Bellow Sealed And Piston Valve With Actuator

• Sude Engineering Corporation (Bangalore)
• Bengaluru

Bellow Sealed And Piston Valve With Actuator

Bellow Sealed Valves are a new breed of Industrial process valves, designed to eliminate Valve leakage and also known as `Zero Leak Valves` or `Emission Free Valves. In these valves, conventional gland packing is supplemented by a metallic Bellow Cartridge joined to the valve bonnet at one end, and the stem at the other end. A bellow is a long accordion-like tube. As the valve stem strokes, the bellow expands or compresses with the stroke movement. There are no sliding or rotating seals through which process fluid can pass. Thus the fluid will enter the valve from the seat of the valve & come in contact with the bellow, but will not come in contact with the stem. Since the stem is the only moving part in the valve, it is a source of potential leakage through the gland due to constant friction caused by the axial movement. In a bellow sealed valve this potential leak is totally avoided due to the metallic bellow which blocks the leak path effectively by not allowing the media to come in contact with the stem and thus the gland. A bellow is the heart of this type of valve. There are two types of bellows: formed and welded leaf. Dangerous fluids are a permanent menace to man and environment. Leakages need to be avoided during operation. The ever-increasing concern for environmental issues has led to use of both leakage and maintenance free bellows sealed valves. Bellows sealed valves guarantee Zero leakage to atmosphere and therefore is an efficient and economic contributor towards security of our surroundings.

Design

• Valve body in cast or forged construction to suit your requirements.
• Spindle with bellow assembly easily replaceable-easy of maintenance.
• Gland packing available as standard in addition to bellow -to arrest any gland leakage in the event of bellow damage.
• Wide choice of bellow materials -including inconnel, Hastalloy, Monel, etc.
• External pressurization of bellow- leading longer bellow life.
• Welding of bellow done under most stringent conditions.
• Bellows selected for higher stroke length than necessary - ensures longer life of bellows.
• Temperature compensation considered as standard during sizing and selection of bellows.

Types

• Formed bellows - which is made with the help of rolling a flat metal sheet into tube with longitudinal fusion welding, in short the tube is hydraulically formed into bellows with rounded and widely faced folds.
• Welded Leaf type bellows - It is a washer like plate of thin metal which are welded together.
• The common difference between Formed bellows and Welded leaf type bellows are as follows.