Interpret the EN12115 standard for antistatic hoses

With the development of industry, more and more enterprises on the safety of production requirements more and more stringent, environmental awareness is becoming stronger and stronger, in the environmental dust removal to eliminate static electricity is also more and more attention, because do not eliminate static electricity will have a great risk to enterprise safety. Therefore, when enterprises purchase material conveying hoses, they are required to have the function of conducting static electricity.In industrial production, the rapid movement of materials is a way to generate static electricity. Static electricity does not produce current when it is at rest, but in industrial production, it is not the same. Production accidents caused by static electricity have occurred at home and abroad. However, European countries earlier put forward the protection of static electricity, but also developed a more complete protection standard - EN12115 standard. The current version is EN12115:2011andIEC60079-32-1:2011. The new and old standards clearly define the requirements for anti-static hose.We can see on some hoses Ω, M, Ω/T, M/T several signs, these signs are on behalf of the hose has the function of conducting static electricity, but what is the difference? The old version of EN12115 only had two standards of Ω or M, but EN12115:2011 adds two Ω/T and M/T to this basis.●Ω/T= High security requirements. The hose as a whole is made of a mixture of conductive rubber. The resistance between the walls of the tube is 109Ω. The mixture suitable for the interior is an explosive medium and is used in the hazardous area (the whole or main part of the pipe assembly is in the explosion area). Suitable for classes with explosive media higher than IIA (IIB or IIC). Also suitable for key non-conductive chemicals such as toluene.●Ω= High security. Made of a conductive rubber mixture. Suitable for normal use, such as filling liquids corresponding to IIA. Such hoses may also be accepted if they are partially used in hazardous areas - for example, the explosion-proof area is restricted to the joint area.●M/T= In most cases, this type of hose can be used as Ω/T hose. However, in contrast to the Ω and Ω/T hose assembly, this hose must consider its electrical conductivity to be achieved through a metal conductor. The connections of metal conductors are subject to high fluid loads and can break in some cases. Therefore, it is necessary to measure the resistivity of the hose assembly regularly. Further, in the case of the so-called stray current in the environment, try to avoid the use of M/T(or M) hose.●M= Suitable for normal use. For example, fill the liquid corresponding to the explosive Group IIA, but this type has the same restrictions as the hose use of M/T.When we talk about the electrical conductivity of a tube, we cannot think that a tube with low resistivity is a good conductive hose, such as a hose with copper wire conducting static electricity, because low resistivity will produce a large current, and there is also a hidden danger of sparking. The inner wall does not conduct static electricity, but the strengthening layer and the outer rubber also have a certain risk, when the external charge is high enough, the inside of the hose may be broken down. Therefore, the recommended choice is Ω/T hose (wall resistance < 109Ω).