Installing the gate valve
The gate valve must be mounted so that its top mating surface is in parallel with the sea surface during normal operating conditions. The transducer dock on top of the gate valve must remain vertical during the same conditions.
Prerequisites
This task must take place in dry dock. The shipyard must provide all necessary tools and manpower. The following specific items are required for this task.
•  Silicone grease
•  Anti-seize lubricant
•  Torque wrench
•  Lifting arrangement
•  O-ring
•  Mounting hardware
Note
The gate valve is heavy. Appropriate lifting equipment (lifting tackle, portable crane or ship’s crane) is required. Always use appropriate lifting equipment to minimize risk of personnel injury or equipment damages. Only certified equipment must be used.
It is assumed that the mounting flange has been installed correctly.
Context
Only the basic steps of the task are offered. Additional procedures with more information and/or details must be provided by the installation shipyard to fit the vessel properties.
The top mating surface of the gate valve must be protected with a wooden cover at all times until the transducer dock is installed. It is very important that this surface is clean and undamaged, because it must be watertight after the transducer dock has been installed.
Procedure
1 Attach the necessary tackles to the gate valve, and make sure that the unit is lifted with the correct side up.
The gate valve will work in any position, but we recommend that it is mounted with its identification tags and classification markings facing up. You must also consider the access to the end switches, and (if relevant) the hydraulic hose connections.
2 Lower the gate valve down into the hull unit compartment, but stop when the unit is a few centimetres above the mounting flange.
Note
Do not damage the mating surfaces on the valve, the end switches, or (if relevant) the hydraulic actuator.
3 Verify that the mating surface on the valve is clean and undamaged.
4 Prepare the mounting flange.
a Remove the protective cover from the mating surface on the mounting flange.
b Verify that the mating surface on the mounting flange is clean and undamaged.
c Wipe a thin film of silicone grease on the O-ring and place it in the groove on the mounting flange.
5 Attach the nuts and washers while the gate valve is still suspended.
Due to the limited space, it may be difficult to enter and/or tighten some of the nuts. An alternative is then to use Loctite 270 or similar.
6 Lubricate the threads with a high grade commercial anti-seize lubricant.
7 Lower the valve carefully onto the mounting flange while tightening the nuts.
8 Verify that the valve is orientated and aligned correctly.
9 Disconnect and remove the tackles from the gate valve.
10 Tighten the nuts to torque 472 Nm.