5
Penberthy
SerieS N2/K2 Tubular gagecocKS
InstallatIon, operatIon and maIntenance InstructIons
6 OPeratIOn
before initializing gagecock operation, check
that all installation procedures have been
completed. use only qualified, experienced
personnel who are familiar with tubular
gagecock equipment and thoroughly
understand the implications of the tables and
all the instructions. check to determine that all
connections are pressure tight.
warnInG
Gagecock installations should be brought
into service slowly. The tubular glass used
in gagecocks is tempered and can withstand
minimal thermal shock and mechanical stress.
Gagecocks should be opened slightly, and the
gagecock assembly temperature and pressure
allowed to slowly equalize. If the gagecocks are
equipped with ball checks, the gagecocks must
be opened all the way after the pressure and
temperature have equalized to permit operation
of the automatic ball check in the event of tubular
glass failure. Failure to follow the recommended
operating procedures can result in severe
personal injury or property damage.
6.1 hydrostatic test
Take all precautions necessary to handle
the possibility of leakage during the test.
Hydrostatic pressure test all installations to
100 psig (690 kPa) and correct any leakage
before proceeding.
7 MaIntenanCe
warnInG
Use only qualified, experienced personnel who
are familiar with tubular 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.
The user must create maintenance schedules,
safety manuals and inspection details for each
gagecock. These will be based upon the users
own operating experience with their specific
application. realistic maintenance schedules
can only be determined with full knowledge of
the services and application situations involved.
During system shutdown, the gagecocks should
be left open to permit the tubular glass to lose
pressure and cool with the rest of the system.
Failure to leave the gagecocks open during
system shutdown may trap high-pressure fluid
in the tubular glass.
7.1 Preventative maintenance
on all installations the following items should
be evaluated regularly by the user for purposes
of maintenance:
1. leakage around stem area
2. internal stem leak
3. leakage around stuffing box connection
4. internal or external corrosion
The user must determine an appropriate
maintenance schedule necessary for his or her
own specific application, upon evaluation of
his or her own operating experience. realistic
maintenance schedules can only be determined
with full knowledge of the services and
application situation involved.
7.2 ball check shut-off
safety instructions
ball checks, when installed, may fail to seat
due to corrosion of the ball or seat, foreign or
viscous material in the ball chamber. a routine
operational test of the ball check can prevent
significant seepage of fluid in the event of
tubular 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 tubular
glass 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 tubular 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 drain line in place, open 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 tubular
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 drawing in Section 11 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 (if it is removable). reassemble
gagecocks as outlined in Section 8.2.
