AMAYZEN139: Construction of ENV-116G Turbine 2

6. Emergency Stop and Governor Valve

The emergency stop valve is situated upper position and the governor valve is situated down position.

The emergency stop valve has two distinct purposes. First, to control throttling of steam when starting and bring the turbine up to speed; second, to act as quick-closing valve when tripped by hand or remote=trip, and as emergency stop valve when tripped automatically by safety device such as over speed trip, back pressure trip, low oil pressure trip.
The spindle and the spring seat is threaded, the spring is compressed by the spring seat, and the pin on the spring seat is set by lever which is connected to the trip cylinder.
The trip cylinder consist of the piston rod, the piston, the spring and the cylinder body. When the oil pressure in the cylinder body decrease, the piston is moved upward by the spring force together with the piston rod and the lever. At same time the pin on the spring seat is severed from the lever, so the spring seat, the spindle, the pilot disc and the disc are forced down by the spring.
Thus, the emergency stop valve, the piston is situated at reset position by the oil pressure in thecylinder body. By hand the hand wheel is turned to the right, and by turning th hand wheel to the left is opened the emergency stop valve.
The disc must be open after the pilot disc and being small deference pressure on the disc upper and lower face, by means of restricting the steam flow with the adjusting disc.

The Governor valve position is determined by movement of the governor and the governor valve controls the flow of steam to the steam chest.
The governor valve consist of the adjusting disc, the disc guide and the stem, and is the balance type. The adjusting disc is guided by the bush and is controlled by the stem on account of the governor movement. The stem flows inter the steam chest through the port on the diec guide.

The governing shaft of the governor and the governor valve stem are connected with the governor link. and that is consisted of ball joints, a lever, rods and fulcrum pins. The link conveys smoothly the movement of the governor to the governor valve.
The link needs the adjustment for reassembly that the clearance between the governor valve stem and the stopper of the valve seat is about 2mm when the governor is full shutting. Changing the position of the pin needs in case the steam flow of the governor valve is reduced at full opening of the governor.