Installation Of Bottom Parts - JRC JLN-900 Installation And Instruction Manual

3.

Installation of Bottom Parts

Detailed instructions for installing the different Bottom Parts are given in the following
sections. Refer to the section covering your particular application.
The Bottom Flange, which shall be welded into the ship's hull, is the same size whether it is
for the single or double Bottom Parts.
The Bottom Flange dimensions can be seen in Fig. 1.2 and Fig. 2.2.
Unpacking of Bottom Flange
The Bottom Flange, which shall be welded into the ship's hull, is made of construction steel.
Humidity makes the surface of the flange corrode if not protected. The flange is therefore
protected from corrosion during storage and transport by a special corrosion inhibitor bag.
This bag should remain sealed during storage for the corrosion protection to have full effect.
The bag shall be opened just before the flange is to be welded into the ship`s hull.
After completed welding work it is recommended to slightly oil/grease the flange surfaces in
order to prevent further corrosion until installation is completed.
Do not paint the outboard interior of the Bottom Flange nor the inboard flange gasket area
or threaded stud bolt holes!
Slight normal corrosion on the flange surface will not affect the function, lifetime or quality.
Maintenance of Bottom Parts
Each bottom part assembly incorporates a Zinc Ring that acts as a sacrificial anode to prevent
corrosion of the Transducer and Bottom Parts. The Zinc Ring should be checked, and changed
if deteriorated, each time that the ship is dry-docked.
When maintaining the Bottom Parts it is also recommended to check and tighten the Tube
Bracket clamping arrangement.
The Guide Ring, Zinc Ring or the TRU shall never be painted!
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