Hydra-Pac Synchronous Power Units

Synchronous power units are simpler and safer than some other hydraulic pumps for jacking and skidding operations. First, they are designed for field conditions—no computers, wires, or transducers to set up or calibrate. The system is built with manual, mechanical controls. Second, they provide synchronous movement of cylinders on individual ports. The ports are not connected to each other and will give equal flow to each line regardless of the weight of the load or the pressure in that circuit.

One of the keys to the synchronous function is the split-flow, checkball piston pump. It incorporates multiple independent pistons driven by a common shaft, which ensures that each piston generates the same flow rate. Because of the relative incompressibility of oil and the sealing ability of the checkballs, the flow rate is virtually unaffected by the pressure.

Yes it is. Our Hydra-Pac power units are equipped with counterbalance valves on the pressure ports. These function to control the lowering of a cylinder that is under load by using the return-side pressure to open the valve. They act as a brake. When using single-acting jacks, there is no return line, and so we control the lowering speed by using a separate flow control. The flow control valves allow free flow in one direction (towards the cylinder) and control the flow in the other (back from the cylinder). The hydraulic hose is connected from the return port of the pump (with the flow control valve) to the cylinder port. The flow control valve is closed so that oil can only flow to the cylinder. When you wish to lower the cylinder, the flow control valve is opened gradually to allow oil to flow out of the cylinder and lower it in a controlled manner. Keep in mind that when lowering single-acting jacks, they will not necessarily be synchronized.