FIELD OF THE INVENTION
The present invention relates to a Position transmitter mounting for HP Control Valve Servomotor.
BACKGROUND OF THE INVENTION
In the existing 500/600 MW TG sets, position of HP Control Valve is measured through a rope type position through which observed impedance value depending on Valve stroke is fed to a controller card which generates corresponding electrical signal and later converted into actual physical measurement based on calibration. Thus direct measurement of Valve stroke in electrical signal form is not possible in existing system and those measurement is not very accurate. Further, Calibration of resultant electrical signal with corresponding actual stroke value in difficult to match.
OBJECTS OF THE INVENTION
It is therefore an object of the invention to propose a Position transmitter mounting for HP Control Valve Servomotor.

Another object of the invention is to propose a Position transmitter mounting for HP Control Valve Servomotor, which calibration of electrical signal is done easily and matching with actual stroke of the valve.
A still another object of the invention is to propose a Position transmitter mounting for HP Control Valve Servomotor which holds the position transmitter within the harsh operating environment and protects it from mechanical jerks and higher ambient temperature of steam turbine.
SUMMARY OF THE INVENTION
Accordingly, there is provided a Position transmitter mounting for HP Control Valve Servomotor. The position of HP Control Valve of Steam Turbine in steam turbine can be accurately measured and converted to electrical signal for transmitting to the Control room where the value of physical value stroke value is displayed and used in a Governing system. In particular the present invention relates to a method of measuring Valve stroke of HP Control valve in electrical form as well as in mechanical scale.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1A : Sectional view of Position transmitter mounting marked with major items along with Section A-A.
Figure 1B : Sectional view of Position transmitter mounting marked with major items along with view X.

Figure 1C: Sectional view of Position transmitter mounting marked with major items along with view Y.
Figure 2 : 3-D model of the Position transmitter mounting marked with major items.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
Figure 1A shows sectional view of the Position transmitter mounting marked with major items along with Section A-A. Figure 1B shows secti8onal view of Position transmitter mounting marked with major items along with view X. Figure 1C shows Sectional view of Position transmitter mounting marked with major items along with view Y and Figure 2 shows 3D model of the Position transmitter mounting marked with major items. All the major components have been marked in the above referred figures. Details of major components of the inventive mounting device for Position transmitter and their functions are described below:
1. Support (01): The support is mounted on the existing yoke of HP Control valve
through bolts and nuts. The support is designed in such a way that it holds the
position transmitter in such a position that movement of valve stroke is
transferred through existing Lever to the linear motion of magnet via control arm
of position transmitter.
2. Insulation plate (0.2) It shields the position transmitter thermally from the
higher ambient temperature of the support.

3. Position Transmitter (03): It measures the valve stroke of HP Control valve. The
linear motion is transmitted to the magnet of the position transmitter. Movement
of the magnet over position transmitter generates current signal according to the
position of magnet and this current signal is transmitted to the control room.
Current signal of magnet is linked with the position of the magnet which is
calibrated corresponding to closed position and full open position of the valve.
Further local scale also shows the measurement of valve stroke. In the control room, physical stroke of control valve is displayed as per calibration of corresponding current signal.
4. Control arm (04): Control arm is the linkage between the position transmitter and Control Valve spindle. It is connected via lever of control valve spindle and transmits the linear movement of Control valve spindle parallel to linear movement of Magnet of position transmitter. It has spherical joint at one end to take care of slight eccentricity in movement.
5. Protection cover (05): It protects the position transmitter from impact of external bodies and also from dust and foreign particles. Further, it provides protection during transport.

WE CLAIM :
1. A device for Position transmitter mounting for HP Control Valve Servomotor, comprising a Control arm, a support an insulation plate and a magnet, wherein the linear stroke of the control valve can be transmitted to generate a movement of the magnet via a lever through the Control arm over the position transmitter, which allows mechanical reading of the valve stroke value as well as generation of corresponding electrical signal, wherein the electrical signal is calibrated to mechanical stroke value and displayed in a control room as stroke of respective Control valve.
2. The device as claimed in claim 1 wherein the insulation plate keeps the associated electronic instruments away from direct contact of higher temperature of the operating environment.
3. The device as claimed in claim 1, wherein the device maintains the position transmitter horizontal and co-axial with the stroke of the Control valve.