Piping through or over earthen berms at tank farms

[cvyk]

Is it a better plan to run piping up and over berms rather than through? We have always run thru berms with single wall steel pipe, sleeved at side penetrations (and welded to liner); however it seems many installations use "over the berm" piping. If so, I guess one has to allow for berm "head" on pumps; anything else? any extra valves required? I have never actually seen this type of piping in practice.
Thanks.

 

[BigInch]

I usually prefer over, unless its hot gasoline, etc. where NPSHA is critical.

No extra valves required.

Going over the top preserves integrity of the earthen berms and does not expose the pipe to soil loadings or restraining forces caused by the berm and your sealing mechanism, so it is somewhat preferable in that regard.

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"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[Daianto]

Thanks Big Inch.

Does one use regular pipe supports when piping goes over berms? Any special valving I need? I don't have any info on this way of doing it.

Daianto aka cvyk

 

[BigInch]

Nothing special required. Pipe rack, T supports, whatever. Be careful because sometimes fire and emergency vehicle access is along the top of the berms in some situations, so you don't want to block that. Check their access routes and headroom clearance reqirements.

No extra valves needed either. At least in any circumstance I've ever had.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[Daianto]

Thanks! Appreciate it.

 

[Daianto]

I am hearing rumours that this sytem WAS used in this organization here in past but did not work well- due to fact that the the valve at each end of piping going over berm (ie, outlet valve at storage tank and the valve at d ispenser building at other end were (obviously) at lower levels than the highest part of piping crossing berm..I don't see what ill effects could occur as long as valves are opened and shut properly....Any thoughts?

 

[BigInch]

I would guess its that, if the low low tank pumpdown level is below the berm elevation where you would need a siphon to maintain the flow over the berm, the pumps could lose NPSH and have to stop. That would be one of those NPSH problems that could force you to pipe through the berm wall.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[BigInch]

Or go undergound all the way.

Above-ground pipes within the berm, yet lower than the berm top elevation, might need to be weighted or clamped down in the event of a tank failure. You wouldn't want any empty pipes to be buoyed off their supports.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[Daianto]

have had NPSH problesm even with thru-berm piping,...due to level differences not having been taken into account-inside of berm lower than outside..

 

[BigInch]

In that case I would go out of the tank, through the valve, isolate, turn down, then underground all the way to the pump.

What product and temperature is it?

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[cvyk]

Most of our facilities are gasoline or LSDL, some have Jet A-1. Product is not heated or cooled, so it is at whatever temp it becomes in the lines (aboveground singlewall steel). Yearly (or even daily) air temperature variation is substantial...Air temps can be minus 45 C or more in winter and in summer air temps can reach over 35 C or more, in 24 hr sunlight...

 

[BigInch]

Pumping gasoline over 40-45ºC gets to be problematic because of its high vapor pressure, but the others would be OK at that temp. At the low temperature, diesel might start turning into jello.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[Daianto]

Thanks..I am not aware of low-temp probl;ems with our diesel but should find out. I have been told the last few years the different additives in diesel tend to muck up equipment more than used to be found....

 

[chicopee]

cvyk, EPA inspectors may inquire about the integrity of the berm where the pipe penetrates it and what provision and testing against corrosion are being implemented. Piping over the berm is a solution as long as some of the rpoblems mentioned in the above posts are addressed adequatly.

 

[Daianto]

The pipe is sleeved (only at sides of berm) and there welded to membrane. I think we should be sleeving it all through the width of berm. We have not had any EPA or similar questions (in Canada) but are trying to anticipate upcoming changes in regs..