Anti Blowout Stem of Ball Valves
Fireproofing, anti-static and anti-blowout stem are three important design features of ball valves. In this article, we will discuss anti-blowout stem in details.
Anti-blowout stem means that the stem is inserted from inside the valve body to prevent having a blowout. The principle can be explained precisely as follows:
The pressure inside the valve body is always trying to push the stem up when the valve is in the open or closed position. The stem is sealed by o-rings and graphite packing rings, held in position by the stem housing, which is bolted to the body. Therefore, when we remove the gland flange to replace the graphite packing rings, the stem will be held securely by the stem housing even when the valve is under pressure.
Anti-blowout stem means that the stem is inserted from inside the valve body to prevent having a blowout. The principle can be explained precisely as follows:
The pressure inside the valve body is always trying to push the stem up when the valve is in the open or closed position. The stem is sealed by o-rings and graphite packing rings, held in position by the stem housing, which is bolted to the body. Therefore, when we remove the gland flange to replace the graphite packing rings, the stem will be held securely by the stem housing even when the valve is under pressure.
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