F
IGURE
5-27 T
YPE
“3RWS” W
IPER
S
ET
F
OR
M
ODELS
: JGI, JGM, JGN, JGP
AND
JGQ
S
ECTION
5 - M
AINTENANCE
PAGE 5-37
Type "3RWS" Oil Wiper Set
The three cast iron rings in this set are
radially cut and doweled to stagger the
cuts from one ring to the other. They
keep crankcase oil out of the packing
and cylinder. Assemble with the blank
face towards the oil (crankcase) and
the slotted side towards the pressure
packing. Total end gap installed is 3/16
to 7/32 in. (5 to 6 mm). Maintain end gap by adjusting ring gap or replacing the ring.
Typical Arrangement of Piston Rod Packing Rings
The general arrangement of the oil supply, seal ring and vent locations is shown below:
The oil wiper rings and a seal ring set are carried on a separate diaphragm in the crosshead
guide when a “two compartment distance piece” is supplied.
NOTE: REFER TO THE PACKING ASSEMBLY IN THE ARIEL PARTS BOOK. SEE FIG-
URE 2-4 ON PAGE 2-13 FOR PACKING TUBING AND DISTANCE PIECE VENT-
ING AND FIGURE 2-5 ON PAGE 2-14 FOR PACKING LUBRICATION AND
VENTING.
Piston Rod Packing Ring Material
In the past, bronze was the standard material for Ariel packing rings. Bronze, however, is
unsatisfactory for sour gas service, (hydrogen sulfide in the gas). PEEK, cast iron and Teflon
provide outstanding service with sour gas, and since they perform equally well with sweet
gas, they are now the standard materials.
A typical packing will have a PEEK pressure breaker, Teflon/cast iron single acting rings, all
Teflon double acting rings, and a cast iron wiper set. The Teflon is glass reinforced and
impregnated with molybdenum disulfide. This provides a strong, slick material to reduce fric-
tion and wear.
PRESSURE SIDE
PRESS
URE
BREAKER RING
1-SINGLE SEAL RING SET
OIL SUPPLY
3-SINGLE SEAL RING SET
S
PRIMARY V
E
NT
DO
UBLE SEAL RI
NG
SET
WI
P
E
R
S
E
T
CRANKCASE
S
IDE