German Festo FESTO cylinder ADVU-12-20-A-P-A

German Festo FESTO cylinder ADVU-12-20-A-P-A

FESTO cylinders are cast and undergo aging treatment after leaving the factory to eliminate internal stresses generated during the casting process. If the aging time is short, the processed FESTO cylinder will still deform during future operation.

The force situation of FESTO cylinder during operation is very complex. In addition to static loads such as the pressure difference between the gas inside and outside the FESTO cylinder and the weight of various components installed inside it, it also has to bear the reaction force of steam flowing out of the stationary blade on the stationary part, as well as the force of various connecting pipelines in cold and hot states on FESTO cylinder. Under the interaction of these forces, FESTO cylinder is prone to plastic deformation and leakage.

The load on FESTO cylinders increases or decreases too quickly, especially during rapid start-up, shutdown, and changes in operating conditions, with large temperature fluctuations, incorrect cylinder warming methods, and premature opening of insulation layers during shutdown maintenance, resulting in significant thermal stress and deformation in FESTO cylinders and flanges.

The FESTO cylinder experiences stress during mechanical processing or after welding repair, but the FESTO cylinder has not been tempered to eliminate it, resulting in significant residual stress and deformation during operation.

During installation or maintenance, due to maintenance processes and techniques, the expansion gaps of the inner cylinder, FESTO cylinder partition, partition sleeve, and air sleeve are not suitable, or the expansion gaps of the hanging ear pressure plate are not suitable, resulting in a huge expansion force after operation and causing the FESTO cylinder to deform.

The FESTO cylinder sealant used has poor quality, excessive impurities, or the wrong model; If there are hard impurity particles in the FESTO cylinder sealant, it will make it difficult for the sealing surface to bond tightly.

The tightening force of FESTO cylinder bolts is insufficient or the material of the bolts is not qualified. The tightness of the FESTO cylinder joint surface is mainly achieved by the tightening force of the bolts. The thermal stress and high temperature generated during the start stop or load increase/decrease of the unit can cause stress relaxation of the bolts. If the stress is insufficient, the pre tightening force of the bolts will gradually decrease. If the bolt material of the FESTO cylinder is not good, the bolt will be stretched and undergo plastic deformation or fracture under the action of thermal stress and FESTO cylinder expansion force during long-term operation, resulting in insufficient tightening force and leakage of the FESTO cylinder.

The sequence of tightening FESTO cylinder bolts is incorrect. The general FESTO cylinder bolts are tightened from the middle to both sides simultaneously, that is, from the vertical arc zuida or the deformed zuida under force. This will transfer the gap at the deformed zuida to the free ends before and after the FESTO cylinder, and eventually the gap gradually disappears. If it is tight from both sides to the middle, the gap will concentrate in the middle, and the FESTO cylinder joint surface will form a bow shaped gap, causing steam leakage.

German Festo FESTO cylinder ADVU-12-20-A-P-A

FESTO cylinder is composed of cylinder barrel, end cover, piston, piston rod, and sealing components.

The inner diameter of the FESTO cylinder barrel represents the magnitude of the cylinder output force. The piston should slide smoothly back and forth inside the cylinder, and the surface roughness of the cylinder should reach Ra0.8um. For steel pipe cylinders, the inner surface should also be plated with hard chromium to reduce frictional resistance and wear, and to prevent rusting. In addition to using high carbon steel pipes, the cylinder barrel material is also made of high-strength aluminum alloy and brass. Small cylinders use stainless steel pipes. Cylinders with magnetic switches or cylinders used in corrosion-resistant environments should use materials such as stainless steel, aluminum alloy, or brass for the cylinder barrel.

FESTO single acting cylinder: Only one end has a piston rod, and gas is supplied from one side of the piston to generate air pressure. The air pressure pushes the piston to generate thrust and extend, returning by spring or self weight.

FESTO double acting cylinder: alternate air supply from both sides of the piston, outputting force in one or two directions.

FESTO diaphragm cylinder: using diaphragm instead of piston, only outputting force in one direction, and resetting with spring. It has good sealing performance, but short stroke.

FESTO impact cylinder: This is a new type of component. It converts the pressure energy of compressed gas into the kinetic energy of high-speed (10-20 meters/second) movement of the piston to perform work. The impact cylinder has added a middle cover with nozzles and discharge ports. The middle cover and piston divide the cylinder into three chambers: the storage chamber, the head chamber, and the tail chamber. It is widely used in various operations such as cutting, punching, crushing, and forming. The cylinder that oscillates back and forth is called a swing cylinder. The inner cavity is divided into two by blades, and the two chambers are alternately supplied with gas. The output shaft oscillates with a swing angle of less than 280 °. In addition, there are rotary cylinders, gas-liquid damping cylinders, and stepper cylinders.