Page 175 - GarlockFluidSealing2010

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CHEVRON® Installation
and Adjustment
Protect your investment. Do not hang Garlock CHEV-
RON® packing on nails or under any excessive stack
pressure that might deform the concentricity of the prod-
uct. Do not stock in extreme weather conditions. Avoid
constant sunlight. The elastomer compounds used in
CHEVRON® packing are highly technical and, while reli-
able, they are subject to handling stress.
1. Packing on a mov-
ing ram should be end-
less rings, if possible,
for best service life.
2. If rams are grooved,
worn, rusted or cor-
roded, they should
be reconditioned or
replaced. No packing
stands up to these
conditions. Use boots
to protect rams if abra-
sive dust is a problem.
3.On high pressure jobs, make clearance between rod
and gland as close as possible to prevent extrusion.
4. If lubrication is not getting into a Garlock CHEVRON®
packing set, the gland may be drawn up too tightly and
should be loosened appropriately. To avoid over-tight-
ening and/or cocking of the gland, place a shim under
the gland.
5. If a stuffng box is very deep, spacer(s) can be used to
take up the space of additional CHEVRON® rings that
are not needed. This saves replacement time and cost.
6. Use the correct style. For example, don’t use butyl
against a petroleum base oil, or a nitrile against a phos-
phate ester.
7. Use the right size. In emergencies, “off-size” parts can
be distorted and made to work for a short period of
time, but do not expect them
to last or work as effciently
as the correct size.
8. Make sure all rings are
seat-ed with no voids in the
set.
9. Use lubrication when in-
stalling the rings, as it makes
installation much easier and
helps during the break-in
period.
10. Make sure sections of the lips of the rings are not
turned over or twisted. This is easy to do, especially
in blind installation, and will result in premature leak-
age and
failure.
11. Make sure the packings are facing in the direction
of the medium being sealed—whether liquid, air, dust,
etc.
12. Consider metal structure. Many times a packing is
blamed for leakage when the real culprit is porous
metal—either the rod or the housing.
13. Let Garlock help you. Tell us about the application.
If a forging press is under shock load, then packing
must be a more rugged type, for example. Or, if low
pressures are involved, the packing selection must
be more fexible than for high pressure.
14. Don’t use sharp metal tools like screwdrivers when
installing packings. Hardwood tools are best and will
not score rod or stuffng box.
For installation of endless CHEVRON® packing,
gland pressure should be only suffcient to snug rings
within the confning cavity.
On split ring installations, adjustment practice will
vary depending on service conditions.
For horizontal packing installations, nominally light
gland pressure is necessary to seal the ring joints.
Adjustment is made by turns of 1/4 fat on gland
bolts.
On vertical applications of split rings, it is desirable
to provide increased gland pressure for the effective
seal of ring joints.