Metering rotation angle: 45° max.
Max. rotation angle: 92° (-1°, +91°)
Torque (see the corresponding actuator tables).
The code numbers after the letters DDN, always correspond to the breakaway torque in Nm at 5,6 bar air supply.
Temperature: from 0°C to +80°C; from -20°C to +80°C with dry air only.
Air supply: 5,6 bar; maximum 8,4 bar.
Actuating media: filtered dry compressed air, not necessarily lubricated. In case of lubricated air, either non detergent oil or NBR compatible oil, must be used.
|Size||DDN 30 |
|DDN 30 |
|DDN 60 |
|DDN 60 |
|DDN 106 |
|DDN 240 |
|DDN 480 |
|4||Scotch yoke||1||Steel alloy|
|7||Int.elastic pin||1||Steel alloy|
|8||Ext.elastic pin||1||Steel alloy|
|13||Support disks||4||PTFE caric carbo-grafite|
|16||Ext.support ring||1||Acetalic resin|
|18||Centering ring||1||Aluminium alloy|
|21||Grub screw||2||Stainless steel|
|25||Intermediate cap||2||Aluminium alloy|
|26|| Adjusting nut||2||Aluminium alloy|
|29||Auxiliary piston||2||Aluminium alloy|
|30|| Auxiliary cylinde||2||Aluminium alloy|
|32||Terminal cap||2||Aluminium alloy|
|34||Grub screw||2||Stainless steel|
General use and working condition
USE: Filling and metering of fluids or solids-mix materials by means of a special metering device. Double acting actuator for fine or rough metering.
EXECUTION: With EN ISO 5211.
WORKING SYSTEM: The basic model consists of an Omal double acting actuator, equipped with two additional cylinders whose inner-pistons, by means of a stroke adjustment device, stop the rotating angle of the actuator to a pre-set position, preventing it from a complete rotation and influencing the total valve flow pressure.
This device is driven by two solenoid valves.
E1 = 5/2; E2 =3/2. E1 drives the actuator, while E2 drives the two external cylinders.
Some examples referring to the valves in the drawing above:
- with a completely CLOSED VALVE (0°) You will have:
E1: air supply in A, exhausts in B
E2: exhausts in B1.
- with a completely OPEN VALVE (90°) rough metering You will have:
E1: exhausts in A, air supply in B
E2: exhausts in B1.
When You reach the desired level, e.g. 90% of the total filling, the rough signal (completely open valve) will turn off and the air, flowing through E2 and then changing the position of E1, will get to the external pistons which will move to the desired rotating angle, e.g. 30° (fine metering), consequently reducing the total valve flow..
With an OPEN VALVE, e.g. 30° fine metering, You will have:
E1: air supply in A, exhaust in B;
E2: air supply in B1
This intermediate position and the corresponding valve flow pressure will be reproduced, whenever you repeat the process.
NOTE: Thanks to control “D”, the desired metering can range from 0° to 45°.When the desired level is the same as the actual one, the fine-metering signal on E2 (exhaust in B1) will turn off; the actuator will start moving and make the valve close, completely. Now the filling and metering process is over.
CONCLUSION: “OMAL” device can be assembled wherever you need to furnish exactly the same quantities in long working cycles.
A. FULLY CLOSED POSITION
In this position the air is supplied to port 4 with exhaust air at port 2 and 6.
B. FULLY OPEN POSITION (90° rough metering)
In this position the air is supplied to port 2 with exhaust air at port 4 and 6.
C. INTERMEDIATE POSITION (fine metering)
In this position the air is supplied to port 6 than to port 4, with exhaust air at port 2. In this case the external pistons will move to the desired rotating angle, consequently reducing the total valve flow.