FESTO cylinder DSNU-10-85-P-A-MQ in stock

Brand

FESTO/German Festo

Action Method

Other

Application Areas

Chemical, Petroleum, Electronics/Battery, Electrical, General

Common Faults of FESTO Cylinders

Problems

FESTO cylinders are cast. After leaving the factory, they undergo aging treatment to eliminate the internal stress generated during the casting process. If the aging time is too short, the finished cylinder will deform during subsequent operation.

FESTO cylinders are subjected to complex stresses during operation. Besides static loads such as the pressure difference between the inside and outside of the cylinder and the weight of the components inside, they also bear the reaction force of steam flowing out of the stationary vanes on the stationary parts, as well as the forces exerted on the cylinder by various connecting pipes under hot and cold conditions. Under the interaction of these forces, the cylinder is prone to plastic deformation, leading to leakage.

Rapid load increases or decreases in the cylinder, especially rapid starts, stops, and changes in operating conditions, large temperature changes, improper cylinder warm-up methods, and premature opening of the insulation layer during shutdown maintenance, can generate significant thermal stress and thermal deformation in the cylinder and flanges.

FESTO cylinders develop stress during machining or after welding repairs, but this stress is not eliminated through tempering, resulting in significant residual stress and deformation during operation.

During installation or maintenance, improper maintenance processes and techniques can lead to inappropriate expansion clearances in the inner cylinder, cylinder diaphragms, diaphragm sleeves, and steam seal sleeves, or inappropriate expansion clearances in the lug pressure plates. This generates significant expansion forces during operation, causing cylinder deformation.

Poor quality, excessive impurities, or incorrect type of cylinder sealant can also cause problems. Hard impurities in the sealant can prevent a tight seal.

Insufficient tightening of FESTO cylinder bolts or substandard bolt material can also contribute to the issue. The tightness of the cylinder mating surfaces depends primarily on the bolt tightening. Thermal stress and high temperatures generated during unit start-up, shutdown, or load adjustments can cause bolt stress relaxation. If the stress is insufficient, the bolt preload will gradually decrease. If the cylinder bolts are of poor quality, they will elongate under thermal stress and cylinder expansion forces during prolonged operation, leading to plastic deformation or fracture. This results in insufficient tightening force and cylinder leakage.

Incorrect cylinder bolt tightening sequence. Generally, cylinder bolts are tightened simultaneously from the center outwards, starting from the point of greatest sag or deformation. This shifts the clearance from the point of greatest deformation towards the free ends of the cylinder, gradually eliminating the gap. If tightened from the sides towards the center, the clearance concentrates in the middle, forming an arc-shaped gap at the cylinder mating surface, causing steam leakage.

FESTO Cylinder Types

A pneumatic actuator that converts the pressure energy of compressed gas into mechanical energy in pneumatic transmission. Cylinders come in two types: reciprocating linear motion and reciprocating oscillating motion (see figure). Reciprocating linear motion cylinders can be further divided into four types: single-acting cylinders, double-acting cylinders, diaphragm cylinders, and impact cylinders.

① Single-acting cylinder: Has a piston rod at only one end. Air is supplied from one side of the piston, generating pressure that pushes the piston outward. It returns to its original position by a spring or gravity.

② Double-acting cylinder: Air is supplied alternately from both sides of the piston, outputting force in one or two directions.

③ Diaphragm cylinder: Uses a diaphragm instead of a piston, outputting force in only one direction. It returns to its original position by a spring. It has good sealing performance but a short stroke.

④ Impact cylinder: This is a new type of component. It converts the pressure energy of compressed gas into the kinetic energy of the piston's high-speed (10-20 m/s) motion to do work.

⑤ Rodless cylinder: A general term for cylinders without a piston rod. There are two main categories: magnetic cylinders and cable cylinders.

A cylinder that reciprocates is called a swing cylinder. A vane divides the inner cavity into two parts. Air is supplied alternately to the two chambers, causing the output shaft to swing. The swing angle is less than 280°. Other types include rotary cylinders, pneumatic-hydraulic damping cylinders, and stepping cylinders.

Technical Specifications

Stroke

1 mm ... 100 mm

Piston Diameter

10 mm

Buffer

Elastic buffer rings/pads at both ends

Mounting Position

Optional

Compliant with Standards

CETOP RP 52 PISO 6432

Structural Features

Cylinder Bore, Piston Rod, Cylinder Barrel

Position Detection

By Proximity Switch

Derivative Type

Extended external thread piston rod, one end with short external thread extended piston rod clamping unit on piston rod, axial air inlet, direct mounting, side air inlet, low friction, double-ended piston rod, high temperature resistant seals, up to 120 °C, one end piston rod

Working Pressure

0.15 MPa ... 1 MPa

Working Pressure

1.5 bar ... 10 bar

Operating Mode

Double Acting

CE Certification (see Declaration of Conformity)

Compliant with EU Explosion-Proof Directive (ATEX)

CE Marking (see Declaration of Conformity)

According to UK EX Directive

Outside EU Explosion-Proof Certification

EPL Db (GB)EPL Gb (GB)

Explosion Protection

Zone 1 (ATEX) Zone 1 (UKEX) Zone 2 (ATEX) Zone 21 (ATEX) Zone 21 (UKEX) Zone 22 (ATEX)

ATEX Gas Category

II 2G

ATEX Dust Category

II 2D

Gas Explosion-Proof Flame Retardant Type

Ex h IIC T4 Gb

Dust-Proof Explosion-Proof Flame Retardant Type

Ex h IIIC T120°C Db

Explosion-Proof Ambient Temperature

-20°C <= Ta <= +60°C

Working Medium

Compressed air, conforming to ISO 8573-1:2010 [7:4:4]

Working and Pilot Medium Description

Can be operated with lubricating media (must continue to operate with lubricating media thereafter)

Corrosion Resistance Rating CRC

2 - Medium corrosion resistance 3 - High corrosion resistance

Paint Wetting Defect Substance (PWIS) Compliance

VDMA24364-B1/B2-L

Ambient Temperature

-20 °C ... 120 °C

Impact Energy at End Point

0.05 J

Theoretical Force at 6 bar, Forward Stroke

40 N ... 47 N

Mounting Method

With Accessories

Pneumatic Connection

M5

Material Specifications

RoHS Compliant

Cap Material

Refined Aluminum Alloy

Seal Material

NBRTPE-U(PU)

Piston Rod Material

High Alloy Stainless Steel

Cylinder Material

High Alloy Stainless Steel