F
OR
M
ODELS
: JGI, JGM, JGN, JGP
AND
JGQ
S
ECTION
5 - M
AINTENANCE
PAGE 5-36
Type "BTR" Single Acting Seal Set
M
M
M
A
A
A
D
D
D
F
IGURE
5-24 T
YPE
“BTR” S
INGLE
A
CTING
S
EAL
S
ET
Pressure
This set is made up of three rings. It seals in one
direction only. The first ring (pressure side) is
radially cut. The second ring is a tangentially step
cut ring. The first two rings are doweled so the
cuts are staggered from one ring to the other. The
installed total end gap is 1/8 to 5/32 inches (3 to 4
mm) for Teflon and 7/32 to 1/4 inches (5 to 6 mm)
for bronze and PEEK. Maintain the end gap by
adjusting ring gap or replacing the ring. The third
ring is called a back-up ring and is radially cut. The bore in this ring is larger than the rod
diameter. This allows the radial joints to be tight together forming a gas seal. No dowel is
necessary for this ring.
Type “AL” Double Acting
Seal Set
A
A
A
A
A
A
F
IGURE
5-25 T
YPE
“AL” D
OUBLE
A
CTING
S
EAL
S
ET
Pressure
This set is made up of five Teflon rings.
The center three are radial cut and the
two outboard rings are step-tangent cut.
The last two rings on each end are dow-
eled together to stagger the cuts. The
center ring, along with the two adjacent
rings, form a wedge that overcomes rod
friction and forces the set to have con-
stant contact against both groove faces during either direction of rod travel. The installed
total end gap is 1/8 to 5/32 inches (3 to 4 mm) for rings 1,2, 4 and 5. This ring set is designed
for gas purge applications. Maintain end gap by adjusting ring gap or replacing the ring. “AL”
rings must be centered when installed in the packing case. Since the AL ring set seals
end-to-end in the cup and with the low lube rate, newly installed rings could run virtually dry
for the first few hours of operation. To avoid damage to the rings and rod, copiously oil the
ring set during installation, before the rod is installed. Only use the same lubricant that is
used in the force feed lube system.
F
IGURE
5-26 T
YPE
“BD”
D
OUBLE
A
CTING
V
V
V
Type "BD" Double Acting Seal Set
This set consists of two tangentially step cut rings. The
rings are doweled so the tangential cuts are staggered
from one ring to the other. The installed total end gap
is 1/8 to 5/32 inches (3 to 4 mm) for Teflon and 7/32
to1/4 inches (5 to 6 mm) for bronze and PEEK. Main-
tain end gap by adjusting ring gap or replacing the
ring. The set is double acting in that it will seal in either
direction. It is used in cylinders operating near atmo-
spheric pressure to prevent air from entering the cylin-
der. Install with the match mark letters facing the pressure.