Differential Pressure Transmitters

Differential Pressure Transmitters

Chilled water pressure has always been an important parameter, both for monitoring and for control purposes.

Monitoring the pressure at critical points in the piping network allows for early preventive maintenance. Controlling the pressure allows for flow regulation and system balancing.

However, the value of the pressure itself is not as useful as the difference in pressure.

Differential pressure transmitters, also called DPT, measure the pressure difference between two points and transmit a signal to the controle module.

DPT's are made up of a housing containing a primary element, a secondary element and an electronic device.

The primary element presents an obstruction or a contraction, thus causing a pressure drop before and after. Orifice plates, venturi tubes and pitot tubes are widely used in DPT's as the primary elements.

The secondary element is what measures this pressure drop and sends it to the electronic device as an electric signal. This could be a capacitor or a resistor that changes its properties based on the pressure drop.

Where to install DPT's?

1. Across pumps

2. Across most hydraulically remote unit

3. Between supply and return pipes of branches

Comments

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