Most problems that occur in hydraulic pressure intensifiers happen as a result of one of these seven reasons:
1: Contamination of the fluid
If the oil is contaminated it is the danger of 1, particles will be caught between the seat and the ball of the check valves. This will result in the intensifier continuously working, but will not be able to build up pressure.
Also Particles in the oil may be moved along the grinded bores 2, and destroy the surface, which will lead to internal leakage over the pistons.
To avoid these problems a pressure filter should be inserted before the intensifier.
2: Too high inlet flow
If the maximum values for inlet flow is exceeded, the springs in internal check valves will be compressed to much, and the check valves will be destroyed. Also to high inlet flow will mean the piston speed will be too high, and cavitation may occur. To avoid these problems, the inlet flow—for both P and T—should be controlled.
3: Large volume under pressure
In applications with a large volume under pressure, the activating of the internal pilot-operated check valve will cause a very high flow rate in a very short time inside the intensifier.
This high flow rate might be many times the max. allowable flow rate to the intensifier, and due to the compact design of the Scanwill intensifiers, the flow passes by the internal check valves, which will be destroyed due to the excess flow.
The solution is to limit the flow back through the intensifier, and use an external pilot-operated check valve—designed for the flow—parallel with the intensifier.
4: Too high inlet pressure
Exceeding the max. inlet pressure for the Scanwill intensifier used, will result in the screws holding the body parts together to stretch. This will result in the static O-rings between the body parts to be pushed out, and the Intensifier will be leaking. Also if the screws stretch, the internal leakage will increase, and the intensifier will not be able to increase the pressure as supposed to.
5: Heat input
In situations where the fluid is heated in an uncontrolled way, e.g. due to the sun warming up a cylinder or hoses, the fluid might get very thin and loose its lubrication. This will result in the pistons inside to getting stuck in the bores, and the intensifier cannot work. To avoid this sufficient cooling should be applied. Also it should be considered to choose an intensifier setup, where the oil from the high pressure side always is lead back to tank, when relieving the pressure.
6: Return pressure
The Scanwill intensifiers intensify the differential pressure between the P and the T inlet ports. In applications with high back pressure in the T-line, the expected end pressure might not be obtained. In these situations, a separate T-line for the intensifier should be considered.
7: Air in the oil
Air in the oil is absolutely unwanted. This will result in the damage of internal parts as valves and pistons, and the performance of the intensifier will be unpredictable. To avoid this the system should be designed, so no pockets of trapped air can occur.