442703/B
139
Connectingaventilationpipetotheair
bleedingcock
Airinsidetheinstallationtrunkmaydamagethetransducer.Thehullunitmounting
angeisprovidedwithandedicatedcocktoreleaseanytrappedairfrominsidethetrunk.
Prerequisites
Theshipyardmustprovideallnecessarytoolsandmanpower.
Thefollowingspecicitemisrequiredforthistask.
•Ventilationpipe(Theminimumdiameteris1/4"(6.35
mm).)
Illustration:
AVentilationpipe
BPipethread
CValveshowninopenedposition
Thefollowingspecialtoolsarerequiredforthistask:
•Plumbingtools
Procedure
1Mountaventilationpipetotheairbleedingcock.
2Runthisventilationpipewithacontinuousrisetothemaindeckoroutthrough
thevessel'sside.
3Opentheairbleedingcockonthehullunitmountingange.
Relatedtopics
Installingthehullunit,page124
Hullunitinstallationoverview,page125
Designingandmountingmechanicalsupport
bracketstosecurethehullunit
Duetoitsheightandweight,thehullunitgantrymustbesecuredtothebulkheadby
meansofmechanicalsupportbrackets.Thedimensionsandstrengthofthesupport
bracketsmustbeadequatetopreventvortexinducedvibration.Thisarequirementto
ensurethesafetyoftheST90andthevessel.
Prerequisites
Theshipyardmustprovideallnecessarytoolsandmanpower.
Installingthehullunit