by William H. Black
is stored in liquid form in a steel storage container commonly referred
to as a propane tank. Propane tanks come in many shapes and sizes, and
most were designed to have a safety margin of 5 to 1. This means the tanks
were designed to hold five times their normal working pressure, which
makes them very safe, but it's important to note that your propane tank
should never be moved or disconnected without first contacting your gas
supplier. If you need a tooth pulled call the dentist, if you need gas
work done call the gas company. It usually produces
better results than doing it yourself.
Propane tanks are usually referred to by the amount of water they will
hold or water capacity. Therefore a "500 gallon tank" would
be a tank that has a water capacity of 500 gallons. It's common knowledge
that water expands and contracts with change in temperature, but few people
realize propane can expand up to 17 times the amount water will over the
same change in temperature. Therefore, to prevent too much pressure from
building in the tank, they are only filled to a maximum of 80-85% of their
water capacity to allow for the expansion and contraction of the propane.
So 85% of a 500 gallon tank would be 425 gallons. This is the maximum
amount of propane that can be put in that tank. Because of the considerable
expansion and contraction of the liquid propane, the gauge on the tank
is not an exact reflection of how much propane is in the tank. The only
exact method of determining the amount of propane in the tank would be
to weigh it. Weighing 500 gallon tanks each time you fill them is not
a very practical thing to do, so we settle for the reading on the gauge.
It is not uncommon to fill a tank on a warm April day and leave it turned
off, only to return on a chilly October morning and find it will hold
a few more gallons due to liquid contraction.
your tank's lid you will find a round or star shaped hand wheel which
shuts off the supply of gas to the house. It operates the same way as
a water spigot, as turning it clockwise will stop the flow of gas and
turning it counterclockwise will start the flow of gas. Unlike a water
spigot, there is no halfway when dealing with a propane valve, either
turn it all the way open and "snug it", or all the way closed
and "snug it". Obviously, knowing how to turn the gas off is
something all gas customers should know, so if your not sure how to do
it call your gas company. Also under the lid is usually where you will
find the liquid level gauge which can give you an estimate of how much
propane is in the tank.
propane tank placed at your home is inherently safe, but let me take this
opportunity to discuss a different kind of propane tank; the "grill
tank". This is the small 20lb. tank that you use with gas grills.
These tanks are also very safe, until you stop following the manufacturer's
recommendation and store it indoors. The place for any propane tank is
outside, not in the garage, basement, or anywhere that is a confined space.
If you have any questions, refer to the information provided by the manufacturer.