The hydraulic cylinder first appeared at the end of the 18th century. The hydraulic system is based on Pascal’s fluid pressure law, which states that when pressure is applied to the fluid, equal pressure will be applied in all directions of the whole fluid.
Hydraulic cylinders can be used in any application requiring strong thrust or tension. They first discovered many uses during the industrial revolution, when the increase in factories and production required a variety of hydraulic applications. Now, hydraulic cylinders are widely used in various industries, including construction, manufacturing, mining and offshore industries.
The single acting cylinder works when thrust or tension is required, so the hydraulic oil acts only on one side of the piston rod. Another force, such as gravity, the weight of a load, or a spring, operates the cylinder in the other direction.
The double acting hydraulic cylinder forces the piston rod to move forward and backward through hydraulic operation.
Telescopic cylinders use the cylinders in the cylinders to increase the distance that can be raised in one stroke. Stroke refers to the amount that the oil cylinder can lift in one movement. It is usually used for machines such as tippers, They can also be used for any additional stroke required (the amount of movement produced by the cylinder) without increasing the space required for the envelope. The telescopic cylinder can be double acting or single acting. A potential problem is that the standard telescopic cylinder will have a sudden change in speed due to the change of volume in different cylinder stages. However, professional engineering can produce double acting telescopic cylinder, which can Move at a constant speed.
The jack cylinder is a mobile cylinder with a series of dimensions. Generally, a manual pump can use multiple sizes of cylinders, which means that the company can choose the best cylinder size for each job. Jack cylinders have no supports and are usually used only on the ground. Typical lifting weights are 5 tons, 10 tons, 20 tons and 50 tons. The standard size and moving nature of Jack cylinders make them ideal tools that are not often needed. In many cases, instead of owning a hydraulic cylinder, the company leases a jack cylinder when a specific job requires it.
Pascal’s law shows that.
Force = pressure x area
In a hydraulic system, the pressure is given by the HPU (hydraulic pump unit). The area refers to the size of the hydraulic piston. These two parts determine the force that can be applied by the cylinder.
Therefore, the weight that the hydraulic cylinder can push or lift is equal to the pressure provided by the pump multiplied by the size of the cylinder rod.
Most pumps have a standard range; Typically from 3000 psi to 10000 psi (210 to 690 bar). The average is often at the low end of the range; about 210 bar. A pump can lift an infinite weight, depending on the size of the cylinder. Increasing psi may require adjusting the seal, valve and cylinder design to cope with the increased pressure.
The pump also determines the operating speed of the cylinder because it provides hydraulic oil at the necessary flow rate.
The fitting department puts all the components together (rod, pistons, tubes and seals). Purchasing from a wide variety of high-quality manufacturers, Apex Hydraulics are not tied to any one product and are able to choose the most appropriate part for each cylinder. The fitting department assembles the cylinder, ready for inspection and testing.
The in-house inspection department offers rigorous testing of all hydraulic cylinders before they are approved for the client. They perform pressure, pull and load tests as required. Apex are able to facilitate all third-party inspection agencies that may be required for offshore work, including DNV-GL, ABS and Lloyds Register.
Parts are spray painted in house. They can be painted to any required standards. Paint standards for offshore hydraulic cylinders are particularly specialised, with Norsok providing a range of that is typically approved by inspection agencies. At the point of painting, company logos or details can be added.
Raise the dump body and cylinder to full extension. Let the dump truck body stay in this position for a few minutes and let the air rise to the top of the cylinder.
Lower the dump truck cylinder until the front end of the dump truck body is about 2 feet from the chassis frame.
Place the body lifting lever in the middle / fixed position.
If your dump truck hydraulic cylinder has an external bleeder valve, open the valve. If the bleeder valve is located on the top of the cylinder, remove the tank cap with a wrench, move it to the inside of the vehicle body, and then open the bleeder valve.
Wait until all trapped air is discharged from the valve and a whole stream of hydraulic oil flows out of the valve.
At this time, the cylinder has been deflated and the vent valve can be closed.
Bleed the air from the rod cylinder-Hydraulic Cylinder Repair
Before releasing the air in the dump truck cylinder, ensure that the hydraulic cylinder is not pressurized under any circumstances. When the hydraulic cylinder is in the horizontal position, the bleeder valve should point upward. The piston rod must initially be in the fully retracted position.