Multiple sensing ports of the CONTINUOUS PURGE FLOW METER system enable the operator to measure the average flow rate across the pipe section. The straight run requirement is normally as short as 5 times of pipe diameters of upstream and 2 times of pipe diameter of downstream (Dependent on the upstream conditions).
Flow straightener reduce the length of the straight run as same length of pipe diameters of upstream and same length of pipe diameter (Dependent on the upstream conditions).

The Composite Pitot Tube is under constant back pressure (air purged), due to the continuous air supply from
the Precision Differential Pressure Transmitter (continuous air purging).
This prevents dust, mist and fume from entering into the Pitot Tubes, eliminating corrosion of the Pitot tubes.

The Precision Differential Pressure Transmitter achieves the measurement of an extra-low differential pressure (25 Pa F. S.) which converted to flow speed of 1.4 m/sec. (at normal pressure and temperature in air basis).

The standard materials (316L Stainless Steel) permits measurement at a temperature up to 500°C.

Applicable to both circular and rectangular pipes and ducts.

Instrumented air with a pressure between 0.3 and 0.8 MPaG is supplied to the Air Supply Set, where the pressure is regulated to 0.14 MPaG.
Precision Differential Pressure Transmitter controls the purging air flow for Pitot Tubes.
Purged air flow rate is not effected by the variation of the static pressure changes in the process (constant purge of air to the high and low sensing ports of the Pitot Tubes).
These constant purging for High and Low port generates back pressure against the gas stream in the process, then a differential pressure produced to differential pressure transmitter in the Precision Differential Pressure Transmitter.

The manifold valve enables zeroing of Precision Differential Pressure Transmitter without stopping the air purge during continuous operation. The connecting tubing pressure losses are cancelled while zeroing.

This is designed to regulate the pressure of instrumented air, removing moisture and oil mist before supplying to the Precision Differential Pressure Transmitter.

Purge Set controls the purging air flow for pitot tubes. Purged air flow rate is not affected by the variation of the static pressure changes in the process (constant purge of air to the high and low sensing ports of the Pitot Tubes).
These constant purging for High and Low port generates back pressure against the gas stream in the process, then a differential pressure produced to Differential Pressure Transmitter which connected outside on the Purge Set.

The Automatic Blow System can be combined with a Composite Pitot Tube or Barflow Tube. Forced blowing is carried out for a predetermined duration at predetermined intervals using a microcomputer-controlled timer, which saves the time and labor of manual blowing. It can also be controlled from the DCS side. This can be incorporated in the control panel together with the motor-driven valve. Contact JMS for other combinations.