Steam flow measurement

There are many instruments for measuring steam flow. In the past, people preferred orifice plate differential pressure flow meters, but due to the significant and irreversible pressure loss associated with orifice plates, and considering that steam is becoming increasingly valuable, it is not cost-effective to allow steam to be wasted as a result of measurement errors. The following principles should be followed when selecting steam meters: low pressure loss, easy installation, and appropriate measurement accuracy. Because **there are currently no specific methods for testing and calibrating steam meters, making it impossible to carry out comprehensive calibration; therefore, there is no need to pursue high precision.** Vernier, Pitot tubes (constant velocity tubes), vortex flow meters, mass flow meters, etc., are all quite suitable. I am particularly optimistic about Pitot tube systems – they are easy to install, cause minimal pressure loss, and can be used with intelligent differential pressure transmitters as well as intelligent integrators (with pressure compensation for saturated steam, and temperature and pressure compensation for superheated steam).

Measuring the vapor flow rate is indeed a rather challenging task. In the past, users employed differential pressure flow meters for this purpose, but the results were not very satisfactory and maintenance was required frequently. Later, target flow meters with compensation mechanisms were used, and the results were better, though accuracy still needed further improvement; however, almost no maintenance was needed anymore, so process control was not an issue at all. Regarding flowmeters, different people have different opinions; the choice should be made based on specific circumstances.

For measuring steam flow, orifice plate flow meters are quite good options; they generally do not suffer from major failures, and their maintenance is simple. If a failure occurs within the meter itself, it is usually due to blockages in the positive or negative pressure sides or in the pressure guiding tubes, and this can be resolved by clearing such blockages. The zero point can be adjusted by everyone