Two pipe oil distribution systems? Why put them in?

Constantin

... I thought hp-rated burners were a couple of magnitudes bigger than the stuff normally found in residences. Even my puny 140kBTU/hr boiler will sip 1 gallon of #2 an hour.... were you thinking gallons per minutes maybe? What's the conversion factor?

Eirik

oil

Hi I'm an apprentice plumber and we've been doing some work on oil lines going to 250 HP boilers in an apartment complex the guys can't explain to me why we're using lot's of pipe to put in a two pipe oil delivery system to me it makes no difference than just pumping the damn oil into the burners why the extra trouble?

Arthur

Keeps the oil circulating and gets the air back to the tank so that the burners don't get airlocked, 250 hp you will be using about 5-6 galls of oil an hour, Not a lot of oil, when the burners get the boiler to temp and shut down the oil will still circulate past back to the tank. Otherwise it would build up pressure.

Weezbo

Are you speaking of a black iron loop ,within the building?

that is so the oil is pumped out of the tank into the loop with take offs to osv that maintain constant available oil to the burners And warms the oil And extends the life on the equipment pumps And provides a means of identifying the pressure available from a location close to the tank or the most convenient point for maintenance.*~/:)

oops. I forgot to mention that 60->70 below oil does have a few issues....

RonWHC

Need that open

return line if you are going to modulate. Metering valves need a pressure drop @ the return port. On some of the LARGE input lo-hi, & lo-hi-lo burners, w/ 90 second (or longer) pre-purge, funny things happen as the oil heats up. Like cooked shaft seals &/or air where there was none before.

If the burner is gas-oil, you need to keep that oil cool when the customer is burning the gaseous stuff. Re-circulating within the pump won't do it. Need a return to the tank, or a heat exchange (cooling) loop.

Finally. If you are driving the air shutter w/ a pressurized oil cylinder, single line systems w/ head pressure, have been known to lock the shutter in hi fire when you don't want it there.