RB wrote:

Usually the whistle is located in the vent pipe just above the tank. As
the tank is filled the oil level rises and air is forced out of the vent
pipe past the whistle. When the oil begins to rise into the vent pipe
it submerges the whistle and the whistle stops making a sound.

Your answer is close, but not quite right.

I'm qualified to pontificate about this subject as 20 some years ago I spent a
dozen years of my career as the Chief Engineer of the Scully Signal Company. That
company was the original promoter and manfacturer of the whistling tank fill
signal, (The "Scully Signal") which it brought onto the market in the early 1930s.
That device made "automatic unattended oil delivery" possible. The company still
makes those whistling fill signals, along with lots of other mechanical and
electronic equipment associated with fuel oil and gasoline delivery and storage.

Prior to that invention, if the fuel oil tank was inside a house, oil delivery
required access to the inside to check how much the tank could accept and
sometimes even a second person in there watching a tank gauge, or just looking in
an bung hole, ready to bang on the vent pipe with a wrench to signal the guy
outside to stop filling.

The whistle has a hollow stem extending down from it about 5 or 6 inches into the
tank. When the rising oil level reaches the bottom of the stem, the venting
air/oil vapor stops flowing through that tube and blowing the whistle, signaling
that the tank is filled to a safe level, and leaving enough head space to
accomodate the expansion of the possibly cold oil warming up to interior
temperature.

If as you said, the oil had to be all the way up to the vent pipe to stop the
whistle, then the deliveryman would have to act super quick to shut the nozzle
before oil came spraying out of the vent pipe, and there'd be no head room left in
the tank for expansion of the oil.

The whistle and it's tube are "loose" and form a mushroom shaped gravity operated
presure relief valve which acts to keep the air/vapor pressure above the oil
relatively constant over a wide range of filling flow rates. As the flow rate
increases, the whole whistle and it's stem rises to spill the excess pressure
around it. And the whistles have a "bug screen" built right on them, because not
all vent caps are screened.

The whistling fill signal is a very simple device that almost never fails, and if
it does, it "fails safe", as the deliveryman is trained to stop filling if he
doesn't hear a whistle from the ventpipe within a second or two of starting to
fill the tank.

NOW FOR THE GOOD NEWS!

You won't have to dismantle all the vent piping. You can just cut the pipe and
rejoin it with a double ended compression coupling after you remove and replace
the whistling fill signal. There are even fill signals made with a compression
fitting on thier top ends, which you could use if you hacksaw the vent pipe right
at the top of the existing signal, providing there's enough spring in the ventpipe
to accomodate things.

I'd lean on the original installer to replace that fill signal.

Let us know what happens...

Good Luck,

Jeff
--
Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can keep smiling when things go wrong, you've thought of someone to place
the blame on."



My guess
is that insects aren't the problem since the vent cover has a screen in
it. Since the tank is only a year old I'd get the fellow who installed
it back out. Removing the vent line can be a major production but
that's the way to the whistle. Do you have an unused opening in the top
of you tank that would accept a level sensor?

RB

Steve wrote:
Hi there,

Does anyone have any sort of miracle solution to unplug a clogged up oil
tank whistle? Mine is plugged up by what I'm assuming is flies and ladybugs
(We got plenty of those this year). Air still comes out of the vent pipe
when the tank is being filled so is must be going around the whistle.

The last time the oil delivery guy was here, the tank was empty so he
had no problem filling it by watching the meter after confirming there were
no leaks (since it's a 1 year old tank). He indicated it was a one-time
deal however and that I need to get that whistle working again.

From what I can see to get the whistle out of the tank involves
dismantling the entire vent pipe. The vent pipe has about 3 joints that
would all have to be undone and involves going underneath a very shallow
(18" in some spots) deck to take it all apart. The tank installer cursed
the entire time he was under there. Now there is -20C freezing temperatures
and snow to contend with so I doubt I'd get anyone to go under until spring
time.

Is there some way to clear the blockage without pulling the whistle?
There are 3 elbows between the top of the vent and the tank.

-- Steve