Pulsation Testing Equipment, Square Root - Gauge Line Error Indicators

Parker PGI’s SRE-6 and GLE-6 Series are square root and gauge line errors indicators. 

The heart of the SRE-6/GLE 6 system is a Windows-based software program designed for ease of operation.  

The system calculates the percentage of SRE and or percentage GLE, and displays a spectrum that shows what frequency the pulsations are occurring.  

The software then shows the annualized gas volume and estimated gas cost that could be incorrectly measured because of pulsations.  

In addition, the system will store the data to provide reports for future analysis.  

Additional features include: low and high pass filtering of data for easy of troubleshooting, advanced diagnosis strip chart of transducer(s) voltages, ability to modify test description without affecting test results, and legacy data upgrade. 

Most natural gas flow measurement in the United States is performed by measuring pressure drop at two points (pressure differential) induced by an orifice plate.  

The gas flow rate (Q) is calculated using the basic formula   Q = K/DPXP.  

The fixed orifice coefficient (K) is derived from a formula found in the latest edition of AGA Report Number 3.  

Differential pressure DP and line pressure P are measured either using mechanical chart recorders or electronic transmitters, remotely or direct mounted to the pressure taps, using a configuration of instrumentation valves, manifolds, and tubing. 

Percent Square Root Error (%SRE) is measured with a device manufactured and marketed by Parker PGI called the Square Root Error (SRE) Indicator.  

The indicator is used by field technicians to measure the severity and calculate %SRE.  

The %SRE is measured at operating conditions and is used to approximate the primary element error induced by pulsation and to determine whether corrective action is necessary. 

Parker developed its initial Gauge Line Error (GLE) in 1990, while our most current SRE/GLE Indicator includes the ability to perform both %SRE and GLE tests, thus measuring and quantifying both Square Root Error and Gauge Line Error. 

Gauge Line Error (GLE) exists when the differential pressure (DP) at the taps does not equal the differential pressure (DP) at the end of the gauge lines. GLE is typically caused by either pulsation or other flow phenomena. 

The GLE Indicator compares the differential pressure at the orifice taps with the differential pressure at the end of the gauge lines.  

Any difference between the two signals would be associated with gauge line error.