Hot:21282013-08-27 01:08:41 From: FTD Automation Instruments
1. Flow meter Mounting
1.1 Choosing the mounting place
Choosing the place where negative pressure in the pipe is avoided.
Choosing the place where no motors, no transformers are nearby, powerful electromagnetic ware may generate electrical interference.
When measuring mixed-phase medium, the flow meters shouldn’t be mounted on some place where the mixed –phase is separating.
When the environment temperature is between -25 °C~ + 60 °C, direct sun shine is better to be avoided.
Mounting the place where is free from vibration or little vibration, if strong vibration is existed, fix support is required before and after of the flow meter.
Temperature humidity should be within 5% ~9%
Direct raining and immersion is avoided.
1.2 Requirement for the straight pipe: ( D is the inner diameter of the flow meter )
Electromagnetic flow meters have low requirement for the straight pipe before and after the flow meters, Flow resistance fittings such as 90° elbow ,T Fittings, reducers, full-open valve, etc should have the 5D distance from the axis of the electrodes (not plane of the sensors) ; 10D distance in the upstream is required if there is different opening valves(for example adjusting opening valve). Normally 3D straight pipe is required in the downstream of the flow meter.
See following figure:
When measuring mixed medium, mixed points should have 30D distance from the flow meter, see following picture
1.3 Mounting place and Fluids Direction
The Electromagnetic Flow meter can be horizontal, Vertical or slide mounted.
When horizontal mounting, the axis of the electrodes must be horizontal to avoid electrodes short time insulation generated from the bubble in the liquid, also avoid sediments covering electrodes. The sensor shouldn’t be mounted in the highest point to avoid air accumulation in the pipe.
When the flow meter is vertically mounted, the flow direction should be upwards, it can have following merits. When there is no flow or small flow , the heavy solids in the fluids are down and the fatty substances are up to be away from the electromagnetic flow meter electrodes area. When measuring particle-liquid two phase fluids, such as slurry, pulp , vertical mounting can avoid uneven abrasion from the sediments. As the picture shows. The measuring pipe should be filled with liquid and back pressure should be existed. To avoid negative pressure (damaging the liners), the electromagnetic flow meter shouldn’t mount in the inlet of the pump, outlet is recommended. When sliding mounting the flow meter, the flow meter should be mounted in the going-up pipe; When mounting the flow meter in the open discharging pipe, the meter should be mounted in lower place.
Control Valves and Stop Valves in the downstream (instead of upstream) of the sensors are recommends
Method of mounting the flow meter in the well
1. Inlet 2.Over flow pipe
7.Outlet 8. Drain outlet 9. Drain Valve
Edit by FTD Automation Instruments (www.ftdinstruments.com)