1. what is a globe valve and how the globe valve works?
Globe valve, also known as shut off valve, stop valve, isolating valve, is a mandatory sealing valve, so when the valve is closing, pressure must be applied to the valve disc to force the sealing surface not to leak. When the medium enters the valve from the bottom of the disc, the resistance that the operating force needs to overcome is the friction force between the valve stem and the packing and the thrust generated by the pressure of the medium. The force to close the valve is greater then the force to open the valve, so the diameter of the valve stem should be large, otherwise the valve stem will be bend. When the globe valve is open, the opening height of the valve disc is 25% to 30% of the nominal diameter of the globe valve, the flow rate has reached the maximum, which indicates that the globe valve has reached the fully open position. Therefor, the fully open position of the globe valve should be determined by the stroke of the valve disc.
2. what is the disadvantage of the globe valve?
2.1. the globe valve has a large fluid resistance and requires a large force when opening and closing.
2.2. the globe valve is not suitable for mediums with particles, high viscosity mediums, and easy coking mediums.
2.3. the regulating performance of the globe valve is poor.
3. what is the advantage of the globe valve ?
3.1. the globe valve has a simple structure and is convenient to manufacture and maintain.
3.2. the working stroke of the globe valve is small, and the time for opening and closing is short.
3.3. the globe valve has good sealing performance, small friction between sealing surfaces, and long service life.
According to the position of the stem thread, the globe valve can be divided into external thread globe valve and internal thread globe valve; according to the flow direction of the medium, the globe valve can be divided into straight-through globe valve, oblique globe valve, angle globe valve; according to the sealing type, the globe valve can be divided into packing sealing globe valve, and bellows seal globe valve.