Sizing Closed loop "return" hoses

[FreakyOens]

Hello!

I'm currently trying to design a closed-loop system, and I think I pretty much have most details down except for the "return"/ "suction" side of the circuit.

I understand that for an open-loop system, I would need to size return lines from my components outlets to the tank, and have a single suction line from the tank to the pump's inlet. So how would this play out for a closed-loop system? The way I have it designed is that the outlets of whatever components I have (including tank) are all directly connected to the pump's inlet, so I'm not sure if I should size that single hose to have a flow velocity of 2ft/s or go a completely different route.

Right now, I'm planning on sizing the "return"/"suction" lines to the diameter of my pump's outlet, but this feels like an unconventional way of doing this.

 

[oldnslo]

If this is a true hydrostatic closed loop system both hoses between the pump and motor are the same size

 

[Rich B1]

Like oldnslo said, a true closed loop has 2 lines from the pump to the motor, both the same size.

You will have a suction, more like change line, from the reservoir to charge port of the pump. There should be case drains from the pump and motor. All should be sized to the port size (-8, -12, etc.). You may have some smaller lines for assorted control pressures.

 

[Zebrafive]

No expert, so just my observation, suction hoses are sized larger than output hoses.

 

[oldnslo]

Zebra,
In a closed loop system the only suction hoses are for the charge pump since both motor ports are connected directly to both pump ports. This is why it it called closed loop. any flow from the pump goes through the motor and straight back to the pump.

 

[LouNY]

The way I have it designed is that the outlets of whatever components I have (including tank) are all directly connected to the pump's inlet,

This does not sound like a closed loop system, it sounds more like a closed center system with multiple users off the single pump.
I would return all components to the tank with a larger single feed from the tank to the pump inlet.
Are you planning on a suction or return line filtration system.
The suction feed would need to be a larger line then the discharge because of the pressure differences.

 

[LouNY]

The way I have it designed is that the outlets of whatever components I have (including tank) are all directly connected to the pump's inlet,

This does not sound like a closed loop system, it sounds more like a closed center system with multiple users off the single pump.
I would return all components to the tank with a larger single feed from the tank to the pump inlet.
Are you planning on a suction or return line filtration system.
The suction feed would need to be a larger line then the discharge because of the pressure differences.