valve for propane cylinders
Federal government will prohibit the sale and use of POL
valves found on most older DoT type propane cylinders. (POL
is an abbreviation for Prest-O-Lite, for the company that
first produced the valve). These valves have the familiar
female left-hand-thread in the valve and are the type most
of us currently have. Cylinders with this type valve may
not be sold beginning in the year 2000, and may not be refilled
beginning in 2002.
old POL valves are being replaced with a new Acme type which
uses a QCC (Quick Closing Coupling) connector. This connector
has an external (male) right-hand thread on the valve. A
pigtail hose can be connected and disconnected by hand...
no wrench required. These valves also have the old-style
POL internal left-hand thread, so they can be used directly
in place of the old valves without modifying your RV. If
you like the no-tools convenience of new style connector
you may want to replace your pigtail hoses with new ones
having the QCC connectors.
new ACME or QCC valve also contains an OPD (Overfill Protection
Device). So you may find them called ACME valves, OPD valves
or QCC valves, depending on the supplier. The OPD feature
prevents accidental overfill of the cylinder. An internal
float mechanism shuts off the valve when the cylinder is
80% filled. The 20% empty space is necessary to prevent the
cylinder from venting large amounts of propane when the temperature
rises. (ASME type cylinders in most motorhomes have had this
OPD feature for many years). The new OPD valve also contains
another safety feature - it will not release gas unless the
pigtail hose is properly connected, even with the valve open.
old-style cylinder valve is known as a POL valve, named
for the manufacturer that devised it. You tighten the connector
of the regulator pigtail by turning the fitting counter-clockwise,
and you usually need to use a wrench to make the connection
tight enough to prevent leaks. With a POL valve, if
you open it with no fitting attached, propane is freely
released. That's why a plug is required to be screwed
into the valve during transport of the cylinder and
when it is stored or not connected to your RV. The
plug is an attempt to prevent an accidental opening
of the valve from creating a dangerous situation.
valve also has a built-in bleeder valve the service
technician uses to check for proper filling and a pressure
relief device to prevent over pressurization of the
valve is also known as QCC (Quick Closing Coupling)
or OPD (Overfill Protection Device) The New ACME valve
looks bulkier because there are external threads visible.
The external threads don't necessarily require a change
to the connector on the end of the regulator pigtail
hose. They are compatible, as the left-hand-thread
fitting on your RV regulator will screw into the internal
POL threads of the new ACME valve.
one of the benefits of the new connector is that it
is designed to be attached to the cylinder without
tools. You only have to hand-tighten the connector.
And, you tighten as you would normally tighten a threaded
fitting, by turning it to the right (clock-wise). So
at the cost of a few dollars it may be good to replace
the pigtail hoses.
you have an older RV you should know that according
to Federal law, DoT cylinders may only be used for 12 years
after their manufacture date. After that, the cylinders must
be "recertified" which provides another five years of use.
The cylinders can be recertified every five years thereafter.
because your old cylinders no doubt have the old POL type
valves, you will effectively only have two more years of
use since these cylinders may not be refilled after 2002.
It may well be cost effective to buy new, compliant cylinders,
rather than go to the trouble and expense of getting your
old cylinders recertified. This is especially true with the
smaller 20-pound cylinders. Check with your propane dealer
and compare costs.
dispensers are legally required to look at the date stamped
on the cylinder before filling it. Some dealers actually
do look. We've been reminded a few times that our cylinders
were about to expire. Check the date stamped on your cylinders...
don't rely on your rig's model year even if the cylinders
are original. It's quite possible they are a year or more
older than your rig. Ours were.
is usually done by the large bulk propane suppliers but we
found one of our local RV repair shops was certified to do
the job and they do it for free! Call around to see who may
do it in your area.
safety note for you: Propane
cylinders of the DoT design must be transported and stored
in an upright position so the pressure relief device
will function properly. Laying the cylinder on its side
in the trunk of your car is a potentially very dangerous