Product features

  • Steadily high insulation properties of the heaters (>100 GigaOhm)
  • High-temperature resistant pipe cover for operating temperatures of up to 700°C
  • Immersion depths of 150 – 2250mm
  • Easy assembly and low-maintenance operation
  • Design optimised according to the process (diameter, material, connection)
  • UL/CSA approval
  • Wide selection of standard designs with short delivery times

Area of application

  • Drinking water, circuit water, de-ionised water, cleaning baths, etc.
  • Lubricating oils, hydraulic oils, heat-transfer oils, degreasing baths, etc.
  • Vapour, saturated vapour
  • Air, nitrogen etc.


Screw-in type immersion heaters are versatile heaters, standing out by long service life and energy efficiency when properly used for the purpose intended and in a design adapted to the process.
Siekerkotte produces these heaters according to DIN 44.874 as well as to the factory standards of leading mechanical engineers and equipment manufacturers.
As heat source of the tubular heater (TH), a wound wire resistor is centrally embedded in a pipe in highly compressed magnesium oxide (MgO). Since the MgO is highly hygroscopic, the insulation resistance drops and thus the heat output over time. This is why Siekerkotte has developed a closure (< 120°C) that, even after years, still ensures insulation resistances of >100 GigaOhm. Depending on the application purpose, THs with diameters of 6.5, 8.5, 11.5 or 16 mm soldered or welded to G¾“ –G2 ½“ screw heads are used. The selection of the TH primarily depends on the surface load of the pipe during the heating of the medium, as well as on the voltage/current the system is to be operated with. Monitoring and control is carried out by mechanical temperature controllers and/or limiters or by electronic Pt100 or thermocouples.

We have been successfully engaged in electric heat technology for more than 25 years and have internationally developed and manufactured reference solutions for the chemical, mechanical and plant engineering industry.

Tubular heater
Diameter6.5mm; 8.5mm; 11.5mm; 16mm
Material1.4404; 1.4571; 1.4828; 1.4876; 2.4858
Immersion depth150mm - 2250mm
Unheated lengthby arrangement
Designs available
MaterialBrass; 1.4301; 1.4305; 1.4571
Diameter¾″-SW36; 1 ¼″-SW60; 1 ½″-SW60; 2″-SW70; 2 ½″-SW85
IP codeIP00 to IP69
Control / Monitoring
Temperature controller (1-pin or 3-pin)by arrangement
Temperature limiter (1-pin)by arrangement
Temperature controller + limiter (1-pin)by arrangement
Temperature controller/limiter combination (3-pin)30-85 °/110 °C; 30°-110 °/140 °C
by arrangement

  • Shape and size of the connection housing are basically determined by the control technology selected