Model HTS

Thermocouple, Claus Sulfur Recovery Service, Compact

The Delta Controls Model HTS is designed for the primary purpose of reliably protecting a vessel and its refractory lining from excessive temperatures. The HTS is designed for installations without the availability of the preferred larger process connections of the Model HTX. The HTS provides long-term accuracy and reliability in Claus thermal reactor service.

The design of the HTS is the result of attention to detail, 40 plus years of experience, and over 100 field installations. The thermocouple junction is isolated from the corrosive and invasive gases by using a constant very low flow flush gas circulating across the junction. The flush gas is kept at a pressure higher than the internal reactor pressure to mitigate the migration of process gases through the element well, body or seals. Process gases that do enter are carried away by the flush gas. The metered flush gas flow has an insignificant effect on the accuracy of the temperature measurement. The HTS is provided with a nozzle packing kit, the Model HNP, consisting of ceramic fiber rings sized for the customer’s nozzle.

For most applications, the Model HTX is preferred as it offers the highest reliability of any Claus Reactor thermocouple. The Model HTS provides a highly reliable alternative compatible with smaller process connections for installations unable to accommodate the recommended 6” process connection of the HTX.

The HTS is built to meet each customer’s specific installation requirements, such as; thermocouple type, operating temperatures, nozzle size, insertion length, and materials of construction. The HTS assembly is furnished complete with all necessary installation components. Installation tools are available, and recommended, to accurately produce the refractory bore hole in the correct size and alignment needed for the refractory well and thermocouple assembly.


  • Compact thermocouple utilizing verified technology for sulfur recovery service
  • Worldwide technology standard for protecting Claus thermal reactors
  • Maintenance free
  • Remains accurate under extreme conditions
  • Protects and extends the useful life of refractory and improves reactor up-time
  • The only proven thermocouple technology to function reliably long term in sulfur service


  • Thermocouple Types: B, R, S (others available)
  • Body Material: Stainless Steel
  • Trim, Bolting, and Seats: Stainless Steel
  • Housing: Aluminum or Stainless Steel
  • Element Well: Blended alumina ceramic
  • Process Connection: ANSI 1 1⁄4”, 1 1⁄2”, 2” NPTM, ANSI 1 1⁄2”, 2”, 3” RF Flange, Other sizes, types, ratings available
  • Flush Gas: Nitrogen (11LPH)
  • Certification: CL I Div 1 Group B,C,D Enclosure 4X (Housing)
  • Working Pressure: 150 PSIG (10 Bar) at vessel skin temperature of 500°F (260°C)
  • Working Temperature: 0 - 3100°F (1700°C)
  • Required Accessories: Model HFS Flush Gas Station, Model HNP Nozzle Packing Kit
  • Optional:
  • Refractory Drill Kit
  • Thermocouple extension lead wire
  • Refractory diamond drills and casting mandrels
  • Field training
  • Consultation and assistance

Additional Information


Thermocouple, Claus Sulfur Recovery Service, Compact

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