Model HTS


Thermocouple, Sulfur Processing Service, Compact

The Delta Controls Model HTS Thermocouple is designed for the primary purpose of reliably protecting a vessel and its refractory lining from excessive temperatures. The HTS is designed for installations unable to accommodate the recommended 6 inch process connection of the Model HTX. The HTS provides long term accuracy and reliability in sulfur processing service.

The design of the HTS is the result of attention to detail, more than 50 years of experience, and numerous field installations. The thermocouple junction is isolated from corrosive and invasive gases by using a constant 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 primary thermowell, body, or seals. Process gases that 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 Model HNP, consisting of ceramic fiber rings sized for the customer’s nozzle, is required with the use of the HTS.

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

The HTS is built to meet each customer’s specific installation requirements, such as thermocouple type, insertion length, and materials of construction.

Installation tools are available, and recommended to accurately produce the refractory borehole in the correct size and alignment needed by the refractory thermowell and HTS Thermocouple assembly.


  • Compact thermocouple utilizing verified technologyfor sulfur processing service
  • Worldwide 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 Material: Aluminum or 304 Stainless Steel
  • Element Well Material: Blended alumina ceramic
  • Threaded Process Connection: ANSI 1.5, 2.0 in MPT
  • Flanged Process Connection:ANSI 1.5 in, 2.0 in, 3.0 in(other sizes, types ratings available)
  • Flush Gas: Nitrogen (11 L/h)
  • Working Pressure: 150 psig (10.3 bar) at 500 °F (260 °C)
  • Working Temperature: 0 °F to 3100 °F (-18 °C to 1704 °C)
  • Required Accessories: Model HFS Flush Gas Station Model HNP Nozzle Packing Kit

Certifications & Approvals

  • Housing Third Party Listed by CSA NRTL/C (USA and Canada)
    Class I, Groups B, C and D;
    Class II, Groups E, F and G;
    Class III; Encl 4X

Required Ordering Information

  • Detailed model number
  • Tag or nameplate detail (if required)
  • Documentation & testing packages (if required)
  • Installation Details
    Nozzle inside diameter
    Shell thickness
    Nozzle inside height
    Refractory thickness
    Nozzle angle from vertical

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Thermocouple, Sulfur Processing Service, Compact

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