Tubular heating elements

The production of closed tube elements in small and large quantities is a standard procedure for the REF. The tubular elements are filled completely automatically by our filling machines to a stretched length of approximately 3800 mm. They are subsequently rolled to a diameter of 8.5 mm, making it a compact and shock-resistant element. The next step is annealing, allowing the element to be bent into the most common shapes (see figure 5). The unheated zones are specified by the customer, but some standard lengths are available as well. The installation can be done using feed-through nipples or a flange plate, which is indicated by the customer. The electrical connection is by standard M4 connections, but a different version can be requested by the customer.

In addition to the custom made tubular heating elements, the REF has a basic stock of stretched tube elements in different lengths and power suitable for a connection voltage of 230 Volt. By applying stock elements, you significantly shorten the delivery time. The stock list can be found on the stock list link.

If you have any questions after reading this information, please contact us or submit a request.


The standard tube elements have an external diameter of 8.5 mm. The maximum length that we can produce by machine is approximately 3800 mm, but manually it is possible to produce up to a maximum of 6600 mm.

Composition of REF heating elements:

Standard tube material

Stainless steel 304, stainless steel 316, stainless steel 302b, SMO 254, Incoloy 800 and Incoloy 825.

Fill mass

The magnesium oxide we use provides high insulation resistance and a good heat transfer.

Heatin coil

Our internal heating coil is made of high-quality Nickel – Chrome quality 80/20.

Electric connections

M4 connections (standard), AMP 6.3 mm (sliding fastener), 2 connecting wires with silicone sheathing, 2 connecting wires with glass fiber spun sheathing or 2 PVC sealing bushes with connecting wires (PVC sheathing)*.

* Due to the watertight connection between the element and the connecting wires, PVC bushings with a diameter of more than 8.5 mm x 35 mm are placed on the element. This version is mainly used in the refrigeration industry and is resistant to a maximum of 70 degrees Celsius and with a maximum surface load of 2.0 W/cm2.


The element is sealed with silicone and a ceramic bush as standard.

Unheated area

The unheated zone at both ends can be made in standard 50 mm, 90 mm, 120 mm, 150 mm, 200 mm, 250 mm, 300 mm, 420 mm and 520 mm. If the desired length is not mentioned, we can produce it at an additional cost.

Installation options (standard)

Clamp nipples M12x10 mm / Solder nipples M12x12 mm

Clamp nipples M14x12 mm / Solder nipples M14x15 mm – M14x25 mm or M14x40 mm


It is possible to provide the tube heating elements with stainless steel ribs with a diameter of 28 mm. This version is intended to increase the heat transfer of the heating element in an air duct and thus achieve a higher efficiency.

Short delivery times

The production in our own factory is still the right choice, making us a fast solution with our short delivery times.

Guaranteed quality

We can guarantee the required quality by making annual investments in new machinery and the right knowledge.

Custom made elements

Your desired type of element is not mentioned on our website? No problem! We can design this for you or offer a suitable alternative.