As manufacturing processes become increasingly precise, the demands placed on instrumentation valves and fittings continue to grow. Alongside material selection, flow control and cleanliness, leak-tight performance is becoming increasingly critical, particularly when handling hazardous or sensitive media.

At NVFCL, we supply FITOK Bellows-Sealed Valves, which use a metal bellows as the stem sealing element. As the stem moves, the bellows compresses and expands to maintain a reliable dynamic seal.

This makes bellows-sealed valves particularly well suited to applications involving toxic, flammable, explosive and hazardous media, as well as systems where pipeline sealing integrity is essential. They are widely used across industries including semiconductor manufacturing, fine chemicals, pharmaceuticals, nuclear power, vacuum systems and low-temperature applications.

What Makes Bellows-Sealed Valves Different?

Ball, needle, diaphragm and bellows-sealed valves all have their place in fluid systems, but their sealing methods and performance can differ significantly.

Traditional packing seals can wear during frequent operation, potentially generating particulates and requiring periodic maintenance. Bellows-sealed valves, on the other hand, use welded metal bellows to create a highly reliable seal without the need for routine packing adjustment.

Their all-metal sealing design also makes them suitable for demanding temperature conditions while maintaining clean flow paths and excellent sealing performance.

Understanding the Bellows-Sealed Valve

The main components of a bellows-sealed valve include the valve body, bellows, stem tip, bonnet nut, stem and operating mechanism.

The bellows is the key sealing component and is typically manufactured from stainless steel to provide durability, corrosion resistance and compatibility with a wide range of media.

FITOK’s SU Series also incorporates a bellows-plus-packing dual-seal configuration. Should the primary bellows seal fail, the secondary packing helps prevent rapid leakage of the process media into the surrounding environment.

Why Choose FITOK Bellows-Sealed Valves?

FITOK’s bellows-sealed valves offer:

• High sealing performance, with a maximum helium leak rate of 4 × 10⁻⁹ std·cm³/s
• 316L stainless steel bellows for chemical compatibility and media purity
• Optional alloy bellows for highly corrosive applications
• Advanced welding processes designed to extend bellows service life
• Multiple valve series supporting working pressures up to 3,500 psig
• Extensive engineering and manufacturing expertise
• Applications across a wide range of critical industries

Source FITOK Bellows-Sealed Valves from NVFCL

As FITOK’s only authorised distributor in the UK & Ireland, NVFCL can provide access to FITOK’s range of high-performance bellows-sealed valves, alongside technical information and application support.

If you’re working with hazardous, corrosive or sensitive media where leak-tight performance is critical, contact the NVFCL team to discuss your requirements and find the right FITOK solution.