placing electric pump unit in hazardous location 3

[andimilan]

Our engineers are planning to put a portable electric pump unit to remove residual ethanol in the tank. Distance of the tank outlet to the pump unit is only 1 meter over it. The pump unit and the electric motor is a pump used for hazardous locations. As a safety officer, I do not allow it because of the placement of the pump is within the dike that protects the tank from possible spills of ethanol. Although the use of the pump is only used for 6 hours. I mean, is there a standard that allows the placement of the pump in the dike that contains two tanks with a capacity of ethanol 5000kl? thank you very much

 

[DRWeig]

If the pump unit is listed and labeled for use in Class I Div 1 Group D (NEC), AND the wiring leading to it is also suitable for that location, it's OK (safe). Of course, the best thing to do is get the electricity out of the hazardous location (safer).

Good on ya,

Goober Dave

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[Compositepro]

This sounds like a perfect application for an air operated double diaphragm pump, which is commonly used for this type of service. Electrical can work but doing the wiring connections is a pain, unless there are already explosion proof outlets already available.

 

[andimilan]

under normal conditions, we use the main pump located outside the dike. but the level of ethanol in the tank below the suction limit. so they consider to put a portable pump to remove the ethanol below the tank level by modifying the 3 inch pipe which at first is the lower limit of the sight glass. so in my mind, if the main pumps are placed outside the dike, why put a portable pump in a dike in very close proximity to the tank (1 meter)? Although the pump and motor are hazardous location type. please note that ethanol has a flash point 21 degree celsius, while the pump motor can generate heat up to 60 degrees celcius. In the event of equipment failure can cause a fire or spill. My question is, is there a standard that regulate the placement of the pump unit in the dike? If no, tell me the safest way if we had to put the pump inside the dike. I would be very grateful to you all for helping me

 

[Compositepro]

There is no relevance to correlating the 60C number to the 21C number. It seems you have a lot to learn, which we have all been through. But be careful not to be come an obstructionist where you require others to educate you to allow them to get their jobs done.

Pumps are not placed in dikes because they don't work well under water (rain water or whatever other liquid the dike may fill with). Flashpoint is not the same as auto-ignition temperature. You should study both these terms so you understand them.

 

[burnt2x]

There are equipment called "air ducts"! Place the gas extractor fan far, far away as you like. Why worry about placing an ignition source inside the area when you can just duct your problem away?

 

[DRWeig]

That the pump unit can get hotter than the ethanol flash point is not an issue -- as long as the pump unit does not get hotter than the auto-ignition temperature of ethanol. Flash point just means the ethanol is vaporizing fast enough to sustain combustion. It's not until autoignition temperature is reached that it will combust (365°C for ethanol).

In sum, there is not a standard that prohibits putting a properly-rated temporary pump in there (it could even be installed inside the tank if needed). There is a standard which specifically permits it, though.

Compositepro gave you the best idea of all -- an air-driven diaphragm pump. No electcity in the hazardous area.

Good on ya,

Goober Dave

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[micalbrch]

....yes, and make sure that it is a metal AOD pump, not a plastic one. And ask the manufacturer for conductivity of the diaphragms.

 

[PHovnanian]

Can you use a jet pump? Place the motor and impeller away from the tanks and hazardous zone, run plumbing down inside the tank to the venturi and intake located inside the tank.

 

[psafety]

Raise the pump to a level above the dike wall. Seen many pumps in flammable service inside the dike, use a pump pad equal or greater to the dike wall, this being "temporary" be creative.

Use bonding/grounding (when you say portable, it echos flex hose).