Flow Measurement Systems Technical Support

Primary Flow Signal offers technical support and training for Operators and Engineers for the most effective and economical flow measurement solutions.

Technical Questions

Our technical support team is available to assist you with any questions or problems you may have. Needing to change flows and run a new flow calc? Having issues on site? We will guide you through the process and help find a solution.

Supervision

Our highly qualified staff can assist and support commissioning, start-up and maintenance of all supplied products in order to provide immediate trouble-shooting, minimize downtime and assure correct installation of all Primary Flow Signal flow elements.

Maintenance

Primary Flow Signal can offer maintenance service on site for PFS products. This service includes surveys to identify any requirement for maintenance and recommend major or minor rehabilitation or replacement, where necessary.

Start-up on 72" Fabricated Sealed Meter System Technical Support. Industrial flow meter installation with multiple pipelines and gauges in a plant setting. Technician in safety gear inspecting and maintaining heavy-duty machinery in an industrial environment.

Troubleshooting

Problem Potential Cause Corrective Action
Low or No output Primary Element Check the installation and condition of primary element depending on what type of DP device is being used.  Contact PFS once you have information on the device and we can provide a complete inspection process for you to follow.Check for sufficient upstream straight length of pipe without change in direction, diameter, etc. 
Loop Wiring Check for adequate voltage to the transmitter.Check the mA rating of the power supply against the total current being drawn for all transmitters/devices being powered. 

Check for shorts and multiple grounds 

Check for proper polarity at the signal terminal 

Check loop impedance (should not exceed the specification for your plant) 

Check wire insulation to detect possible shorts to ground

Impulse Piping Ensure that the pressure connection is not reversed. Check for leaks or blockage. 

Check for entrapped gas in liquid service or entrapped liquid is gas service. 

Check for sediment or debris in the DP transmitter process flange. 

Ensure that blocking valves are fully open and that bypass valves are tightly dosed. 

Ensure that density of fluid in impulse piping is unchanged.

Sensing Element (transmitter sensor) The sensing element is not field repairable and must be replaced if found to be defective. Disassemble the transmitter and probe further (check your manufacturer’s manual for instructions on how to disassemble your transmitter)

Check for any obvious defects/damage such as dents or punctures in the diaphragms. At this point you may need to contact your manufacturer if there are any defects in the sensing element.

DP transmitter does not calibrate properly Pressure source / source connections Check for restrictions or leaks in the calibrator connections. Check for proper leveling or zeroing of the pressure source. 

Check to see if temperature change has affected the pressure readings.

Check weights/gauge to ensure proper pressure setting. 

Determine if your pressure calibrator has sufficient accuracy

Meter Determine if the transmitter & calibrator are functioning properly
Power Supply Check the power supply output voltage at transmitter
DP Transmitter Electronics Make sure the transmitter connectors are clean. Check the D/A (digital to analog) conversion by performing a D/A trim with a calibrated multimeter in series with the field wiring.

If the electronics are still suspect, substitute with new electronics.

Sensing Element (transmitter sensor) The sensing element is not field repairable and must be replaced if found to be defective. Disassemble the transmitter and probe further (check your manufacturer’s manual for instructions on how to disassemble your transmitter) 

Check for any obvious defects/damage such as dents or punctures in the diaphragms. At this point you may need to contact your manufacturer if there are any defects in the sensing element.

High / Low Output Primary Element Check for restrictions at primary element
Impulse Piping Check for leaks or blockage. Check for entrapped gas in liquid service. 

Check for sediment or debris in the DP transmitter process flange. 

Ensure that blocking valves are fully open and that bypass or equalization valves are tightly closed. 

Ensure that density of fluid in impulse piping is unchanged.

Power Supply Check the power supply output voltage at transmitter
DP Transmitter Electronics For Flow application make sure square root extraction is applied once in the transmitter/PLC/SCADA etc. If the square root transfer function is not applied at all the flow reading will be lower than actual. If square root is applied twice the flow reading will be higher than actual.Make sure the transmitter connectors are dean. 

If the electronics are still suspect, substitute v1ith nev1 electronics

Sensing Element (transmitter sensor) The sensing element is not field repairable and must be replaced if found to be defective. Disassemble the transmitter and probe further (check your manufacturer’s manual for instructions on how to disassemble your transmitter)

Check for any obvious defects. At this point you may need to contact your manufacturer if there are any defects in the sensing element

Erratic Output Loop Wiring Check for adequate voltage to the transmitter. Check for intermittent shorts, open circuits and multiple grounds
Process Pulsation Adjust damping.
DP Transmitter Electronics Make sure the transmitter connectors are clean. If the electronics are still suspect, substitute with new electronics
Impulse Piping Check for entrapped gas in liquid lines and for liquid in gas lines.

There are a number of “differential type” flow meters that all have the same benefits in terms of performance such as:

  1. No moving parts so no frictional wear.
  2. Interior profiles that can be field inspected to determine if there has been any change to the interior profile of the meter.
  3. 98% of the time there is a concern that the “flow meter” is not operating properly, it is not the primary element (venturi meter, wedge meter, orifice meter, etc), it is the secondary instrumentation (DP transmitter(s), recorder, SCADA system, etc).
  4. Because the function of a DP meter is to report 2 pressures, upstream high pressure and throat or downstream low pressure.  So, pressure reporting is the requirement thus there are taps (typically 2 but in some cases more)- if there is any impairment to the pressure sensation at the taps, there may be an issue with the secondary instrumentation having an accurate pressure signal to process and the possibility that there is a plugged tap becomes greater.  Contact PFS for further help should this appear to be a problem.

Over the past 125 years, a number of different types of DP devices have been sold throughout the world and some of them have unique internal configurations and profiles that may have an impact on the production of an accurate pressure at the high and low tap points. 

Contact Primary Flow Signal with information as to the manufacture and model number in order for us to provide additional guidance.