TVA Flowmeter for Saturated Steam Service
The Spirax-Sarco flow meter TVA is designed for use with saturated and superheated steam.
The operating principle is based on measuring the force exerted by a moving cone. The movement of the cone is caused by the flow of the medium. This force is converted into a density-compensated mass flow rate, translated into a 4-20 mA signal, and a pulse output. The TVA also includes a total flow rate function and an EAI 232C (RS232) or EAI 485C (RS485) Modbus communication.
Diameters and Connections:
DN50, DN80 & DN100
The TVA is a sandwich model, suitable for installation between flanges:
- EN 1092 PN16, PN25 & PN40
- ASME B 16.5 class 150 & 300
- BS 10 Table H, JIS20, KS20
Note:
The TVA should be installed in pipelines according to BS 1600, ASME B 36.10 Schedule 40, or EN 10216-2 / EN 10216-5 equivalent. Consult Spirax-Sarco if other standards are used.
Pressure and temperature limits:
see datasheet
Accuracy:
The Spirax-Sarco flow meter TVA has built-in electronics that provide an output signal proportional to the density-compensated mass flow rate. The electronic housing contains an LCD display. A digital display type M750 can be provided for remote reading via the 4-20 mA output, if desired.
System accuracy, with 95% reliability (2 STD) (according to ISO 17025):
- 2% of the measured value at a flow rate between 10% and 100% of the maximum flow rate.
- 0.2% FSD at a flow rate between 2% and 10% of the maximum flow rate.
Measurement ratio:
up to 50:1
The stated inaccuracy of the TVA is valid for the complete system. Many flow meters state the inaccuracy of the element in the pipeline. To know the inaccuracy of the complete system, you need to add the inaccuracy of the peripheral equipment, such as DP transmitters.
Pressure Drop:
The pressure drop across the TVA is nominally 750 mbar at maximum flow rate for a TVA DN50 and 500 mbar if it is a DN80 and DN100.
