Threaded immersion electric heaters are the optimal and economical solution to meet the heating needs of various process fluids, for all application sectors, rubber and plastic, civil and industrial. They facilitate the maintenance of the systems thanks to their easy replacement.

The heat is generated by the standard tubular heater in contact with the fluid to be heated and released during its operation when the heater is powered. 

This type of heater is designed to be inserted on threaded connections welded directly on pressure tanks or storage tanks in direct contact with the fluid to be heated. Thanks to this feature, it is possible to make heaters with high power and small dimensions, with an effective heat exchange.

According to the conditions of use defined by the customer (type of fluid to be heated, operating temperature, available dimensions and operating pressure) of the immersion heater, all the useful and necessary characteristics for defining the product are pre-established by the technical office to ensure long service life and quality of the product.

General characteristics of Threaded Electric Heaters.

Electric heaters can be ordered in single-phase or three-phase executions depending on the type of power supply available.

Immersion heaters consist of:

  • Threaded screw connection to be screwed onto the process welded sleeve
  • Heating elements
  • Any heat exchange splitters
  • IP40 ÷ IP65 electrical protection casing
  • Power and safety cable glands (if provided)
  • Regulation or safety thermostat
  • Ground connection

Materials and dimensions applicable to threaded immersion electric heaters.

All threaded connection immersion heaters are customized to the type of application and operating conditions. We can have:

Dimensione attacco filettato
Da ¾” gas- 1 ¼” gas -1 ¼” gas – 2” gas -2 ½ gas (disponibili anche in versione BSP, NPT)
Ottone - Acciaio inox 316L /304 – Titanio
Corazza Elemento riscaldante
Ø 8,5- Ø10- Ø15
Rame – Aisi 321 o 316L -Titanio – Incoloy 800 o 825
Filo resistivo
Varie sezioni
NiCr 80/20
Ossido di Magnesio MgO
Per tutti i diametri delle corazze
Grado “M”- Grado “HA” alte temperature
Custodia di protezione
IP40 o IP65
Makralon - Poliammide
Terminali di collegamento
Filettati o faston
Acciaio al carbonio o Aisi 304
Termostati ad asta rigida
Attacco faston per resistenze monofase
Asta in ottone
Termostato a bulbo capillare
Regolazione a riarmo automatico o sicurezza a riarmo manuale
Bulbo e capillare in rame o acciaio inox

For processes where the heater is used in highly corrosive environments, we recommend the use of special electrict heaterswith solutions more suitable for the type of application.

Two types of welding are used based on the manufacture materials chosen for making the immersion heater. For threaded connections in brass, silver-based brazing is used, while for threaded connections in stainless steel series 300 or Titanium, Tig welding is used.

Where requested by the customer it is possible to insert various types of thermostats to guarantee the proper functioning of the heater, for its service life and the customer’s system safety. It is possible to mount the following thermostat models on board the heater (also visible on the dedicated section “Instrumentations, Instruments, Instrumentations, accessories and spare parts” :

  • Single-phase regulation thermostats with automatic reset. Several adjustment scales including:
  1. Scale 4-40°
  2. Scale 30-90° C
  3. Scale 0-100°C
  4. Scale 50-300° C
  5. Scale 20-500° C
  • Single-phase manual reset safety thermostats with the following operating scales:
  1. Scale 0-150° C
  2. Scale 20-500° C
  • Single-phase safety thermostats with fixed setting and manual reset:
  1. 99° C calibration
  • Three-phase regulation thermostats with automatic reset:
  1. Scale 30-90° C
  • Thermostats with single-phase and three-phase regulation and safety:
  1. Manual reset adjustment 8-75° C manual reset safety 98° C.
  • thermostats for single-phase rigid rod heaters “RTR” model with automatic reset adjustment, scale 20-80° C.
  • thermostat for single-phase rigid rod heaters “RTD” model with automatic reset adjustment, scale 20-80° C and safety up to 92° C.

All thermostat models are with SP-DT changeover contact.

The electric immersion heaters on threaded connection are suitable for process temperatures up to 150° C and operating pressures of 15 bar.

With higher temperatures, special “cold head” return executions are implemented to protect the electrical enclosure of the heater connections, with relative regulation and/or safety thermostat.

Typical industrial applications

  • Water heating (pressurized storage tanks)
  • Oil heating in control units
  • Machinery for the food industry
  • Antifreeze systems for storage tanks
  • Fuel oil heating
  • Indirect heating

Special executions are also provided on request and customer specifications.

For any clarification, please contact Reart directly.