Averaging Pitot TubesOverview
Pitotbars are installed in power stations, petrochemical and chemical plants, pollution control applications, water treatment plant, refineries and steel plants. Averaging pitot tubes can be inserted in to pipelines under pressure (hot tap and retractable under pressure) to measure a wide range of fluids. These range from super heated steam, saturated steam, boiler feed water, bio gas (biogas), Syngas, dirty gas flows, stack gas for emissions monitoring and others. We can supply purge systems including constant positive air supply purge pressure systems to ensure particulates do not enter the impact / dynamic pressure ports of the pitot. The port holes have different sizes depending on the model, for gases liable to condensation, large pressure ports are required to prevent water column forming in the impulse lines and pressure channels.
The PITOBAR Averaging Pitot tube principle of operation is derived from the classic or single point pitot tube, which has been used in industry for many decades.
The single point pitot tube is manually moved up and down the pipe or duct to measure the flow (dynamic pressure). The PITOBAR averaging pitot tube has a number of holes depending on the pipe size pointing towards the upstream side. Generally one port points downstream to measure the static pressure, however where we require bi directional measurement, we ensure the upstream and downstream ports are replicated on both sides of the sensor, providing full bi-directionality. The transmitters can be ranged accordingly (-100% to +100% = 4=20mA, 12 mA=0 flow) or we can stack transmitters with the +/- sides of the transmitters reversed to give full rangability. For wide flow ranges we have our multi range transmitters offering 400:1 turndown, reducing the number of transmitters required.
The fluid must be single phase and the pipe must be full in the measurement section. Changes in flow rate must be slow and non pulsing.
The PITOBAR has a low installation cost, and the pressure loss is low compared to other flow elements, especially in large pipe sizes.