positive displacement gear pump

[mazen448]

hello

is it must to use explosion proof motor with positive displacement (gear) pump

the application is fuel transfer
ul listed internal gear pump

is there any code explain thank you

 

[MortenA]

API 676 covers positive displacement Pumps-Rotary

 

[moltenmetal]

Well...there are "fuels" and there are "fuels".

Typically a pump handling flammable fuels (gasoline etc.) will be at very least Zone 2 (division 2), meaning it is in a service where a flammable vapour is not normally present but might be in an upset condition such as a leak. However, if leakage is viewed as more likely, or the component is located in an area where a denser-than-air vapour may accumulate when released, it could be Zone 1 or even Zone 0 (i.e. assuming a flammable vapour will be normally present). Zones 0 and 1 require explosion proof motors per API 500, NFPA 497 etc. and per NFPA 70. Those are codes associated with the selection of electrical equipment such as motors for potentially hazardous services due to fire risk.

In Zone/division 2, explosion proof motors are not required. 3 phase TEFC motors are permitted as long as they contain no arcing/sparking components. Some will argue that the motor needs to be identified on the nameplate as suitable for use in a hazardous area, and that's easy enough to obtain most of the time and it shuts people up so you don't have to argue with them, but I'm still not convinced it's an actual requirement of NFPA 70 (the US National Electrical Code) or the CEC.

In Europe and some other jurisdictions, there may ALSO be rules related to the mechanical components and their ability to generate sparks or heat- not just with the motor.

If your internal gear pump is using single phase AC or is using a DC motor, explosion-proof will be your only option.

If your fuel is combustible rather than flammable, i.e. heavier than diesel (even some diesels have a high enough flash point to be combustible rather than flammable), unless the equipment is operating with the fluid at elevated temperatures, it isn't a Zone 0, 1 or 2 situation unless it is co-located with other equipment. Other rules may apply and may require hazardous area treatment though- you need to know the complete suite of safety and regulatory requirements for your company, region and country to make the right selection.

 

[mazen448]

thank you moltenmetal
the fuel is diesel
and the system is fuel system for diesel engine

where i can find this zones


thank you

 

[moltenmetal]

I've personally never seen an engine fitted with explosion-proof components. But you'll have to check your local electrical regulations to be sure.

 

[MortenA]

I would say the diesel in itself does not cause a zone two (not high enough vapour pressure to be a gas). But the motor may be in a zone 2 anyway.

Best regards, Morten

 

[GroovyGuy]

Howdy ya'll,
MortenA is correct, the vapor pressure of diesel fuel does not constitute a hazardous area. Therefore, no Zone 2 rating for electrical equipment is required.

"I have not failed. I've just found 10,000 ways that won't work." Thomas Alva Edison (1847-1931)

 

[moltenmetal]

Be careful, as some diesels have a low enough flash point to be considered flammable rather than combustible- and a combustible fluid operating above its flash point can still fall into the category of potentially generating a zone 2 environment. So it depends on the application. We agree that if this is transferring motor diesel stored at ambient conditions it would generally be considered a nonhazardous area classification- unless it were parked within the zone of influence of a gasoline tank etc.

 

[bimr]

With the limited information that was posted by the OP, little is known about the application of this particular engine. Some diesel sets may be used to burn other types of fuel such as biogas or used oil, which may change the responses.

It would be helpful if the OP will give a better description of what the application is.