IEC Grease

[Kobe85]

When we typically do gland installations for IEC areas, we use 90 degree adapters since a lot of our devices are very close together on a gauge panel.

In order to tighten these 90 degree adapters, we need a locknut. As a further note, we use Crouse-Hinds STL grease on the threads to maintain the IP rating and DO NOT use a sealing washer.

We recently noticed IEC 60079.14 states that for Ex d equipment - this grease must be non-metallic. Crouse-Hinds STL grease says it is lithium based (albeit <7%).

Could <7% considered non-metallic? The code does not say. What's even more annoying is earlier in IEC 60079.14, it states conduit fittings on Ex d equipment can use a grease but it does not include the wording "non-metallic" in the grease types.

We've had some issues getting this grease passed by our customer, but I'm not sure whether or not it is really violating it since it is such a small portion, and I am having trouble finding a grease that meets the code and is not metallic. If we do not use the locknut and use a sealing washer instead, we cannot set the final pointing position of the 90 degree adapter (which could be in any direction where it tightens). This is a huge issue. I understand there are union/90degree adapters that could be used, but these are very expensive.

Anyone else have similar issues?

 

[don_resqcapt19]

How does a thread lubricant maintain an IP rating?

 

[Kobe85]

How does a thread lubricant maintain an IP rating?

Don't have an answer for you, but it's on the datasheets and installation manuals that it is acceptable in replace of a washer.

 

[Smart $]

How can you have an IEC area...

IEC is not an adopted law or regulation anywhere in the States, is it?

Hazardous locations are subject to the purview of the laws and regulations on the subject at the AHJ level.

IEC would only apply to manufactured goods intended for an IEC market. And if this is the case, then simply a matter of getting the IEC compliant "grease"... which will most likely come from an IEC marketplace.

 

[don_resqcapt19]

Don't have an answer for you, but it's on the datasheets and installation manuals that it is acceptable in replace of a washer.

I would have to see that on a listing document from an NRTL before I would accept that. Most IEC products are not listed by an NRTL.

 

[Kobe85]

Sorry for the confusion, the skid is going to Australia. At my company we build skids for all over the world, so in this case we are under IEC and IECEx markings.

 

[SceneryDriver]

The "lithium" in lithium grease is not metallic lithium. If it were, it would most likely catch fire, or at least quickly corrode, in a normal atmosphere.

https://en.wikipedia.org/wiki/Lithium

"Lithium" in grease refers to lithium stearate, a chemical used in the manufacture of said greases. Lithium stearate is no more metallic than is sodium chloride (table salt).

https://en.wikipedia.org/wiki/Lithium_soap

So long as the grease is chemically compatible with the components of the cable glands, there will be no reaction. Greases with metallic and graphite fillers do exist, and this is what the code is most likely prohibiting, as they can be reactive.



SceneryDriver

 

[Kobe85]

The "lithium" in lithium grease is not metallic lithium. If it were, it would most likely catch fire, or at least quickly corrode, in a normal atmosphere.

https://en.wikipedia.org/wiki/Lithium

"Lithium" in grease refers to lithium stearate, a chemical used in the manufacture of said greases. Lithium stearate is no more metallic than is sodium chloride (table salt).

https://en.wikipedia.org/wiki/Lithium_soap

So long as the grease is chemically compatible with the components of the cable glands, there will be no reaction. Greases with metallic and graphite fillers do exist, and this is what the code is most likely prohibiting, as they can be reactive.



SceneryDriver

Thanks for this. Unfortunately at the time I didn't check the chemical on the MSDS like you did above and I didn't think it would come up as a soap. Great information to save though!