Valve bellow a new advanced type of Industrial Process in valves. valve bellows manufactured are mostly recommended for the leakage-free performance hence, it is called as “Zero-Leak Valves” or “Emission Free Valves”.
The bellow cartridge is combined to both the Valve Bonnet and the Valve stalk. The bellow cartridge has a number of convolutions and these convolutions become compressed or expanded depending upon the movement of Valve stem. (In logical term the bellow becomes compressed when the Valve is in the open state and expanded when the Valve is in the closed state). It is important to properly install the Valve into the bodies. The Valve bellow can be sealed to the Valves in two different ways.
In a valve, the bellows can be combined to the Valve stalk at the top and the Valve body on the base. In this case, the metal fluid is contained in the bellow or in the second method the bellow is combined with the Valve stalk at the base and the body on the top. In this case, the metal fluid is carried in the annular section between the Valve Bonnet and bellow (from the outside).
The Valve seal is an important part and forms the heart of the seal Valves bellow. To avoid any twisting of the bellows the Valve must have a stem with linear movement only. This can be obtained using a cover-nut at the Yoke part of the Valve Bonnet. A hand wheel is implemented onto the cover-nut which efficiently transports a turning action of the hand wheel into a straight movement in the Valve stalk. Due to the bellows covering the stem the seal does not contact the stem at all. As the stem is the moving part of the valve it is the source of leakage due to the wear and tear of gland packing. Due to this protection of the stem by the bellows, the valve worked in a leak-free zone.
The long life of the flexible metal Bellow is highly depended upon the method of bellow manufacturing process. At Pliant Bellows are valve bellows manufacturer and global exporter, where we use Stainless steel bellow forming machine to manufacture them by hydroforming process(http://www.bellowexpansionjoints.com/technology ) (Hydroformed bellows). The qualities obtained by the hydroforming process are very excellent as compared to other methods like diaphragm welded bellows or mechanically drawn bellows.