Model HRS

Refractory Stop, For Use with H-Series Drill Guide

The Delta Controls Model HRS Refractory Stop is used to prevent refractory castable or mortar from entering the thermocouple nozzle during lining of the reactor. After the refractory has cured, the HRS is removed and the refractory is drilled using the Delta Controls H6G drilling system.

Schematic of an HRS Installation

Model HRS Schematic of an HRS Installation

Model Numbering System

Model HRS Model Numbering System


  • Keeps refractory out of an HTP/HTX mounting nozzle during the reactor lining process
  • Produces a flat seat and the proper elevation for the HRW Refractory Protective Well to rest on.
  • Allows a diamond core bit to drill a correct hole through the refractory liner in a Claus Reactor.
  • Install in nozzle and tag before the refractory crew begins work
  • Used with all Delta Controls refractory drilling guide systems


  • Nozzle Flange Sizes: ANSI 2” 150 thru 6” 300, DIN 50mm thru 175mm
  • Disc Size: As required
  • Disc Insertion: As required, has ± 2” (50mm) adjustability
  • Disc Material: Nonstick PVC
  • Bar Material: 319 Aluminum
  • Insertion Rod Material: Plated Steel


The Delta Controls HRW refractory protective well must be located on the centerline and concentric with the Claus Reactor mounting nozzle. A hole is drilled through the refractory to accommodate the well. This hole must be located correctly if the well is to be in the proper position. The installed refractory face at the bottom of the mounting nozzle must be flat and at 90° to the centerline of the nozzle. The refractory drill bit can then easily start on the centerline of the nozzle. The resulting hole will be correct.

This refractory protective well is supported by the top face of the refractory. Excess refractory or mortar can easily enter the nozzle during the lining process, preventing the refractory protective well from seating properly or being at the correct vertical location. This can cause the thermocouple element well tip to encounter the refractory well bottom and be broken off during installation. The stop disc blocks the nozzle at the correct elevation and prevents refractory from entering the nozzle. The HRW is then supported at the correct elevation by the refractory face.

The Delta controls HRS refractory stop is bolted to the face of the flange on the mounting nozzle. A rod extends down into the nozzle and supports a flat disc at the bottom face of the reactor shell. This disc plugs the nozzle hole and is at 90° to the centerline of the nozzle. The HRS produces the surface conditions and location results detailed above; enabling a correct hole to be produced through the refractory.

The HRS is installed in the nozzle before the refractory installation begins. It is tagged to prevent inadvertent removal or adjustment by the refractory installation.

You can view the video below illustrating the use of the HRS Refractory Stop in a thermocouple Installation.

Additional Information


Refractory Stop, For Use with H-Series Drill Guide

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