Fuel oil piping layout

[MagicJS]

Hi, what's a good reference (online or off) for boiler fuel oil piping layout. Mainly I need to know when it's ok to use only burner mounted pumps without a recirculating loop. I've read ASHRAE fundamentals and it just gives you pipe sizing & a recirculating system schematic. I would prefer a more detailed explaination of both methods. Thanks.

 

[rmw]

The need for a recirculation loop (or not) would be burner specific, depending upon whether or not the burner required recirculation.

rmw

 

[lilliput1]

If you only have one boiler and one tank you can use the burner mounted pumps. If you have a main tank and a day tank you need a transfer pump. If you have multiple boilers, with or without day tanks, you need a recirculation system with a main pump that would insure positive pressure at each boiler burner pump suction.

 

[Drazen]

What I have available at the moment is based on German DIN norms, but every serious burner manufacturer will usually offer you several layouts of oil piping.

Normally they tell you if it is possible to use burner pump only. It is dependant of lenght of piping, heigt difference between oil tank and burner and is generally applicable for one-burner layout. (I know the solution where you run piping for two burners separataly from tank - separate connections for piping even at the tank flange - where you don't have to use the additional pump.)

Seek manufacturer documentation while selecting burner(s)!

 

[lilliput1]

Preferred Inc. has a good pamhlet on fuel oil piping. It discuss (2) way of arranging the return - either direct back to tank or direct back to the supply where it can feed downstream boilers. Main pump sizing for each is different. Note that burner pumps circulate twice or more rhe actual boiler maximum firing rate. You have to account for this in sizing the piping & main pump.
Drazen is correct. You can also run dedicated supply & return to & from each boiler burner pump instead of a single recirculation loop.
Another thing. Diesel is different from No. 2 fuel oil. Diesel has antiknock additives. So if you have diesel generators they need a diesel fuel & tank system, separate from the fuel oil system.
New underground systems use double wall flexible fuel oil piping (available up to 2.5" size). This is less expensive & more reliable than steel pipe within PVC conduit.

 

[PEDARRIN2]

It is fairly common for owners to use fuel oil in the place of diesel for the fact that they do not need two tank systems.

I have run into that problem and have tried to ascertain how to convince the owner that although they are very similar, they are not the same.

How would that be accomplished?

 

[lilliput1]

Get confirmation from diesel generator manufacturer that the diesel generator require diesel fuel, not number 2 oil and that their warranty would be only based on using diesel fuel.
It is possible to get antiknock additives to No. 2 fuel oil however this require good record keeping & fuel usage measurment to be effective.