Electric valve controller manufacturers generally speaking, when the hot oil system valve is used, the back is fully open, and there is a high degree of polishing and high temperature graphite packing is a good choice for the shut-off valve, they are in various types of steam. Applications are great, steam is part of this world, and heat fluid heat transfer is a popular method.
And if one of the valves is open all the time, other items may be exposed. In special cases, you don't have time to clean and polish. If you pass a dust filler, the dust and dirt on the stem will enter, and the filler will leak.
At the same time, the energy transfer system of the hot fluid is well known and its energy cost is quite high. In some areas, the industry was forced to move to more efficient, reliable, and safe aspects, and in fact they chose steam that was less efficient in hot oil.
Electric valve controller manufacturers introduce the main source of valve thermal fluid system leakage is related to the leakage of the stuffing box, in order to reduce leakage, eliminate all the stuffing box and weld, welding control valve is not always feasible, but can eliminate the filler box.