Model HRW

Refractory Protective Well

The Delta Controls Model HRW Refractory Well is designed to protect the thermocouple element well from physical damage along with protecting the reactor nozzle and shell from the hot gas convection inside the reactor.  The HRW is placed in a hole through the refractory lining in the base of the thermocouple nozzle on the Claus Thermal Reactor.


  • Protects the thermocouple in Claus thermal reactors and incinerators
  • Prevents high temperature reaction gas convection into the nozzle
  • Prevents refractory shifting, spalling and expansion from damaging the element protective well
  • Selected fabrication methods improve performance and extend life of the HRW and thermocouple
  • Withstands thermal shocks
  • Formulated material blends provide enhanced resistance to corrosion, temperature and thermal shock
  • Provides refractory to nozzle/shell decoupling and allows non-damaging movement between the two


Cutaway View of Model HRW 1 Installed in a Claus Thermal Reactor, ANSI 4" and Larger Flange Sizes or mm Equivilant

Model HRW1

  • Service: For general-purpose refractory protection
  • Attributes: Good mechanical strength, very good for thermal shock, good at high temperature
  • Temperature: 2800°F (1550°C) continuous 2900°F (1600°C) intermittent
  • Material: Alumina blended with shock resisting agents
  • Insertion “B”: 100 inches (2500mm) maximum
  • Well O.D.: 2.0” (51mm)

Model HRW2

  • Service: For very high temp. refractory protection
  • Attributes: Excellent mechanical strength, fair for thermal shock, excellent at high temperature
  • Temperature: 3000°F (1650°C) continuous 3200°F (1750°C) intermittent
  • Material: Alumina blend; re-crystalized
  • Insertion “B”: 70 inches (1770mm) maximum
  • Well O.D.: 2.0” (51mm)

Model HRWZ

  • Service: Difficult and unusual applications
  • Temperature: To 4000°F (2200°C) maximum


The Delta Controls Model HRW protective well is placed in a hole through the refractory lining of a Claus Thermal Reactor. The HRW's purpose is to prevent damage to the thermocouple element protective well. The HRW also acts to prevent thermal shock damage to the element protective well by shielding it from relatively cold gases, such as are produced by steam quenching. However, the crystalline high-density element protective well cannot withstand rapid temperature changes. Cracks due to thermal shock can occur which may result in early thermowell failure.

Several material formulations are offered. Each one enhances various physical characteristics of the thermowell. This provides long life and optimal performance in specific reactors. The various blends are formulated for characteristics of mechanical strength, resistance to thermal shock, and the ability to withstand very high temperatures.


Additional Information


Refractory Protective Well

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