Clean-In-Place/Steam-In-Place
To perform this procedure, the valve is held in the open
position by applying an air load greater than the CIP/SIP
pressure.
Disassembling Valve
Insure that the valve is not pressurized by following 1.
the Caution at the beginning on the Maintenance
section.
Remove the airload.2.
Remove the actuator (4) by removing the hex bolts (17).3.
Remove the hex jam nut (16), cylinder (14) and lock-4.
washer (15). Caution- beware of spring compression.
Remove the spring and adapter (3).5.
Remove the spacer (11), upper diaphragm plate 6.
(10), and diaphragm (9) from the stem (5). Remove
the lower diaphragm plate (8) and o-rings (19), (20)
where applicable.
Remove the stem (5) from the bottom (inlet) of the 7.
body (1).
Preparing Valve For Assembly
All parts should be cleaned and examined. Damaged
parts should be replaced.
All O-rings should be lubricated with any lubricant that is
compatible with both your process and the o-ring mate-
rial. EPDM o-rings must not be exposed to mineral oil
as it will cause them to swell and make them difcult to
install.
If possible, install a relief valve downstream from the 6.
regulator. Set at about 30% above the control point of
the regulator.
In gas or vapor service, select outlet piping that is at 7.
least one pipe size larger than the inlet.
Operate the regulator within its pressure and temper-8.
ature rating as stamped on the valve nameplate.
If using an air regulator with your MK96A, install a 9.
1/4” tube tting into the 1/4” FNPT air inlet (22) on
the top of the MK96A. Connect an appropriate length
of 1/4” tubing (following local best practice) to the
tube tting and connect the other end to the air pres-
sure regulator at an accessible grade location. Follow
the instructions that come with your air regulator for
proper installation, operation and maintenance.
If using an I/P with your MK96A, connect the I/P air 10.
outlet directly to the MK96A inlet using a threaded
Hex nipple and connect the air line to a tube tting on
the I/P inlet connection. Note: Follow local electrical
code classications and best practice, and make sure
the I/P you have selected has the proper NEMA or IS
rating classication. If not, an alternative might be to
locate the I/P in the nearest Instrumentation/Electri-
cal cabinet with the proper classication. Regardless,
make sure you follow the installation, operation and
maintenance instructions that come with your I/P, and
follow all local best practices, and electrical codes
with regard to wiring and commissioning.
MK96A Start-Up
Fully open the process line block valve downstream 1.
of the regulator using manual air load regulator.
Slowly open the inlet block valve at the regulator 2.
inlet.
Slowly open and close the downstream block valve 3.
several times; this will stroke the valve and conrm
satisfactory operation.
With both block valves open, slowly increase the 4.
airload regulator’s air signal to increase downstream
pressure until it reaches the desired MK96A value.
If using an air regulator with your MK96A, follow 5.
steps 1-3 above. With both block valves open, slowly
increase the dome air signal by adjusting the air
regulator knob (following adjustment instructions in
air regulator installation manual) until the process
pressure downstream of the MK96A reaches the
desired value. Record the air regulator set point in
appropriate documents, or in the control system
information database.
If using an I/P with your MK96A, follow steps 1-3 6.
above. With both block valves open, slowly increase
the dome air pressure to the MK96A inlet by driv-
ing the I/P’s mA input to a value that produces the
desired MK96A outlet pressure. Record the mA set
point value for the PLC, or DCS programmer in the
proper document or in the control system informa-
tion database. Note: Most DCS or PLC HMI programs
allow for manual override of an output signal (manu-
ally adjust 4-20 mA output). If that is not possible,
the I/P wiring (most are two wire devices) can be
disconnected, and a process loop calibrator can be
used to articially drive the I/P to the desired output.
Maintenance
Caution: Make certain that there is no pressure in the
valve before loosening any ttings or joints. The fol-
lowing steps are recommended:
Close the regulator inlet block valve.1.
Allow pressure to bleed off through downstream 2.
piping. Do not attempt to reverse the ow through
the valve by bleeding pressure from the regulator
outlet to the inlet side.
When the upstream and downstream pressure 3.
gauges indicate that all pressure has been removed
from the system, remove the airload or disconnect
the I/P following the devices maintenance manual.
The valve can now be serviced.
Note: refer to the drawing at the end of this document
for description and proper orientation of parts.
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