Retractable Thermocouples

Figure 1

The Retractable Thermocouple System by John Zink Company provides the long awaited thermocouple-access solution. John Zink's revolutionary Retractable Thermocouple System allows operators to safely access thermocouples at grade while the flare remains in operation.

In instances where pilot detection is dependent on a thermocouple, it is imperative the thermocouple remain operational at all times. In the event a thermocouple failure occurs, the innovative John Zink^® Retractable Thermocouple System provides a means to replace the thermocouple while the flare remains in operation.

What does a Retractable Thermocouple System look like?

Figure 2

A sketch of a single Retractable Thermocouple System is shown in figure 2. Each thermocouple is contained in stainless steel tubing that runs the height of the stack. The thermocouple tubing is banded together and supported regularly at supports attached to the stack. The tubing is routed with long radius bends to allow the thermocouple to travel freely within the tube.

How does a Retractable Thermocouple System work?

The thermocouple is inserted into the tubing connection near grade. Then the thermocouple is pushed into the tube until the thermocouple is seated in the thermowell. Once the thermocouple is seated, the thermocouple is wired and attached to the thermocouple junction box. To lower the thermocouple, perform the procedure in reverse.

Does the thermocouple travel freely?

John Zink's unique Retractable Thermocouple System design is a direct result of many years of experimentation and development. Because the thermocouple travels freely up the tubing, the design has proven to be reliable and practical for plant operation.

Figure 3

Figure 4

Does the thermocouple twist and bend?

John Zink recommends that users purchase or rent a straightener. The straightener ensures the thermocouple travels freely during installation.

Can the thermocouple be pushed manually?

The thermocouple can be pushed manually for about 250 ft of the stack height. When manual pushing is no longer practical or desirable, a pusher can be purchased. The pusher is a mechanical device that pushes the thermocouple up the tubing into the thermowell. It is easy to operate and is powered by compressed air.

Contact a John Zink representative for more Retractable Thermocouple System information.

John Zink Company, LLC
11920 East Apache
Tulsa, OK 74116
United States of America
+1-918-234-1800

email: info@johnzink.com