by Bohuslav Bobrik Bohuslav Bobrik

Clamp-On Ultrasonic Flowmeters Ensure Reliable Measurement of Hot Liquids with Solids

APPLICATION NOTE
Chemical production plant at dusk

Clamp-On Ultrasonic Flowmeters Ensure Reliable Measurement of Hot Liquids with Solids

Summary

Zhejiang Xinhecheng Co., Ltd., founded in 1999, manufactures functional chemicals including nutritional ingredients, fragrances and polymer materials. For a trial project, the customer needed to measure a liquid containing 10% metallic solid particles at an operating temperature of 150°C. Traditional electromagnetic and differential-pressure flowmeters proved unsuitable because electrodes and primary elements were quickly worn down by the solid particles, requiring frequent maintenance, causing unplanned shutdowns and reduced yield. Clamp-on ultrasonic technology stood out because it can be installed externally without modifying the pipe or interrupting the process.

Application

Fig. 1: C-PT 1 MHz clamp-on transducer installed on a 2″ stainless steel line carrying the hot liquid catalyst.

MediumLiquid catalyst
Pipe size and thicknessDN50 (2″)
Pipe materialSS 304
Pressure0.2 MPa (29 psig)
Flow rate5 – 30 m³/h (22 – 132 GPM)
TemperatureUp to 175°C (347°F)
Requested accuracy±1-2% of reading
Panametrics

Benefits:

  • Low to zero maintenance
  • No pressure drop
  • No process interruption
  • High reliability and long term stability

Challenge

Interrupting production was not feasible, so the operator required a solution that could be implemented without disrupting ongoing operations. As there was no prior experience with this specific application, a field test was conducted to confirm that the flowmeter could perform under the process conditions. Furthermore, the customer expected the clamp-on ultrasonic liquid flowmeter to require minimal maintenance by design.

Solution

Panametrics conducted the field test using a PT900 portable flowmeter with 1 MHz clamp-on transducers. The transducers were mounted on a vertical pipe (Fig. 1) with flow from bottom to top. As the pipe was insulated, the insulation was removed for the test, and installation took approximately 15 minutes. The customer assessed the meter accuracy by triggering the control valve and comparing the resulting changes in flow – the flowmeter responded as expected, with readings tracking the valve’s percentage opening. Satisfied with the results, the customer decided to purchase permanent clamp-on instrumentation: the XMT1000LC with C-PT 1 MHz transducers, with an initial plan for two units. The meters have now been in service for several years, continuing to meet expectations while reducing maintenance costs and improving production yield. For future installations, the customer plans to use C RS HT transducers rated up to 230°C.

C-PT 1 MHz clamp-on transducer installed on insulated 2-inch pipe

Panametrics PanaFlow LC clamp-on ultrasonic liquid flowmeter

Datasheet (PDF) Panametrics PanaFlow LC

Source: Panametrics Application Note PANA148AN (panametrics.com) — © Panametrics LLC. Localized and prepared by INTECH CONTROL, official Panametrics representative for Slovakia and Hungary.

by Bohuslav Bobrik Bohuslav Bobrik

Clamp-On Ultrasonic Flow Meters Enable Safe Measurement of High-Pressure Hydrogen Gas in Chemical Production

APPLICATION NOTE
Chemical plant producing 1,4-butanediol (BDO) with high-pressure hydrogen gas lines

Clamp-On Ultrasonic Flow Meters Enable Safe Measurement of High-Pressure Hydrogen Gas in Chemical Production

Summary

Sanwei New Materials, a Chinese chemical producer, manufactures 1,4-butanediol (BDO) – a key raw material for biodegradable plastics – using the Reppe process. In this process, hydrogen gas reacts with a copper-based catalyst to form 2-butyne-1,4-diol (BYD), which is then hydrogenated into BDO. Precisely controlling the hydrogen gas flow throughout the reaction is essential both for reaction efficiency and for keeping the finished BDO within specification. The plant operates several high-pressure hydrogen gas lines that needed a dependable flow measurement solution.

Application

Fig. 1: Panametrics clamp-on transducers installed on a high-pressure hydrogen gas line.

FluidHydrogen gas
Pipe sizeDN80 / DN100 (3″ / 4″), wall thickness 20 mm
Pipe materialCarbon steel
Process temperature60°C (140°F)
Pressure30 MPa (4,351 psig)
Density~19 kg/m³ (1.19 lb/ft³)
Flow velocity4.5 – 6.5 m/s (14.7 – 21.3 ft/s)
Panametrics

Benefits:

  • Safe – fully contactless
  • Low maintenance
  • Easy installation with no process interruption
  • No pressure drop
  • Long-term stability and drift-free performance
Panametrics clamp-on transducers installed on the hydrogen gas pipeline

Challenge

The plant traditionally measured hydrogen gas with orifice-plate meters, whose differential-pressure cells required frequent recalibration. Every recalibration meant halting the process – cutting production yield and exposing staff to serious safety risks, given hydrogen’s high operating pressure and low flammability limit. The customer needed a safer, drift-free alternative that would not interrupt operations.

