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Die-Formed
Many compression packing materials can be sup-
plied in a pre-compressed ring form, which provides
controlled density and size.
Mandrel Cut
Rings formed by wrapping braided stock of the
required cross section on a mandrel or shaft with a
diameter equal to the desired I.D.
Graphite Tape
Flexible graphite tape (ribbon) is manufactured by
exfoliating (expanding) and then compressing natu-
ral graphite fakes to a specifc density. Graphite has
almost universal chemical inertness and is naturally
lubricious, compactible and resilient, as well as nuclear
radiation resistant.
Flexible graphite tape can be die-molded or com-
pressed to form endless true labyrinth rings. Graphite
tape packings have a low coeffcient of friction, a pH
range of 0-14 and are noted for their excellent thermal
properties enabling them to be used in applications to
5500°F (3000°C) in non-oxidizing atmospheres. Due
to their temperature resistance and density, they make
ideal valve packings in steam, VOC, hydrocarbons or
chemical applications when used in combination with
braided end rings such as Styles 1303-FEP, 98 or
G-700.
Lubricants
Lubricants are usually added to compression pack-
ings when the packings are to be used on rotary equip-
ment where frictional heat is generated. The lubricants
provide a resiliency that allows the packing to deform
and recover under slight mechanical defciencies such
as shaft defection. They may also provide interfber
lubricity that reduces frictional heat.
Blocking Agents
Lubricants that act as a fuid barrier by closing the
voids that are present in braided materials to prevent
leakage through the cross section of the packing.
Single End Coating
A proprietary Garlock process that coats each yarn
used in packing prior to the braiding process. This
provides a more consistent coating of packing materials
for better sealing.
Material Selection
The proper selection of packing materials is de-
pendent on the operating conditions of the equipment.
Six parameters of the equipment must be determined
before a proper packing recommendation can be made.
The acronym “STAMPS” is commonly used to desig-
nate these parameters:
S = Size — cross section
T = Temperature — of media being sealed
A = Application — type of equipment (i.e., pumps,
valves, mixers, etc.)
M = Media — material being sealed
P = Pressure — of media being sealed
S = Speed — shaft speed in fpm (pumps only)