Process industry - process engineering
Process industry - process engineering
- On which process valves (ball valves, butterfly valves) can the quarter turn actuator DRD/DRE be mounted?
The quarter turn actuator Copar is compliant with the ISO 5211 standard, which defines the interface between quarter turn actuator and process valve. The standard defines two attributes:
- Hole circle diameter and hole diameter for the mounting screws used for mounting the actuator on the valve
- Shape and dimensions of the mechanical connection between the valve and actuator shafts
To be able to select a quarter turn actuator for a particular process valve, both the flange size and the square size must be known. With the square, you also need to check whether the pipe runs parallel or is turned 45°.
- Which differences are between the DLP and standard cylinders?
The DLP has been developed specially for the particular requirements of the process industry and differs from the standard cylinders used in factory automation in essential points, the most important of which are listed below.
Point of comparison DLP Standard cylinders
speed of movement and service life
Slower, less frequent movements, designed for a service life suited to the process industry Fast, high switching cycles; designed for a long service life End position cushioning No end position cushioning With cushioning at both ends, adjustable if needed Transverse force Absorption of linear load only (transverse loading not possible) Absorption of transverse force in relation to stroke length Available diameter 80 to 320mm (no smaller diameters, as process applications usually require high loads to be moved) Up to 320mm (depending on cylinder type) Special interfaces for
connecting valves and fittings
Flange connection to ISO5210/DIN3358 for connecting valves and fittings None suitable Interfaces for direct connection of valves and accessories NAMUR hole pattern (VDI/VDE 3845) for direct connection of solenoid valves and accessories None suitable
- Can a single-acting semi-rotary actuator be converted from “closing with spring force” to “opening with spring force”?
A single-acting quarter turn actuator can be ordered in versions which close or open with spring force. The difference lies in the 180° rotation of the pistons, so that the shaft rotates in the opposite direction to normal. When converting a quarter turn actuator from one that closes with spring force to one that opens with spring force, the pistons must be rotated 180°. Rotating the pistons causes the racks on the opposite side of the shaft to take hold, forcing the shaft with the force of the springs to rotate to the left.
- Can a quarter turn actuator type DRD/DRE also be operated manually?
The upper shaft end of the quarter turn actuator is designed in such a way that the drive can be operated manually with the aid of a typical open-end spanner. Actuations of this kind do not affect the service life or function of the drives.
However, very large drives require very high forces and large levers to set the drive shaft in motion.
- Can the ball valve drive units type VZPR replace the previous (no longer available) type (CR)QH-DR units?
The ball valves of the VZPR units have exactly the same dimensions as the ball valves of the (CR)QH-DR units up to sizes 1/4" and 3/8" (brass design) and 1/4" (stainless steel design). That ensures their replaceability by the VZPR units. The installation dimensions of the pneumatic actuator, however, differ from those for previous actuators, but in most applications the dimensions of the ball valve will be the decisive factor.
- Which specifications must be known in order to configure a Copar?
- The wide variety of design principles and materials for process valves such as ball valves and butterfly valves makes it necessary to examine each application in detail so that the right valve/actuator combination can be chosen and a suitable size selected.
- What is the difference between quarter turn actuators type COPAR (DRD/DRE) and type SYPAR (DAPS)?
The quarter turn actuator SYPAR (Scotch-Yoke-Pneumatic-Actuator-Rotative) is based on the second most important operating principle for quarter turn actuators in the process industry, the Scotch yoke principle.
Whereas the COPAR has linear torque characteristics due to its rack & pinion principle, the torque curve for the SYPAR is non-linear. This property is produced by the lever arm moving through the entire swivel angle (0°-90°). Accordingly, with the design of a SYPAR actuator special attention must be paid to three factors. These behave as follows:
0° initial breakaway torque, maximum rotational torque Mmax = 100%
45° Minimum rotational torque Mmin = 0.5 x Mmax
90° Torque at the end positions Mend = 0.75 x Mmax
The way the torque output varies is thus the most important difference between these two actuators.
