BLA POWER PVT. LTD WOODWARD 505 GOVERNOR VALVE / ACTUATOR CALIBRATION &TEST LALIT SINGH Sr. Engineer C&I Dept.
May 26, 2015
B L A P O W E R P V T . L T D
WOODWARD 505 GOVERNOR VALVE / ACTUATOR
CALIBRATION &TEST
LALIT SINGHSr. EngineerC&I Dept.
WHY CALIBRATION/STROKE CHECKING REQUIRED
Before initial operation or after a turbine overhaul where any
actuator or valve
travel may have been affected, the below Valve Calibration
procedure should be
followed to insure that the 505 is correctly calibrated to the
turbine control
valve(s). When calibration is complete, 0 to 100% actuator
position as displayed
by the 505 must equal 0 to 100% actual valve travel.
BEFORE START PROCEDURE
Before calibrating or testing, the unit must be tripped and the steam
supply removed. This is to ensure that opening the control valve (s)
will not allow steam into the turbine. Overspeed sensing and its
relay are disabled during this process. Overspeeding the turbine
may cause damage to turbine and can cause severe injury or death
to personnel. STEAM TO THE TURBINE MUST BE SHUT OFF BY
OTHER MEANS DURING THIS PROCESS.
505 KEY PAD AND DISPLAY
IN WOODWARD STEP-1
The 505’s Emergency shutdown contact input must be closed or
jumpered throughout this procedure (All Turbine Trip
Interlock From DCS Side will by pass after that setting jumper as mention
below TB’s after that DCS will not be able to turbine trip)
JUMPERE DETAIL IN TSP PANEL
Jumper J1:- In TSP Panel DIT-1 & DIT-2 .
Jumper J2:- In TSP Panel DIT-5 & DIT-6
Jumper J3:- In TSP Panel DIT-7 & DIT-8
Jumper J4:- In TSP Panel DIT-11 & DIT-12
Jumper J5:- In TSP Panel DIT-13 & DIT-14
Jumper J6:- In TSP Panel DIT-17 & DIT-18
IN WOODWARD STEP-2
Execute a system RESET command (Press the 505 “Reset”
key)
Press the 505’s front panel “Emergency Shutdown” button.
Press the ‘ACT’ key then the SCROLL DOWN key until the
“Stroke Actuators - Dsbled, Steam Must be Off” message
appears. (Verify that the turbine’s steam supply has been
shutoff before by an external Trip and Throttle valve.)
IN WOODWARD STEP-3
Press the “YES” key (This will cause the screen to
display a “Stroke to Min - Enabled, Min Curr
Adjust *XX.XX” message).
Press the “YES” key to enable this mode or the
“Scroll Down Arrow” to step to the mode desired
IN WOODWARD STEP-4
Stroke to Min - Enabld, Min Curr Adjust * XXX.XX — Press YES
to force the actuator output to the minimum stop. The message will
display ‘At Min’ and the actuator output current will move to its
minimum setting. The minimum current value can be adjusted only
when the ‘at sign’ (@) is on the bottom line of the display. Press the
SELECT key to move the @ symbol between the top and bottom lines.
Press the ADJ UP or DOWN keys to change the 0% actuator current
level. Press the SCROLL DOWN ARROW to step the next desired
mode, or the “CLEAR” key twice to save changes, and exit Calibration
mode.
IN WOODWARD STEP-5
Stroke to Max - Enabld, Max Curr Adjust * XXX.XX— Press
YES to force the actuator output to the maximum stop. The message
will display ‘At Max’ and the actuator output current will move to its
maximum setting. The maximum current value can be adjusted only
when the ‘at sign’ (@) is on the bottom line of the display. Press the
SELECT key to move the @ symbol between the top and bottom
lines. Press the ADJ UP or DOWN keys to change the 100% actuator
current DOWN ARROW to step the next desired mode, or the
“CLEAR” key twice to save changes and exit Calibration mode.
IN WOODWARD STEP-6
Manually Adjust - Enabld, Stroke Valve XXX.XX — Press the ADJ UP, ADJ DOWN keys
from this screen to move the valve’s output current between 0-100% at a 5%/second rate.
This allows both the actuator and valve to be tested for binding, play, resolution, linearity,
and repeatability.
Press the “YES” key at any time to allow a setting to be directly ‘Entered’. The message
will display ‘Manual’ when the ENTER mode is allowed. When in the ‘Manual’ mode, press
the “ENTER” key, enter the setting desired, then press the “ENTER” key again. This will
step the actuator output to a specific position instantly. Press the “ADJ UP/DOWN” or “No”
keys at any time to switch back to the “Enabld” mode.
