Oil Vent Too High?

Mike R._2

Several times there have been notes on my oil delivery ticket that say “weak VA” or “low whistle”. One time there was a wasp nest clogging the vent, but other times it was clear. The last ticket I have says “Vent too high”.

Here’s the setup – the tank is in the cellar and the cellar floor is about 6 feet below grade. The fill pipe, 2”, is about 2 feet above grade and the vent pipe, 1.25”, is about 6 feet above grade.

Would it make any difference if the vent was shorter? I’ve noticed that new installations use a 2” vent that is usually not much higher than the filler; does this make the va work better?

Thanks,
Mike Rastelli

[Deleted User]

Good description

of what you have. I will try to fill in the blanks.

The VA (ventalarm) whistles when fuel oil is being pumped into the tank. When the fuel level gets to the bottom of the tube in the ventalarm, the whistle stops. Then the driver turns the nozzle off. The tank is full to the safe level.

The driver must be able to hear the whistle while he is filling the tank. That means hearing it over the noise of the delivery truck, passing traffic, barking dogs, blaring radios, etc. If the whistle is weak, he keeps his ear close to the vent. If the vent terminates further than arm's length from the fill, he might not be able to turn off the nozzle before his ear turns red with oil spitting out of the vent, or oil spilling out the fill when he disconnects the nozzle.

That is a good reason to terminate the vent as close as practicable to the fill. Just keep the vent termination above the anticipated snow line for your area.

Many older tanks have 2" fills and 1 1/4" vents. Several years ago NFPA changed the code to require 2" vents when there was a 2" fill, on new installations. Good requirement. But, they revisited it in 2001, and 1 1/4" vents are now allowed. I hope this helps.

Mike R._2

Thanks

for the explanation, that does help. It shouldn't be too much trouble to shorten the pipe.

kevin

1.25\" vents

are now OK per NFPA regs on new intalls w/ 1.25 fills? Did I understand that right.... beats threading 2" by hand...kpc

todd s

Piping

Yes this is how 2001 edition states. Also piping may only be steel, wrought iron, or sched 40 brass. NO COPPER.

J.C.A.

KPC,

The rule is that the vent must be at least as large as the fill . For 1 1/2 inch fill, 1 1/2inch vent .

I think N.H. stayed to the 2" vent regardless, but they will catch up . Chris

Firedragon_4

NH

Hi Chris,
They caught up on November 8, 2002 by adopting NFPA1. NFPA is now the 'law-of-the land' in NH.
1-1/4" all around with no copper and NO pvc anymore.
Most oilmen are happy, hacks are crying, big time!

PS: It almost knocked me on ma butt to find this out, but in the 5 boroughs of NYC, it's a 2" fill, 1-1/4 vent and has been since the 1930's. Proving once again that the biggest isn't always the.................
;-)

Bluenose_12

vent

In Canada, B.139 standard now states vent must terminate no less than 2 metres(6.5FT) from ground level. Don't ask me why, we just follow the rules.