This article describes how to bleed air from our standard Through-Hull Deployment Machine.
This normally only needs to be done once, at the commissioning stage following installation.
Having a properly-bled system improves system performance. In some instances, bleeding the system is the cure for old, rarely-used machines.
Procedure
- Start with the pole at the top position, with the locking pin in the gantry hole, as shown in the image above.
- Ensure the HPU tank is filled with hydraulic oil just above the Max level of its glass gauge.
- Disable the top sensor, so that the TOP light does not illuminate; see Note below.
- Press the UP button.
- Make sure the locking cylinder pin fully retracts.
- Hold the UP button for about 30 seconds.
- Release the UP button and immediately press the DOWN button (so that the pin does not have chance to retract until the pole is below the gantry hole).
- Release the DOWN button when the pole has been lowered below the hole.
- Enable the top sensor.
- Press the UP button until the flag reaches the sensor, and check that the pole automatically stops, and the pin extends into the hole.
- Top up the tank if required.
- Exercise the pole up and down a few times.
- Top up the tank to its maximum level with the pole at its top position.
Note
Disabling the top sensor can be performed in a number of ways. Choose one of the following methods:
- Bend the sensor flag outwards a small amount, so that it fails to activate the proximity sensor.
- Remove one of the supporting bolts and loosen another, so that the sensor flag rotates downwards, thereby again failing to activate the proximity sensor.
- Remove the wire from terminal 10 (from any side of the terminal block, whichever is easier) inside either the Local Control Unit or the Main Control Unit.