The control panelnnn
The central hydraulic control manifold contains all the equipment necessary to control the pilot valves and regulators on the subsea pods and also pressure gauges to indicate the general status of the system.
It is capable of being operated remotely from one of several remote panels and so is equipped with all the necessary electro-pneumatic solenoid valves, pressure switches and transducers in an explosion-proof enclosure.
The manifold essentially performs four functions:
- Pod selection
- Pilot manipulator valve control
- Regulator control
- Pressure readback display
Pod Selection
The pod selector valve is a 1u201d four-way manipulator valve which directs the power fluid to the active pod via the hydraulic junction box and umbilical, and vents the inactive pod to the mixed fluid tank. A 1u201d positive displacement flowmeter provides an accurate measurement to the fluid used to actuate each stack function.
The image above illustrates the Surface Selector and Subsea Manipulator Valves.
Pilot Valve Control
Pilot valve control is achieved by using u00bcu201d, 3-position, 4-way manipulator valves which are equipped with air operators for remote control. The hydraulic signal from each of these valves goes to both quick disconnect junction boxes, through both umbilical hoses and actuates the pilot SPM valves on both the active and inactive pods as shown in previous lessons.
The image belowu00a0shows a typical control valve arrangement on the control manifold. The hydraulic fluid supply goes through a check valve and charges two pilot fluid accumulator bottles. Inu00a0this way the pilot system is protected from pressure drops when power fluid is quickly consumed from the main accumulator banks.
