Leak-Free Connections
Ever notice how an oil leak attracts dirt? As the leaking continues
the oily mess grows. One of the primary sources for leaks is a poor
fitting connection. Leak-free hydraulics has always been desired
but few know that the solution has been available for some time.
Manufacturers are slowly eliminating problems which could have been
prevented over 20 years ago.
Oil leak prevention has a friend. Flat Face O-Ring (FOR-Seal)
fitting and hose ends will virtually stop all connector leaks. FOR-Seal
style fittings and hose ends from 1/4" - 1" are rated
to 6,000 psi.
Note: Just because the fittings and hose ends are rated to 6,000
psi, this in no way allows for 6,000 pounds of pressure to be used
in most hoses in use today. Each hose has its own pressure rating
which, in most cases, is substantially lower than 6,000 psi.
What is a Flat Face O-Ring connection?
FOR-SEAL fittings have a recessed o-ring groove machined into
its face and
the matching hose end has as its mating surface a smooth flat surface
to which is
drawn up tight to the fitting by a nut, similar to a JIC female
hose end. The o-ring
provides a better seal than the traditional pipe thread.
There are two types of o-rings used in FOR-Seal fittings.
Most o-rings used are 90-durometer buna-nitrile that can handle
temperatures of 250°F. The second type is Viton o-rings, which
can handle temperatures of up to 400° F.
A number of advantages can be realized when using FOR-Seal
type fittings and hose ends. Because the hose end is tightened to
a mating adapter by a swivel nut, the hose is free to be positioned
where wanted and not subject to kinks and alignment problems at
installation.
Metal to metal connections stretch with repeated uses such as pipe
threads and JIC fittings, but the FOR-Seal fitting is renewed
each time the connection is broken by the insertion of a new o-ring.
FOR-SEAL fittings also have a higher tolerance for vibration
than metal to metal connections.
Let's look at some "rule of thumb" pressure definitions:
Low pressure - up to 1,250 psi
Medium pressure - 1,250 - 2,000 psi
High pressure - 2,000 - 3,000 psi
Very high pressure -3,000 - 5,000 psi
Late model tractors and heavy equipment have had 2,500 psi hydraulic
systems for over 25 years and newer machines will have system pressures
that are or will be higher in the days ahead. The days of tapered
pipe fittings will be coming to an end on newly engineered products
from large corporations if in fact they have not already made the
switch to some type of o-ring seal fitting and hose connection.
What the military pioneers, soon follows for the private sector.
As technology advances, higher pressures are expected on equipment
coming from manufacturers. Newer types of sealing techniques are
here. We need to be ready to meet the challenges when the need for
repair or replacement of parts arises.
FOR-Seal is a product name for a hose end configuration using
an o-ring sealing method, trademarked by Dana Corporation.
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