Spirax Sarco Orifice Plate System 7 November, 2018 www.coulton.com

How they work.... Flow dp 7 November, 2018 www.coulton.com When a fluid flows through a restriction it creates a pressure drop . If the flow increases , the pressure drop increases, and the maximum pressure drop will occur at the maximum flowrate. The pressure drop will be zero when there is no flow. However at 50% of the flow, orifice plates do not produce 50% of the pressure drop. Or put another way , the differential pressure that is produced by an orifice plate is not linear to the flow rate. dp 7 November, 2018 www.coulton.com

Orifice calculations... The pressure drop across an orifice plate is used to derive the rate of flow using....................... BS 1042 ISO 5167 ASME MFC - 3M (1989) Flow = K dP 7 November, 2018 www.coulton.com

Orifice Plate Output Flow Error 1:1 Flow Error 2:1 7 November, 2018 If the DP transmitter makes an error in the measurement of the pressure drop, different errors in the flow reading will be produced dependent on which part of the meter range is being used. This error will be introduced even if the square root extraction is included in the transmitter. 7 November, 2018 www.coulton.com

Traditional M240G system 7 November, 2018 www.coulton.com

Pressure transmitters FCX-A/CII Silicon Sensor Dual Temperature Compensation Eprom 7 November, 2018 www.coulton.com

Pressure transmitters FCX-A/CII Both Types use Measuring cell with floating sensor Floating silicone sensor in the cell neck, to improove the static pressure, overload and temperature characteristics. Protection diaphragm in the cell body allows an overload pressure corresponding to the maximum static pressure without damage of the sensor. 7 November, 2018 www.coulton.com

Pressure transmitters FCX-A/CII Capacitance silicone sensor The micro machined silicone sensor is based on the capacitance measuring principle. Capacitance C1 & C2 change with applied differential pressure. Cell protected from temperature variation by silicon fabrication and minimmal physical size. Stress forces are balanced by floating cell design. 7 November, 2018 www.coulton.com

Pressure transmitters FCX-A/CII Matching Convolutions reduce volume Convolutions are machined on the body. Diaphragm is electron beam welded to the body Diaphragm is pressed to body. Benefits No damage on over pressure Improved Temperature Spec Reduced Stress 7 November, 2018 www.coulton.com

7 November, 2018 www.coulton.com The Spirax Sarco M410 Orifice plate package is supplied as a complete package, this ensures that all of the required components for each metering station are supplied together. The package is labeled to identify all of the components that are being supplied against each application. 7 November, 2018 www.coulton.com

ORIFICE PLATE FLOWMETERS Advantages: Low cost, especially on large sizes No need for recalibration Widely accepted Disadvantages: Poor turndown (4:1 typical) Long installations Subject to wear. 7 November, 2018 www.coulton.com