Solution

Clamp-on ultrasonic flow meters have measured hydrogen gas for almost 30 years, but clamp-on technology is rarely used at such extreme pressures: hydrogen’s low density combined with very thick, high-pressure pipe walls creates acoustic conditions that typical clamp-on gas transducers cannot handle. Panametrics tested transducers at 200 kHz, 500 kHz and 1 MHz, and found that the C-RS-402 sensor operating at 1 MHz delivered accurate, reliable results. Applying damping material around the clamping fixture and polishing the pipe surface beneath the sensors further improved signal quality. The team installed a triple-traverse configuration and configured the Panametrics XMT1000LC clamp-on flow meter (part of the PanaFlow LC platform) for high-voltage operation, raising the signal-to-noise ratio to between 5:1 and 8:1. With stable readings established, the plant’s DCS could base its process control directly on the flow-meter data. Close cooperation between the Panametrics technology and local service teams delivered a solution that now gives Sanwei New Materials more accurate, reliable hydrogen gas measurement – improving both safety and productivity.

Triple-traverse transducer installation on the hydrogen gas line
C-RS-402 transducer and clamping fixture configuration diagram
Stable flow readings displayed on the plant's DCS screen

Panametrics PanaFlow LC clamp-on ultrasonic flow meter

Datasheet (PDF) Panametrics PanaFlow LC

Source: Panametrics Application Note PANA001AN (panametrics.com) — © Panametrics LLC. Localized and prepared by INTECH CONTROL, official Panametrics representative for Slovakia and Hungary.

by Bohuslav Bobrik Bohuslav Bobrik

How Panametrics Clamp-On Flow Meter Technology Delivered Accurate Measurements of High-Velocity Water Flow in a Penstock Pipeline

APPLICATION NOTE
Hydropower plant with penstock pipelines

How Panametrics Clamp-On Flow Meter Technology Delivered Accurate Measurements of High-Velocity Water Flow in a Penstock Pipeline

Summary

700-meter-long penstocks at a hydroelectric power plant in China had no flow measurement to assess the water turbine efficiency and to better control the power plant performance. To address this gap, the operator evaluated three flow measurement technologies: vortex, differential pressure, and ultrasonic transit time. Before making any decision, they required a technical evaluation and a potential field test.

Application

Fig. 1: C-RS 0.5MHz installed on DN700 pipe.

MediumWater
Pipe size and thicknessDN700 (32″)
Pipe materialStainless steel
Pressure0.2 MPa (29 psig)
Flow rate4-7 m³/s (63,401-110,952 GPM)
Temperature~ 25°C (77°F)
Requested accuracy± 1 to 2% of reading
Panametrics

Benefits:

  • Easy to install with no process shutdown
  • Very low maintenance
  • No pressure drop
  • Unrivalled large turndown ratio from low flow to high flow
  • Long term stability and drift characteristics
Panametrics XMT1000LC transmitter showing measured readings

Challenge

The customer’s objective was to install flowmeters on these lines with the understanding that flow velocities could exceed 15 m/s (49 ft/s). At the same time, minimizing pressure drop was critical due to the limited available head (pressure). Conventional technologies such as differential pressure devices and vortex meters were not suitable, as both introduce pressure losses and are unable to handle low-flow conditions due to inherent cut-off limitations. Ultrasonic flowmeters were ultimately pre-selected, given their ability to overcome these challenges. However, the originally trialed solution reached its upper operating limit, constrained by default factory settings that could not be overridden. As a result, an alternative solution needed to be investigated and evaluated.

Solution

The Panametrics PanaFlow LC clamp-on ultrasonic flowmeter was selected, configured as a single path XMTXP R05 in a 2-traverse set up. This configuration supports liquid flow velocities from 0.03 to 20 m/s (0.1 to 65.6 ft/s), making it well suited to the application. Installed at the same pipe location, the flowmeter immediately provided accurate measurements, confirming a flow velocity of 16.52 m/s (Fig. 2). The customer was very satisfied with PanaFlow LC’s performance, as it matched their expectations in full. It was able to better monitor the water turbine efficiency and make the needed improvements for increased efficiency. As a result, Panametrics is now established as the sole qualified flow measurement supplier on the penstock lines, with multiple PanaFlow LC flowmeters installed.

PanaFlow LC clamp-on sensor installed on DN700 pipe

Panametrics PanaFlow LC Clamp-On Ultrasonic Flowmeter

Datasheet (PDF) Panametrics PanaFlow LC

Source: Panametrics Application Note PANA153AN (panametrics.com) — © Panametrics LLC. Localized and prepared by INTECH CONTROL, the official Panametrics representative in Slovakia and Hungary.