|
Fischer Germany DS21 Series Differential Pressure Switch (with ATEX certified too) for safe and hazardous application, zone 1, zone 2 area
Application
These type series instruments are used as flow-operation safety device in heat carrier oil plants acc. to DIN 32 727 and hot water plants acc. to VdTÃœV data sheet flow 100. The flow-operation safety devices consist of a differential pressure device, e.g. an orifice plate, differential pressure switch and adequate shut-off valves. Follow mounting instructions in accordance to application. All instruments of this type series meet these demands. Successful structural testing of type series DS21 is confirmed by the following marks of conformity:
- for flow-operated safety devices DIN 32 727 DIN record No. 1B012/07
- acc. to VdTÃœV data sheet flow 100 TÃœV . SW/SB . 07 - 020
Construction and Operation
The monitoring and switching instrument is based on a rugged and uncomplicated diaphragm movement suitable for overpressure, partial vacuum and differential pressure measurements. The operating principle of the system is identical in all three applications. In a state of equilibrium, the forces of the springs on both sides of the diaphragm are balanced. The pressure or differential pressure to be measured creates an unbalanced force at the diaphragm. This force moves the diaphragm system
against the force of the springs for the measuring range until a new equilibrium is reached. When subjected to excessive pressure, the diaphragm rests on metal supporting plates. A centre-mounted tapped transfers the motion of the diaphragm system to the motion work and to the actuating elements of the microswitches.
Main Features
- High repeatability of switching points
- Long service life
- High overpressure protection
- Structural testing
Measuring range 0... 250 mbar up to 0... 6 bar (see ordering code) Nominal pressure 25 bar Max. static operating pressure Acc. to measuring range (see ordering code) Max. pressure load One-sided overpressure protected up to nominal pressure on (+) - and (−) side of diaphragm, partial vacuum protected Perm. ambient temperature -10... +70°C Perm. medium temperature 70°C Protection class IP 54 acc. to DIN EN 60529 Mounting position Vertical Measuring accuracy ± 2.5% FS Zero adjustment Located in the dial Contact output 1 or 2 microswitches, 1-channel change-over contacts
|
