Ball-lock vs. Pin-lock Quick Disconnect Fittings


	This is a small treatise on why use one or the other of the
two types of kegs and their fittings available.

	For some background, pin-lock fittings are proprietery to the
Coca-Cola company and are only used on their products.  The ball-lock
fittings are what are considered "general beverage" in the beverage
industry and are used by every other supplier of beverages.  Also, in
the beverage industry, these kegs are referred to "soda syrup
canisters".

	Because the ball-lock fittings are used by many more companies
than the pin-lock, they are more readily avaiable and kegs with them
are generally about $5 cheaper than those with pin-lock.  Also, if you
want to build any sort of specialized equipment on top of a QD
fitting, the ball lock have many more kinds of adapters available
(like to 1/4" NPT), while with pin-lock, only 1/4" hose barb, or 1/4"
flare are the only adapters available.

	Size may come into play in your decision of which type of kegs
to use.  The ball lock kegs are taller and thinner than the pin-lock
kegs.  The pin-lock are generally about 2" shorter and if you are
planning on stacking kegs in a fridge, may make the difference in
being able to get two layers high or not.  There are actually several
different heights for both styles of kegs.

	Surety of connecting the QD fittings should also be considered
in your decision.  With pin-lock fittings, it is impossible to get the
gas and liquid fittings reversed.  With ball-lock fittings, it is
possible to force them onto the opposite fittings, and once forced
on, they may never come apart.  Also, ball-lock fittings can fool you
into thinking they are "seated" when in fact, they are not.  Once a
pin-lock fitting has been turned onto the pins, it is absolutely
guaranteed to be seated.

	Over time, and with grunge buildup, ball-lock fittings will
tend to become difficult to attach/detach.  The area of the balls is
very difficult to clean.  There is no such problem with pin-lock.

While that may not be true with beer fittings, since people clean them
frequently, I have run into this problem with ball QD fittings in
non-beer applications.  This statement refers to both the grunge build
up and the problem with not being absolutely sure that they are
seated.  My only experience with ball lock fittings is in "non-beer"
applications because I use pin lock fittings exclusively for beer.  I
put in this warning because is some situations, this occurs,
evidently, the frequency in beer fittings is less than my non-beer
experience would indicate.