- Can pneumatic actuators and supply lines freeze in the winter?
- Water is always present in the air in the form of natural air humidity. When the compressed air cools in winter (in pipes and actuators which are located outside) water condenses and ice can form. We recommend the use of compressed air preparation suited to the application with a condensate separator and an air dryer.
- Does the quarter turn actuator DRD/DRE (Copar) come with end-position cushioning?
The quarter turn actuator DRD/DRE (Copar) does not come with end-position cushioning. In the process industry, this actuator is generally only required to perform slow movements, so adjustable end-position cushioning is not necessary. The cushioning function of the valve seal is sufficient in most cases.
- Is there a replacement parts kit for Copar DRD and DRE semi-rotary actuators?
- There is a spare part kit for all sizes of the Copar quarter turn actuator, containing all seals, O-rings, slip rings, both shaft bearings and the retaining ring for the shaft. All parts must be installed during a repair, as seals could be damaged when the actuator is disassembled.
- Can the Copar semi-rotary actuator also be used for factory automation?
- The quarter turn actuator Copar has been developed specially for applications in the process industry and consequently meets the criteria required in that industry. It can also be used in some applications in factory automation, although these do require a very precise analysis.
- Aren’t pneumatic actuators overly expensive?
- Pneumatic actuators are powered by compressed air. The compressed air is produced by a compressor. Electromechanical valve actuators draw their power from the mains supply. Comparing the operating costs (power costs) of these two forms of actuators shows the cost advantages of the pneumatic actuators. From the point of view of cost, it is important to design the compressed air system (compressor and reservoir) to suit actual requirements.
- Can the Copar actuator also be used to actuate 3-way ball valves?
There are numerous designs of 3-way ball valves, many of which can be actuated with the Copar. To be able to design a 3-way ball valve with actuator, the following points must be known:
- Hole in the ball in “L” or “T” shape
- Rotation angle required: 90°, 180° or 360°
- Can the Copar actuator also be used to actuate 4-way ball valves?
Yes, various designs can be actuated with the Copar, but the 4-way ball valves must have a rotation angle of no more than 180°. In addition to application data such as pipe pressure, medium, temperature of medium, working pressure of the actuator and required materials for the ball valve, the following points must be known:
- Hole in the ball in “L” or “T” shape
- Rotation angle required: 90°, 180° or 360°
- Are pneumatic actuators controllable?
- Yes. The actuators Copac and Copar can be regulated using common commercially available positioners. A specific variable speed drive, designed for e.g. annular piston valves, is currently planned. Festo can provide advice and support when selecting and planning variable speed applications. Intermediate positions are always possible with Festo actuators.
- Can I replace a competitor’s actuator with a Copar?
- Most quarter turn actuators in the process industry are compatible and can be interchanged. The torque of the Copar must be at least as high as that of its competitor. The interface between actuator and valve must also be precisely defined, so that the valve can be fitted with adapters if necessary.
- Can the QH-DR-E-... limit switch module be used with the Copar?
- The function of the limit switch QH-DR-E-… can be applied with quarter turn actuators Copar in all sizes. All three variants, electric, inductive and pneumatic, can be used as sensor boxes for the Copar. The shape and size of the mechanical connection between the actuator shaft and sensor box shaft are standardised and identical for all actuators. However, the German standard VDI/VDE 3845 permits a range of dimensions for the mounting bracket for mounting the sensor box on the actuator. The mounting bracket supplied with the sensor box QH-DR-E (hole pattern 80x30mm) only fits Copar sizes 4 to 26.
- Can the Copar actuator also be used for 180°?
- The quarter turn actuator Copar can also be supplied as a 180° actuator. The double rotation angle is achieved by an addition between the rack and pinion. The rack is machined so that it has double the number of teeth. An adapter with different sized teeth on either side is screwed onto the piston rack as a counterpart. One side matches the piston rack and the other matches the teeth on the shaft. The halving of the teeth module and the consequent doubling of the teeth means that the shaft can reach double the angle with the same piston stroke. The modification means that only half the torque will be achieved when compared with a standard actuator of the same size.
