[LW] [LW11] Pump position

[engenharia2]

Hey Guys, How are you?

I work on Marine Express from Brazil and we represent Raymarine here, all the time that we need determine a autopilot to a new client and I always have doubts if what I indicated was right, and once more time I need your help. I attached the steering system from a new shipyard but I don't know exactly where I need put the pump, Can you help me? I put number in red on the hoses to make easy the identify where is the best place. Should I put between 2 and 4?

Thanks in advance.

Felipe Muniz

[Derek - Raymarine - Moderator]

Hi Felipe,
thank you for your message,

The system in the attached diagram indicates an engine driven form of power assisted steering where the helm pumps(steering wheels) are used to direct the high pressure oil to the steering rams.

In this system, you would normally connect the autopilot pump between pipes 2 and 4, as close to the steering rams as practical and the reservoir line from the pump should be connected to the low pressure return line to the oil reservoir.

You should also check that there are check valves in the helm pumps too, otherwise the autopilot pump will pump oil into the helm pumps instead of the steering rams.

Thanks
Derek

[engenharia2]

Derek

thank you for the answer, but unfortunately the cubic capacity will be about 1500 cc, before I receive this information I was thinking about in ACU 300 with constant running but this pump is 1200cc. Do you know any solution for this? Attached is the specification about the surface drive used on this boat, for better undertand.

Thank in advance

[Derek - Raymarine - Moderator]

Hi Felipe,

Thank you for the feedback, at 1500cc this is a very big ram, is it possible to doublecheck this and confirm the ram is single or double acting? is there only one ram too? ( As shown in the attachment you sent).
Can you identify the full extent of the travel of the ram, although it might have a total capacity of 1500cc, does it use the full stroke from fully port to fully starboard?

If it is 1500cc and does use the full travel, then you would need to use the ACU300 and a solenoid operated constant running pump with a flow rate of something like 9litres/min, ideally an adjustable flow rate up to this level would be an advantage, since you can then tune the flow rate to suit the characteristics of the boat. bear in mind that at higher speeds the rudder will need to move much less and slower too.

Thanks
Derek