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Explosion-proof Shells SMD MK (Ex-component)

The SMD MK shell is an Ex-component in accordance with GOST IEC 60079-1-2011 and is intended for further development of the housing, equipment installation and manufacture of explosion-proof products on the basis of this shell. A shell that has a certificate for an Ex-component can be considered as equipment for obtaining a certificate and makes it possible not to pass all type tests of an empty flameproof enclosure. In coordination with the manufacturer, the shell can perform the functions of connection (branching) of general-purpose and special-purpose electrical circuits (power circuits, control circuits, alarms, etc.) in hazardous areas with Ex d IIB U / Ex tb IIIB U explosion-proof markings. are electrical equipment of group III, designed for use in places hazardous for explosive dust environments, subgroup IIIB (non-conductive dust), IIIА (combustible volatile particles).

According to GOST 60079-1-2011, rotating machines or other devices that create turbulence, including oil-filled circuit breakers, are not allowed to be installed inside the shell.

The casing is designed to operate at an ambient temperature of minus 60 to plus 85 ° C, and a relative humidity of 90% at a temperature of 40 ° C without moisture condensation. The degree of protection against dust and moisture penetration in accordance with GOST 14254 IP66. Type of climatic design UHL1 according to GOST 15150-69, type II atmosphere according to GOST 15150. Altitude not more than 4300m above sea level. The enclosure material is made of stainless or aluminum alloy with a total content of magnesium, titanium, zirconium and not more than 7.5%.

The explosion-proof casing of the SMD MK allows manufacturing explosion-proof switching boxes and explosion-proof posts at its base. The SMD MK jacket can be equipped with explosion-proof cable glands of the KV TU 344995-138-81888935-2016 series produced by “SMD Company LLC”. Connecting thread cable entries G1 / 2, G3 / 4, M32, M40 and M50, their maximum number depends on the dimensions of the housing. Entries in the equipment are mounted with the calculation of the convenient location of the wrench head in accordance with GOST 13682-80. Cable entries allow you to enter and output cables with a maximum cross section of 42 mm.

Explosion-proof cable glands have different designs:

  • for open laying of the attached cable;
  • for laying of the attached cable in a pipe;
  • for connecting an armored cable;
  • to connect the cable in the metal hose RZTSH;
  • for connecting a double-sealed armored cable.

The type, number and location of cable entries are indicated when ordering. Each cable gland includes rubber cable seals..

The service life of the shell to write off - 10 years.

Explosion-proof shell SMD MK Ex-component is manufactured as standard. The shell does not have in its design of internal or external equipment. The manufacturer and the customer, if necessary, determine the number and location of openings for HF, switching and display elements. The customer, using the Ex-component for the manufacture of the final explosion-proof equipment, can independently drill holes and cut threads in accordance with the manufacturer’s specifications and GOST IEC 60079-1-2011.

1 2

1. - name of explosion-proof shell “SMD MK” Ex-component;

2. - modification.

The design should provide the possibility of using the product in hazardous areas and in rooms 1 and 2 of class according to GOST IEC 60079-10-1-2011 and GOST IEC 60079-14-2011;

The shell has a simple geometric shape with permissible deviations for a narrowing of not more than 10%;

In the case of explosion-proof shell there are special places for installation and assembly of internal components.;

Inside the shell, the customer can place the terminal clamps, power circuits, control circuits, alarms, etc. During installation, it is necessary to leave at least 20% of the cross-sectional area of the shell free to allow the gas flow to flow unhindered, so as not to limit the development of the explosion;

Depending on the application conditions, holes are drilled in the shell for mounting cable entries, buttons, indicator lights, etc .;

Third parties using the casing to design explosion-proof equipment are not entitled to drill holes in it at their discretion;

Any openings that are permissible in accordance with the certificate for the shell of the Ex component can be made by the manufacturer of the shell of the Ex component or by agreement between the equipment manufacturer and the manufacturer of the shell of the Ex component;

The envelope is completed with explosion-proof cable entries, for example, the KV series TU 344995-138-81888935-2016 produced by “SMD Company”.

According to GOST IEC 60079-1-2011 p. 5.3, the thread must form an explosion-proof connection.

On the case there should be a sign indicating the marking of explosion protection and the necessary warning labels;

Outside the case is a grounding clamp. A grounding clamp must provide a ground wire connection with a cross section of at least 4mm2;

The SMD MK enclosure is provided with an explosion proof type of “explosion proof enclosure “ d” according to GOST R GOST 31610.0-2014, GOST IEC 60079-1-2011 and are marked Ex d IIB U / Ex tb IIIB U.

The SMD MK shell belongs to Group II electrical equipment and is intended for use in places (except for underground mines and their ground structures) hazardous in explosive gas environments in accordance with the explosive category of the mixture (subgroup IIB - ethylene and IIA - propane), and is also electrical equipment of group III for use in locations hazardous for explosive dust environments, subgroup IIIB (non-conductive dust), IIIA (combustible volatile particles).

The shell corresponds to a high degree of mechanical strength according to GOST 31610.0-2014.

The shell material contains not more than 7.5% of magnesium, titanium, and zirconium. An external and internal ground terminal is provided.

Explosion-proof surfaces of the cover, body cover with lubricant CIATIM-221 GOST 9433-80.



Explosion protection marking Ex d IIB U/ Ex tb IIIB U
Enclosure material Stainless steel, aluminum alloy
Number of cable glands Depending on the size of the case
The degree of protection of the shell according to GOST 14254-2015 IP67
Operating temperature range -60 ... +85°С
Overall dimensions, mm 290х250х172 421х322х250 568х368х357 670х470х362
The maximum number of holes (M30) in the covers for switching at the maximum dimensions of the housing, pcs. 66
Maximum number of openings (M30) in the covers for indication at maximum case dimensions, pcs. 66
Number of cable entries (G1 / 2 or M20) on the sides with the maximum dimensions of the housing 83/95/83/95
Number of cable entries (M50B) with maximum case dimensions, pcs. 16/26/16/26
Weight of aluminum alloy without components, kg no more than 70 kg
Weight of stainless steel alloy without components, kg not more than 190 kg

Contents of delivery


Explosion-proof Shell (Ex-component) SMD MK 1 The number and type of cable glands in accordance with the order.
Manual. 1 On a batch
Passport. 1 On the product
Individual packing. 1  
Copies of certificates   On request for a batch


  • SMD Company LLC
  • 445009, Samarskay obl.,
  • Togliatty,
  • Novozovodskaya 2a street, str. 309