• ATEX certificate D-8640
  • ATEX certificate D-8660
  • ATEX certificate D-8680

Explosion Proof Immersion Heaters type D-8640/D-8660/D-8680 with retractable ceramic heating element

For hazardous areas, Sinus Jevi has developed explosionproof Ex ’de’ heating equipment, designed and manufactured in accordance with EN-IEC 60079-0, EN-IEC 60079-1, EN 60079-7 and EN-IEC 60079-31 certified by the independent testing institute ISSeP. The certificates cover zone 1 and zone 2 for hazardous areas.
Gas groups II A, II B and II C and temperature classes T6-T1. Dust group Ex tb zone 21.

The flame-proof (d) enclosures have been designed for non save areas to protect the environment against gas-explosions, caused by sparking by electrical connections of the heating elements and control devices. Several types of enclosures for immersion heaters, flanged or screwed, have been described on the next pages.
Each type covers a range of a maximum number of installed hairpin shaped heating elements and giving a range of installed capacities.
The screwed types for dimensions up to 3”.
The terminal enclosures have a IP66 degree of protection.
Standard the enclosure is coated with two layers, a zinc silicate primer and a top coating. Other coatingsystems on request.

All heaters are standard internal wired on terminals.

The maximum temperature for the terminal enclosure during operation is 80°C (based on maximum 50°C ambient temperature).
If cable entry exceeds 70°C, high temperature cables must be used. The required minimum distance between enclosure and connection flange, to ensure the temperature limit of 80°C in the enclosure, is listed in the following table as a function of temperature classes.
Maximum number of cable entries: 2 pcs M25/M20

Marking ATEX Ex II 2 G D
Ex d IIC T6-T1 Gb EN/IEC 60079-1
Ex tb IIIC T110°C Db EN/IEC 60079-31

Temperature class Distance enclosure to heater
T6 85°C 50 mm
T5 100°C 75 mm
T4 135°C 100 mm
T3 200°C 150 mm
T2 300°C 200 mm
T1 450°C 250 mm



Suitable for heating of fluids both liquids and gases and also solids. The heater consists of a certified flameproof enclosure
D-8640, containing:
– certified electric heating elements (Ex e II) ceramic or cartridge heating elements.
– one manually protective thermostat with manual reset or one thermocouple or pt100 as a safety device. Thermocouple and pt100 are only applicable in combination with an external temperature controller executed with a manual reset.
– threaded holes for cable entries and/or plugs of a certified flameproof model Ex d II B or Ex d II C.

The flame-proof enclosure has been built up out of a seamless body, a top cover and base plate. Each cover and base plate has been provided with 6 screw thread windings with a total length of 18 mm. The connection length of the threaded joint between cover or base plate and body should always be 5 thread windings minimum. The cover has been locked with an M4 screw and the base plate with an M6 screw. In the base plate of the enclosure spacer tubes can be welded in which the heating elements are brazed or welded.


Technical Specification

– Cartridge heating elements of Ø12.5 mm up to including Ø31.5 mm can be applied, also    ceramic elements from Ø26 mm up to including Ø46 mm.
– Material of the enclosure: carbon, low alloy steel, or ferrous steel.
– Material of heating elements: stainless steels AISI 304, AISI 321, AISI 316, AISI 904L, Inconel 600, Incoloy 800, Incoloy 825, Titanium, SMO, Copper alloy or Nickel alloy.
– Degree of protection of the enclosure: IP66.
– The maximum allowable energy-dissipation of the heating elements has been based on a maximum Watt density, determined by the temperature class, type of medium and process
The temperature setting of the thermostat, thermocouple or pt100, as stated in the EC type
Examination Certificate, is applicable only for heaters immersed into a hazardous fluid flow.

If the heater has not been immersed into a hazardous fluid but forms a part of an apparatus located in a hazardous zone, the temperature setting has to prevent the maximum temperature of the outside of the apparatus to exceed the temperature according to the temperature classification.


Certificate number ISSeP 08ATEX009X for heaters in zone 1 & 2 and gas group IIC
Certificate number ISSeP 10ATEX039X for heaters in zone 1 & 2 and gas group IIC

Types of this product

Flame-proof immersion heaters with retractable ceramic core elements.
Single or multi core heaters. For horizontal installation (vertical installation available on request).
The ceramic core elements can be withdrawn for inspection or replacement without having to drain the system.

– Ambient temperature -30°C – +50°C (-50°C … +50°C on request)
– The maximum allowable voltage is 690 Volt.

Marking ATEX Ex II 2 G D
Ex d IIC T6-T1 Gb EN/IEC 60079-1
Ex tb IIIC T110°C Db EN/IEC 60079-31

The immersion heaters are available with flange connection as well as with a screw plug.