When calibration is complete, 0 to 100% valve position as displayed by the 505 must
equal 0 to 100% actual valve travel. Press the SCROLL DOWN ARROW to step the next
desired mode, or the “CLEAR” key twice to save changes and exit Calibration mode.
INFORMATION
Press the CLEAR key twice to permanently
save any minimum or maximum actuator
settings into the 505. If variables are tuned or
changed but not stored in EEPROM by pressing
the CLEAR key twice, then those changes will be
lost if power is removed from the control or if
the control receives a CPU reset.
FLOW CHART
SCREEN DETAIL
Screen 3 show only when the unit is shut down. Screen 4,5 and 6
show only when stroke actuator is set to yes .
The asterisk (*) denotes a tunable parameter . To adjust this
parameter , the “@” symbol must be on the display line containing
the asterisk . The @ symbol is moved with the selection key .
Note :- If change are made to min or max current values they
can be recoded on the program mode worksheet under the
“Driver Configuration” header .
STROKE ACTUATOR MESSAGES
MESSAGE MEANING
Dsbld Stroke actuators function is disabled
Enabld Stroke actuators function is enabled
At Min Actuator output is set to the minimum
value ( 0% )
At Max Actuator output is set to the maximum
value ( 100% )
Manual Actuator output is in manual mode
VOITH I/H CONVERTER OR CPC
Voith electro hydraulic I/H converters adjust hydraulic positioning
cylinders by means of a pilot valve. The positioning cylinders operate
a valve that controls the mass flow needed to drive machinery. Voith
I/H converters ensure very precise and highly dynamic control of the
mass flow.
I/H converters change a constant input pressure into a variable
output pressure. A standard 0/4 – 20 mA with respect to 2- 4 Kg/Cm2
O/P Hydraulic Pressure . The major components of the I/H converter
are a hydraulic unit and a force-controlled electromagnet.
WORKING PRINCIPALA set signal w = 4...20 mA generates a magnetic force FMag in the VRM, the limits of which can be
adjusted by means of the X0 and X1 potentiometers and which is then transmitted onto the control
piston via tappet. The hydraulic force FHyd being proportional to the output signal pressure PA acts
against this force. In the case of the two forces being equal, the control piston is positioned in the
“hydraulic center” as shown in fig. and the output signal pressure PA corresponds to the set signal.
In the “hydraulic center“ position the control piston performs minimum oscillating movements in
the area of the guiding edges P→PA and PA→T, in order to keep the output pressure PA on the value
set by FMag. When increasing the set signal and thus FMag from this condition, the control piston
position changes and thus connects the output pressure PA to the feed pressure P and blocks PA
towards the tank return line T1and T2. Now pressure PA will increase until the same has returned
the control piston to the “hydraulic center“ and PA corresponds to the new set signal. The spring
force FFed of the control spring generates a force-offset in order to guarantee the I/H converter
function for output pressures of approx. 0 bar, too.
FUNCTION
Solenoid-force control generates a magnetic force of FMag in a 24V d.c. solenoid.
This magnetic force is proportional to the 0/4 – 20 mA input signal , the limits are
configured using the X0 and X1 parameters. The electronic control, magnetic flux
measurement, engineering design of the magnet and the hydraulic pilot control
together form a dynamic functional unit that is practically free of hysteresis.
The control magnet applies the force FMag to the control piston. This in turn
counteracts hydraulic force FHydr as generated by the pressure at output A over the
cross-sectional area of the control piston .
As a result of this regulation, the output line of the actuator always receives the
exact required pressure and the oil quantity for positioning the steam or fuel valves.
CALIBRATION
Due to unintentional maladjustment of the parameters or changed operating
conditions, new setting of one or both parameters may become necessary. We
recommend to document adjustment of the parameters as well as the set values. The
parameters are adjusted by means of potentiometers X0 and X1.
X0 - With help of potentiometer X0 the minimum output pressure PA min is adjusted at
a set point of 4 mA. Pressure increase by turning the potentiometer clockwise.
X1 - With help of potentiometer X1 the maximum output pressure PA max is adjusted at
a set point of 20 mA. Pressure increase by turning the potentiometer clockwise.
Note:-X1 should be adjusted before X0. The X1- adjustment influences the
adjustment of X0
I/P CURRENT V/S O/P PRESSURE
S .N o.
I /P C omm.
(0-100% wrt 4-
20mA )
O /P P ress. K g/C m2
I nc.
O /P P ress. K g/C m2
D ec.
1 0 2 22 10 2.18 2.193 20 2.36 2.374 30 2.55 2.575 40 2.74 2.766 50 2.94 2.967 60 3.14 2.168 70 3.34 3.369 80 3.57 3.5710 90 3.76 3.7711 100 3.99 3.99
Thank You