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Vortex Flow and Vortex Meters for High-Temperature Process Elements with No Moving Parts

Quick Answer: Silver Automation Instruments supplies vortex flow meters for hot steam, gas, and liquid lines where process temperatures reach up to 400 °C. These meters have no moving parts, so maintenance is lower than with turbine or oval gear meters on hot lines. Send your pipe size (DN), fluid, temperature (°C), pressure (bar), and flow range for a fast quote.

Why Engineers Use Vortex Meters on Hot Process Lines

A vortex flow meter uses a fixed bluff body inside the pipe. The bluff body sheds alternating vortices downstream. A sensor counts the vortex frequency. Flow velocity is proportional to that frequency. Because there are no bearings, no gears, and no rotating seals, the meter does not jam when thermal oil or steam runs at 250 °C or higher. We have seen failures on customer sites many times. A chemical plant in Thailand replaced three turbine meters on a 280 °C hot oil loop with one DN50 vortex meter. The maintenance team stopped doing monthly bearing checks.

High-temperature designs add two things. A sensor neck extension moves the electronics away from the hot pipe. A remote mount option moves the transmitter up to 10 m away. The meter body includes PT100 temperature compensation. Combined with pressure input, the transmitter calculates mass flow for steam. In practice, most engineers skip the remote mount and then find the display housing too hot to touch. That is the wrong way to save money.

Materials and Temperature Ratings

Silver Instruments uses 316L stainless steel as the standard body for high-temperature vortex meters. Hastelloy C22 is available for corrosive hot fluids such as hot acid or chloride-rich water. The sensor can be piezo or capacitive depending on temperature and vibration. Capacitive sensors offer better low flow sensitivity on steam. Ceramic sensor options extend gas service up to 400 °C. Gasket selection matters. Spiral wound gaskets with graphite filler cover 400 °C service. PTFE gaskets fail above 230 °C. A desalination plant in Saudi Arabia used a Hastelloy C22 vortex meter on hot brine at 105 °C. The previous electromagnetic flow meter lost signal due to low conductivity.

Outputs and Accuracy Data

Standard output is 4-20 mA HART. Pulse output and RS485 Modbus RTU are optional. Accuracy is typically ±1.0 percent of reading for liquids and ±1.5 percent for gas and steam. Turndown is 10:1 to 20:1 depending on line size and Reynolds number. Line sizes cover DN15 to DN300. Flange ratings include ANSI 150, ANSI 300, and ANSI 600. For steam at 12 bar and 250 °C, a DN80 meter handles about 120 to 1200 kg/h. That sizing range changes with pressure and superheat. Do not copy a steam table example for saturated steam if your process runs superheated steam.

Installation Rules for High-Temperature Vortex Meters

Straight run requirements are 15D upstream and 5D downstream. Vertical mounting is preferred for steam. If the meter is horizontal, keep the sensor to the side. Condensate pooling on the sensor causes signal noise during startup. A water treatment plant in Vietnam saw erratic readings on a 200 °C steam line. The meter was installed after a reducing elbow with only 7D straight run. Moving the meter to a vertical line with 20D straight run fixed the issue.

Do not install a vortex meter directly after a control valve or pressure reducing station. The valve sheds its own turbulence. For hot gas service, insert a straightening vane if you cannot reach 15D upstream. Remote electronics should be mounted below the pipe to reduce heat rise. Use cable rated for 105 °C or higher between sensor and transmitter.

Recommended High-Temperature Vortex Meter Models

Silver Instruments model VXH-HT covers DN15 to DN150 in inline configuration. Model VXH-HT handles process temperat