ZT-100TEG Water in TEG Monitors
Continuous inline water content measurement in triethylene glycol
Purpose-Built for Glycol Dehydration
The ZT-100TEG series is specifically designed for measuring water content in triethylene glycol (TEG) used in natural gas dehydration systems. Monitoring water loading in the glycol circuit is critical for maintaining dehydration efficiency and preventing off-spec gas at the outlet.
The ZT-100TEG provides continuous, real-time measurement of water concentration in both lean and rich TEG streams. By tracking glycol quality throughout the regeneration loop, operators can optimise reboiler performance, detect contaminant ingress, and ensure the glycol is regenerated to the required purity before recirculation.
Key Features
TEG-Optimised Sensing
Calibrated for the dielectric properties of triethylene glycol, providing accurate water content readings across the full operating range.
Hazardous Area Certified
ATEX and IECEx certification for Zone 1 and Zone 2 installations. Suitable for gas processing facilities.
Standard Communication
4-20mA analog output and Modbus RTU digital communication for integration with DCS, SCADA, and PLC systems.
Robust Construction
316L stainless steel wetted parts standard. IP67 rated enclosure for outdoor installations at gas plants.
Low Maintenance
No moving parts and no consumables. Solid-state sensing element with extended service life in glycol service.
Fast Response
Rapid measurement update rate for real-time monitoring of glycol quality changes during regeneration cycles.
Automatic Temperature Compensation
The dielectric constant of water drops significantly with temperature — from approximately 88 at 0°C to 48 at 100°C. Without compensation, a water content reading calibrated at ambient conditions would drift substantially at reboiler outlet temperatures. But temperature also affects the TEG phase: the dielectric constant of triethylene glycol changes with temperature as well.
Every ZT-100TEG includes an integrated process temperature sensor and firmware that compensates for both effects simultaneously. The water dielectric is corrected using a linear temperature model derived from published data. The TEG dielectric is corrected using a product-specific lookup table calibrated for triethylene glycol. These compensated values feed into a physics-based mixing model that calculates the true water content from the measured capacitance — regardless of process temperature.
This is particularly important in glycol dehydration systems where the lean glycol leaving the reboiler at over 200°C must be compared with the rich glycol returning from the contactor at much lower temperatures. Automatic temperature compensation ensures comparable readings at both measurement points.
Water Phase Correction
Dielectric constant modelled as a function of temperature. Compensates for the large permittivity change in water across the operating range.
TEG Phase Correction
Product-specific dielectric table calibrated for triethylene glycol, accounting for the temperature behaviour of the glycol medium.
Board Electronics Compensation
A separate compensation layer corrects for temperature-induced drift in the measurement electronics, normalised to a 25°C reference point.
Product Range
ZT-100TEG F-Series
Inline Measurement Spool
Full-bore flange-mounted monitor for TEG circulation lines. Available in 2", 3", 4", and 6" sizes with ANSI 150 and ANSI 300 pressure ratings.
- Full bore measurement across the pipe section
- ANSI 150RF and 300RF flanges
- Ideal for main glycol circulation loops
ZT-100TEG S-Series
Inline Measurement Spool
Compact threaded-connection monitor for glycol sample points and smaller process connections. Easy installation in existing tapping points.
- 1" and 1.5" NPT/BSP connections
- Compact form factor for tight installations
- Suitable for glycol skid and regeneration unit connections
ZT-100TEG I-Series Flanged
Flanged Insertion Probe
Permanently installed flanged insertion probe for high-pressure, large-diameter glycol lines. Simpler installation with higher pressure capability up to ANSI Class 1500.
- For pipelines 6" and larger
- Rated up to ANSI Class 1500
- No retraction kit required — compact and robust
ZT-100TEG I-Series Retractable
Retractable Insertion Probe
Hot-tappable insertion probe for large-diameter glycol lines. Install and remove under pressure using a full-bore ball valve and retraction kit. Up to ANSI Class 300.
- For pipelines 6" and larger
- Hot-tappable — install without shutdown
- Includes retraction kit with packing gland and guide tube
Applications
Lean Glycol Monitoring
Verify regenerated glycol purity before re-injection into the contactor. Ensure water content meets specification for effective gas dehydration.
Rich Glycol Monitoring
Track water loading in the rich glycol stream from the contactor to optimise regeneration reboiler duty and energy consumption.
Reboiler Performance
Monitor glycol quality before and after the reboiler to verify regeneration efficiency and detect degradation or contamination.
Glycol Make-Up Control
Detect glycol losses and contamination events that affect water content readings, triggering maintenance or glycol replacement.
Configure Your ZT-100TEG
Our engineering team can help you select the right configuration for your glycol dehydration system, including process connections, materials, and certifications.
