2
⅝"
M16
55
75
¾"
M20
65
88
⅞"
M22
110
149
1"
M25
135
183
1⅛"
M30
150
203
1¼"
M30
200
271
1½"
M40
250
339
OPERATION
1. To close the valve and provide isolation,
the actuator (handwheel, bevel gear,
air/hydraulic cylinder or electric actuator)
moves the gate in a linear motion through
the packing box until the gate is seated
against the resilient seat. To open, reverse
the operation and the gate moves up and out
of the packing box, opening the valve port.
2. The valve packing assembly requires
occasional adjustment. Frequency of
adjustment is dependent application
conditions including but not limited to
pressure, temperature and number
of cycles.
3. All valves should be operated within the
design pressure and temperature ranges.
Under no circumstances should the valves
be operated at conditions outside these
parameters.
4. The operator of any valve should have an
understanding of the effects of opening/
closing the valve with regards to its role
in the overall piping system. Operators of
valves under pressure should take Caution
to ensure that the valve is in good operating
condition prior to operating it under
pressure.
5. Certain processes utilize flammable,
caustic and/or otherwise unstable
media. Care should be taken in these
circumstances to ensure the operator is
aware of the specific health and safety risks
associated with that medium. Additionally,
Caution should be taken around all valves
as injury or damage may occur from the
leakage of hot, high pressure and/or caustic
materials from a gasket and/or packing
joint. Packing and/or gasket leaks may
cause external corrosion damage to the
valve.
6. Take care in the manual actuation of
valves used in applications with elevated
temperatures. Ensure the individual
operating the valve does not come
in contact with any hot areas of the
valve. In many elevated temperature
applications, the handwheel may be too hot
to handle, take reasonable preCautions.
Severe temperature applications may
require optional insulation the valves
to protect operators from the heat.
TABLE A - MAX. FLANGE BOLT TORQUE
Bolt size
Torque
Imperial
Metric
lb/ft
Nm
NOTE
Body can be deformed or fractured if flange bolting
is too long or overtorqued.
KEYSTONE
FIGURE PCS17 KNIFE GATE VALVES
INSTRUCTION, OPERATION AND MAINTENANCE MANUAL
7. When operating the valve stand clear of any
moving parts such as the spindle and/or
gate assembly, use of gloves is suggested
when operating manual valves to minimize
the risk of injury.
8. All manually operated valves are designed
for hand input. Do not apply excessive input
torque via pipe wrenches, “cheater bars”,
or other devices. If a manual handwheel
actuated valve is difficult to operate due to
torque requirements, it is recommended
that the valve be supplied with or converted
to a bevel gear, air/hydraulic cylinder or
electric motor actuator.
9. Electric motor actuated valves should be
left in their factory set condition, unless
the system operating parameters dictate
a change. If changes are necessary, they
should be performed in small increments
using the lightest/lowest setting possible
to achieve the desired performance and
then the valve/actuator function inspected.
Excess torque and/or thrust in the motor
settings may damage or lockup the valve.
Never remove a motor operator, gear
operator or manual operating assembly
from a valve while it is pressurized unless
gate has been secured from movement and
lockout/tagout applied per company safety
procedures and policies. The valve must be
completely relieved of all pressure prior to
disassembly or removal from pipeline.
10. Motorized PCS17 valves are position
seated and should never be torque seated.
Do not use the motor torque settings to seat
the valve.
11. Care should be taken to ensure that
electrical motors are wired correctly to the
power source. Incorrect phasing of 3-phase
wiring may cause valve/motor damage.
Cap screw
Stud with nut
FIGURE 3
Wrong
Right