- Can the quarter turn actuator DRD/DRE (Copar) actuator also be used for regulating liquids?
Fully variable control of the Copar with a 4-20mA signal is possible by mounting positioners on the standardised interface. This can be done with single and double-acting actuators. While simple positioners only react to electric signals, more complex versions can also be equipped with special modules and additional functions such as feedback/diagnostics. That is why it is vital to have as much information as possible about the application and its requirements before selecting a positioner.
- Can the quarter turn actuator DRD (Copar) be converted from double to single-acting?
- A double-acting Copar DRD can be converted from double to single-acting by installing springs. There are special springs for every actuator size, with the right size and spring rate. The number of springs can be determined using the torque tables for single-acting quarter turn actuators DRE-xx-xx in Info 910. The first step is to undo the screws and remove the cover. Then the springs are installed. Careful attention needs to be paid to the positioning of the clockwise rotating and anti-clockwise rotating springs on the pistons. When screwing the cover back on afterwards, the screws must be tightened evenly in a criss-cross pattern to prevent tilting.
- Can the quarter turn actuator DRD (Copar) be used to replace the DRQD rotary drive?
- Whereas the Copar was specially developed for the process industry, the DRQD is a classic product for factory automation. The specifications in these two areas of application differ greatly, with each requiring its own special products. For this reason, the Copar DRD/DRE and the DRQD are not compatible and can therefore only be interchanged in very few cases.
- Can the CR-QH-DR ball valve actuator be replaced with the quarter turn actuator DRD (Copar)?
- The Copar and the quarter turn actuator of the CR-QH-DR both work according to the rack & pinion principle and are therefore fully compatible. However, the CR-QH-DR is only available as a double-acting quarter turn actuator, so it can only be directly replaced by the double-acting Copar DRD. The quarter turn actuator of the CR-QH-DR is identical to that of the QH-DR. The Festo designation “CR” for increased corrosion resistance refers only to the three-part ball valve made from stainless steel. If the actuator used in the application also needs to be highly corrosion resistant, the Copar with increased corrosion resistance “C” should be used.
- Can the QH-DR ball valve actuator be replaced with the Copar?
- The Copar and the quarter turn actuator of the QH-DR work according to the rack & pinion principle and are therefore fully compatible. However the QH-DR is only available as a double-acting quarter turn actuator, so it can only be directly replaced by the double-acting Copar DRD. Please note the interfaces for the ball valve (flange and square) and the torques.
- Can the swivel range of the DRD/DRE (Copar) be limited to less than 90°?
- Yes. This involves using longer screws for the covers to shorten the stroke of the piston, thus reducing the rotation angle of the actuator shaft.
- Is the swivel range of DRD/DRE (Copar) limited to 90°?
- Yes. The quarter turn actuator Copar can also be supplied for greater rotation angles. To achieve a rotation angle between 90° and 180°, longer limit position screws are used than in the standard actuators. This enables the piston stroke to be shortened or adjusted in any way. As a result of the modification, only half the previous torque is achieved.
- Can the Copar actuator be manually actuated?
- The upper end of the quarter turn actuator DRD/DRE shaft can be turned by hand with the aid of a typical open-end spanner. This has no effect on its service life or function. However, very large actuators require very high forces and large levers to set the shaft in motion. If a limit switch box is directly mounted, the Copar can only be actuated manually if the mounting bracket has a cut-out which enables the spanner to be rotated through 90°.
- What do the KBK classes signify?
The CRC mark represents corrosion resistance classes. These have been defined by Festo in the standard FN 940 070. To define the CRC class of a product, the product must be subjected to four different tests:
- W/K= hot/cold aging (+120° C/-20° C)
- KFW= condensation cycle DIN 50 017 - KFW
- SO2= Kesternich test acc. EN ISO 6988 KFW 0.2 S
- SS= Salt-spray mist with NaCl solution (5%) DIN 50 021 - SS