Installation and Operation Manual
VA065043 Rev. E
June 2014
4
Section 4: Start-Up
Start-Up
Section 4: Start-Up
1.
When the actuator is first put into service, it should be stroked. This is necessary
because the seals and packings having been stationary, causing them to take
a
"set"
. Therefore, the actuator should be operated through several cycles,
exercising the seals and packings, resulting in a service ready condition.
2.
The actuator speed of operation will be determined by a number of factors including:
a.
Power supply line length
b.
Power supply line size
c.
Power supply line pressure
d.
Control valve and fitting orifice size
e.
Torque requirements of the valve
f.
Size of actuator
g.
Setting of speed controls
h.
Pressure of hydraulic manual override with internal adjustable speed
controls
3.
Due to the interaction of these variables, it is difficult to specify a
"normal"
operating time. Faster operating times may be obtained by using one or more
of the following:
a.
Larger supply lines
b.
Larger control valves
c.
Higher supply pressure (not to exceed minimum operating pressure
of actuator or control components)
d.
Quick exhaust valves
4.
Slower operating times may be obtained by using flow control valves to
meter the exhaust. Excessive exhaust flow metering may cause erratic
operation; incoming supply should not be metered.
Summary of Contents for Bettis Nuclear Series
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