PRECISION Instruments, Valves & Manifolds

"The New Standard"

400 DGC

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These quality differential pressure instruments designed to measure the difference in pressure between two points in a system and show it on a single dial instrument. A magnetic movement senses the differential pressure. The instrument has separate pressure and indicating chambers. These diaphragm instruments can indicate small values of differential pressure even when used at high line pressures. These differential pressure instruments provide instantaneous and continuous information regarding system conditions helping in eliminating premature servicing of equipment, avoid unscheduled down time of costly processes and detect abnormal system conditions.

Switching Facility

Instruments can be supplied with reed switches to initiate alarms, activate other equipment, or shut the system down. Two switches are used when high and low limits are desired. Gauge-switch models provide the user with both, gauge readout and switch operation.


Monitor filter conditions, set filter by-pass, or initiate filter cleaning cycle. Check condition of pumps, heat exchangers, and other processing equipment. Detect abnormal and reverse flow conditions. Measure flow rates with venturi, orifice, or pitot tube.

  • Cost effective and reliable.
  • Uses diaphragm sensor.
  • Easy to read dial instrument eliminates the accumulated errors of two instrument installations.
  • Differential pressure range from 25mmto 600mmH O.
  • Working pressures 100 bar.
  • Indicating mechanism isolated from pressure chamber.
  • Wide applications in air, gas and liquid media.
  • Zero migration between high and low pressures.
  • Manufactured in ISO 9002 certified plant.
  • Exported worldwide.
Operating Principles

High and Low pressures are separated by a sensor assembly consisting of a magnet, diaphragm, and a range spring. The difference in pressure causes the sensor assembly to move in proportion to the change against a range spring.

A rotary magnet, located in a separate body cavity and isolated from the acting pressures, is rotated by magnetic coupling as per the linear movement of the sensor assembly. A pointer attached to the rotary magnet indicates differential pressure on the dial.

Switch: Reed switches are located adjacent to the pressure chamber and are activated by the magnetic field of the sensor assembly.

Technical Data
Ranges: 0-25 to 0-600 mm H O 2
Units of calibration: mm H O, mbar, IN H O, kPa. 2 2
Operating principle: Magnetic coupling with a convoluted diaphragm sensor.
Working pressure: 35 bar Accuracy : ± 2 % of FSD (Ascending)
Dial sizes: 3.5" (80mm), 4" (100mm), 4.5" (115mm) & 6"(150mm)
Body Material: Aluminium & SS-316.
Temperature: 80°C Max. for the media.
Protection: IP 65 for gauge
Migration of media: Zero migration between high and low pressures.
Connections: ¼" NPT(F) or ¼" BSP(F)(on request, longer lead time)
Wetted parts: Diaphragm, ceramic magnet, SS 304 spring, Aluminium or SS-316 as per the gauge body
Seals: Buna-N (Standard), Viton
Porting: In-line (Standard), Bottom or Back
Switch: One or two SPST or one SPDT. Switches are field adjustable. The set points can be increased or decreased externally with simple screwdriver adjustments. When two switches are used, either switch can be adjusted independently.
Dial case: Stainless steel case and flange.
Window: Glass (Standard), Acrylic, Toughened glass on request.
Other options: Dual scale, colour band.

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