6
Penberthy
SErIES 500 and 700 OS&Y armOrEd gagEcOckS
InstallatIon, operatIon and maIntenance InstructIons
7.1 Preventative maintenance
On all installations, the following items should
be evaluated regularly by the user for purposes
of maintenance:
1. Leakage between the body and the yoke.
2. Leakage around stem area.
3. Internal stem leak.
4. Leakage around union connection.
5. Leakage around stuffing box connection,
if applicable.
6. Internal or external corrosion.
The user must determine an appropriate
maintenance schedule necessary for his or
her specific application, upon evaluation of
their own operating experience. realistic
maintenance schedules can only be determined
with full knowledge of the services and
application situation involved.
7.2 re-certification program (Fe gagecocks)
Stem packing material may wear with extensive
operation of the gagecock. Over time leak
paths may develop that cause the emission
rate to exceed 5 ppm. Including gagecock
re-certification in gagecock maintenance
schedules is recommended. For a nominal
service charge, gagecocks can be returned
to the factory for testing. In most instances,
if leaks above 5 ppm are found, Emerson can
replace the packing, retest the gagecock and
return the gagecock for service.
contact your distributor for price information.
7.3 ball check shut-off
saFety InstruCtIOns
Ball checks, when installed, may fail to seat due
to corrosion of the ball or seat, foreign material
in ball chamber or viscous material in the ball
chamber. A routine operational test of the ball
check can prevent significant seepage of liquid
in the event of glass breakage.
an operational check can be performed on the
gagecock ball check by closing both the upper
and lower gagecock stems completely. drain
contents from and relieve pressure on liquid
gage to an appropriate safe container/area.
note:
some loss of process fluid to the drain
line is expected with this test procedure.
WarnInG
Use only qualified, experienced personnel who are
familiar with gagecock equipment and thoroughly
understand the implications of the tables and
all the instructions. DO NOT proceed with any
maintenance unless the gagecock assembly has
been relieved of all pressure or vacuum, has been
allowed to reach ambient temperature, and has
been drained or purged of all fluids. Failure to do
so can cause serious personal injury and property
damage.
With the drain line in place, open the BOTTOm
gagecock as rapidly as possible. Listen for
'click' sound, which will indicate that the ball
has seated. If possible, observe the quantity
of flow from the drain line. Flow should either
stop completely or be no greater than single
drips (no solid stream). close lower gagecock.
repeat above procedure for UPPEr gagecock.
There must be a pressure differential of at least
5 psig (35 kPa) for the above procedure to work
properly.
If the above procedure is not successful, the
only alternative is to isolate the gage and
gagecock assembly from the vessel or to shut
the process down completely. disassemble the
gagecock as outlined in Section 8.1 using the
exploded parts drawings in Sections 12 and 13
as a reference. Visibly inspect ball check and
ball seats in the gagecock body. remove any
foreign matter and/or replace with new ball
checks if inspection indicates this is required.
If the ball seat is damaged, consider replacing
the gagecock or the seat. reassemble
gagecocks as outlined in Section 8.2.
7.4 troubleshooting
leakage between the body and yoke
can often
be stopped by tightening the yoke and screws.
If leakage persists, the yoke gasket should be
replaced by following steps 1) and 2) of the
disassembly and 4) and 5) of the reassembly
instructions. The models 550 and 750 Fugitive
Emission gagecock use an O-ring to seal the
yoke to the body. Follow steps 1) and 2) of the
disassembly and 4) and 5) of the reassembly
instruction to replace O-ring.
stem packing leakage
can often be stopped by
tightening the stem packing follower screws.
If leakage persists, the stem packing should
be replaced by following steps 1) through 5)
of the disassembly and 1) through 6) of the
reassembly instructions. If the gagecock set is
equipped with grafoil
®
stem packing the leak
may be stopped by adding an additional ring
of packing in the packing stuffing box. Turn
the handwheel counterclockwise until it seats
against the stem packing retainer. remove
the stem packing follower screws. Slide the
stem packing follower and gland away from the
packing stuffing box. Insert an additional ring
of packing in the stuffing box. Slide the stem
packing gland and follower down against the
packing and tighten the stem packing follower
screws.
