oil filter height on 2 line system and bleeding

ron

have a lunchtime question....

The existing 275gal vertical oil tank is drawn from the top and has a General 2A-700 filter (the larger one) located basically at the top of the tank height-wise. Then the 1/2" oil lines run down on the floor to the boiler about 10 feet away.
There's an inline fireomatic valve on the supply line between the tank and filter, and then others at each burner.

Regarding changing the oil filter in this type of scenario, I expect to be able to open the General 2A and do the filter without having to close any valves on the oil line- I should just loose the pint of oil in the General 2A can. But with a new filter and a pint full of air in the filter canister what is the best way to bleed the system? I am unfamiliar with capabilities of 2 line oil piping; I am thinking I need to disconnect the 1/2" oil line at the boiler burner and the hot water heater burner and drain all the oil when changing the General canister filter and then using a vacuum pump to draw oil all the way to each burner (which will take care of the filter canister) ?

With a 2A-700 filter can full of air and 10' of 1/2" oil line empty how dangerous is that to the oil pump?

Jon_blaney

If it were me, I would close the firematic at the tank which should keep the supply in the tank full. Change the filter and top off the can with oil. The supply line beyond the filter will stay full. Should prime fine.

STEVEusaPA

You would only need to clear the oil lines if there was a problem with the oil.
Do you have a 2 pipe set up, IOW fuel line goes to both burners and a fuel line comes back to the tank from both burners. If so, it's self priming.
What @Jon_blaney stated would work. I'd go a step farther as you should also change your pump strainers. First I'd turn on a burner, open the bleeder and catch about a cup full of oil in a cup.
Then I'd close (you should have) the firomatics at each burner, change the pump strainers, leave firomatics closed.
Next, with a pan under the filter housing, close the firomatic at the tank, remove the bowl. Clean out the bowl, new gaskets, etc. and pour the cup of clean oil into the filter, about 1/2" from the top. Reattach the bowl.
Open all the firomatics, run one burner for a few minutes (good time to check the safeties). Shut that off, run the other burner. You may have to reset the burners once or twice.

Now if it's just a single pipe set up (no returns to the tank), then you'll want to do a power vacuum bleed.

EBEBRATT-Ed

You should have a firomatic valve at the tank at the oil filter inlet

EdTheHeaterMan

Also. Important. On a 2 pipe system, there should be no fir-o-matic valve on the return line to the tank. if that were to close first during a fire event, and the burner was operating when the valve shut, the pump seal would fail and there would be oil all over the place. (ask me how I know). NFPA 31 also states there should be no valves to restrict a fuel return line from a pump to the fuel tank

STEVEusaPA

EdTheHeaterMan said:

However, 8.7.7 goes on to say..."except for a hard-seat or ball valv that shall be left in the open position, with the handle removed, and shall be left in the open position, with the handle removed, and shall enter the top of the same tank."

EdTheHeaterMan

STEVEusaPA said:

EdTheHeaterMan Said: NFPA 31 also states there should be no valves to restrict a fuel return line from a pump to the fuel tank

However, 8.7.7 goes on to say..."except for a hard-seat or ball valv that shall be left in the open position, with the handle removed, and shall be left in the open position, with the handle removed, and shall enter the top of the same tank."

Yea... that... you get the picture!

I made the mistake of closing the wrong valve to test pump vacuum while the burner was operating. lots of oil everywhere, inside the burner, all over the fan, in the chamber, running down to the floor below the burner. Was a real mess. But after I replaced the pump I was testing (since I knew it also had a bad seal after that) the burner ran great.

STEVEusaPA

EdTheHeaterMan said:

I made the mistake of closing the wrong valve to test pump vacuum while the burner was operating. lots of oil everywhere, inside the burner, all over the fan, in the chamber, running down to the floor below the burner. Was a real mess. But after I replaced the pump I was testing (since I knew it also had a bad seal after that) the burner ran great.

I'll do you one better...well way worse-about 2 years into doing service.
Church, 2 furnaces, 1 oil-fired w/h, all 2 pipe. Closed supply/return to do service, change filters, pump strainers, vac, etc. Get everything done...ready for combustion testing.
Forgot to open return back up.
Fired up furnace #1, within a few seconds I see oil. Shut it down, figured I forgot to tighten up something-maybe the nozzle line or strainer.
So let me fire up #2, while it's warming up, I'll tighten up #1. A few seconds...OIL!!! Shut it down and then it hit me that I left the return valve closed.
Luckily I didn't go for #3.
But I did get to change two fuel pumps for free.

EdTheHeaterMan

@STEVEusaPA. That is one of those things you only do once. (like touching the buss terminals on a live ignition transformer). But you had the privilege of doing it twice. Live and learn.