to open air 1.5 m above the water line
or to the water outside the hull at a point higher than the tank
interior. If the tube is extended to open air, drainage must be
provided with leakage at the transducer flange or a separate hole
in the tank bottom.
851-160164/H