Boiler fuel oil return requirements

[VoDich]

I'm replacing a couple of 500 HP steam boilers that provide heating and domestic hot water for a campus in California. Main fuel is natural gas. Backup fuel is fuel oil #2 (diesel). I believe these boilers were installed in the late 80's. There is a large diesel storage tank with diesel supply piping from the storage tank to these boilers. However, there is not a diesel return piping from the boilers back to the storage tank. No day tank in between either. The boiler rep is telling me that I'm required to have a diesel return piping from the boiler back to the storage tank. My questions are:

1) Am I required to have a diesel return piping from the boilers back to the diesel storage tank? If so, which codes or standards have this requirement? NFPA? ASME?

2) Can one small (100-200 gallons) diesel day tank be placed near these 2 boilers to run diesel return piping from the boilers to? Would this be adequate to not have to run a diesel return piping all the way back to the large diesel storage tank that is several hundred feet away?

3) What really happens to the boiler or burner if there isn't a diesel return piping, provided that the flowrate and pressure at the burner are adequate?

This isn't the first site where I have seen boilers without a diesel return piping. That's why I'm a little confused on why the boiler rep and day tank rep are telling me that it is required, yet a few sites I have seen do not have it.

Thanks!

 

[TBP]

What do the burner manufacturer's installation instructions say?

 

[VoDich]

Thanks for the input TBP. Per the boiler installation manual, a two-pipe (supply and return) oil system is recommended. It's recommended. In my case, I don't want to have to do a change order to add a return piping if it's not required.

 

[MJCronin]

How did your bulk Diesel supply tank end up "several hundred feet" away from your boilers ? Which MBA within your organization was responsible for this ?

What is the back story ?

You have not mentioned a Diesel fuel oil supply pump yet ...

Does one exist and does it still work ? Is it a PD pump or What ??...... SUPPLY PICTURES !

Remember, the fuel oil must be transferred from the bulk storage tank to the day tank (which is at atmospheric pressure)

You you may want to consider the purchase of an integrated solution, a NEW Custom Day Tank/Fuel oil pump/Recirc loop and controls

Many people offer this as a package

https://www.preferred-mfg.com/products/fuel-handling/day-tanks/custom-day-tanks.html

MJCronin
Sr. Process Engineer

 

[LittleInch]

You haven't said anywhere in this how the diesel gets from the tank to the burners.

Gravity?
Pump at the tank?
Pump at the burners?
Type of pump?
Did the boiler rep say why it was needed?
Is the flow of diesel a steady flow or variable?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[TBP]

If nothing else, be aware that the boiler rep is establishing a "get out of jail free" card on any & all oil burner issues you may have with these boilers if you do not install a recirc line back to the tank.

 

[MJCronin]

No more involvement Vo ?

No detailed discussion of the type of Boilers, type/manufacturer of burners etc etc???

No explanation of why the diesel storage tank is in the next zip code ???

Take a picture of the burners

You got what you want, so F everyone else ????

Please complete the thread and tell us of your final decisions and design ....



MJCronin
Sr. Process Engineer