The main reason to measure the dew point of gas under pressure is to avoid the risk of condensation forming in the system, which can lead to bacterial growth or corrosion of valves. Condensation becomes a risk when gas is pressurized because the dew point of air or gas rises with pressure. This makes drying the air especially crucial and monitoring the dew point of the dry gas not only helps control drying cost but also provides quality checks on the high-pressure air or gas. Our article ‘How to calculate pressure dew points (PDP) accurately’ explains the physics that causes this.
In industrial applications, pressures from 20 to 450 barg (290 to 6527 psig) are referred to as ‘ultra-high pressures’. Typical applications for ultra-high-pressure air include:
Avoiding excess moisture is vital in marine applications because of the risk of freezing. Reducing the pressure of a gas has a cooling effect, and this, coupled with the already low temperatures below sea, could easily lead to ice forming in air lines and disable the submarine.
Metal oxide moisture sensors directly measure the partial pressure of water vapor. For any given partial pressure of water vapour there is only one corresponding dew point. This means that as the partial pressure of water vapour increases with total pressure, the measurement performance remains valid and directly related to its factory calibration.
The Michell Ceramic Metal Oxide moisture sensor has been designed with high-pressure applications in mind, providing excellent performance when compared to the performance of alternative polymer-sensor products.
The sensor is placed directly in the gas line and measures at line pressure.
Spot checks using a portable hygrometer.
A sample of gas is removed from the system and moisture is measured at a lower pressure.
We have a wide choice of dew-point transmitters and portable hygrometers that are capable of measuring dew point and trace moisture in gases at various pressures.
Measure trace moisture in pressures from 100 barg/1450 psig up to 138 barg/2002 psig
SF82 | Dew Point Control | Compressed Air Dryers (processsensing.com) - 100 barg/1450 psig
Portable Fast-Response Hygrometer - Michell MDM50 (processsensing.com) High-pressure version (HP): 100 barg/1450 psig
Process Moisture Analyzer - Michell Promet EExd (processsensing.com) - 30 to 138 barg /435 to 2002 psig
Moisture in Natural Gas Analyzer - Michell OptiPEAK TDL600 (processsensing.com) - inlet pressure max 100 barg/1450 psig
Hydrocarbon Dew-Point Analyzer | Automatic On-line Analysis (processsensing.com) for water dew point at 138 barg/2002 psig
Measure trace moisture at pressures up to 350 barg
Measure trace moisture at pressures up to 450 barg/6527 psig:
Michell Easidew EA2 | Moisture Meter (processsensing.com) - up to 450 barg/6527 psig For in-line measurements in ultra-high-pressure air. A hazardous area version is available for measurements in flammable gases, such as natural gas or biomethane.
Process Moisture Analyzer - Michell Promet I.S (processsensing.com) up to 450 barg/6527 psig A complete sampling system for measurements in natural gas or other flammable gases.
Measure trace moisture in air or gas up to 900 barg/10,153 psig
Moisture measurements in these pressures are possible with the Michell Ceramic Metal Oxide Moisture Sensor and Michell Easidew Dew-Point Transmitters range. Contact us to get expert advice for your project.
Sign up to one of our Industry newsletters and you’ll receive our most-recent related news and insights all directly to your inbox!Sign Up