Bellows Gate Valve

Product Advantages

● Ideal for Hazardous Media: Prevents leakage of toxic, flammable, or corrosive fluids.
● Extended Service Life: Bellows design reduces stem wear and minimizes maintenance.
● High Temperature & Steam Resistant: Excellent performance in thermal oil and steam systems.
● ● Energy Saving & Safe Operation: Zero leakage reduces media loss and enhances workplace safety.
● Stable Shut-Off: Wedge gate design ensures reliable sealing over long-term use.

Size Range

● NPS 1″ – 12″ / DN25 – DN300

Pressure Rating

● PN16 / PN25

Standards

● Design Standard: EN 13709 / API 600 / ASME B16.34
● Test Standard: EN 12266 / API 598
● Flange Standard: EN 1092-1 / ASME B16.5

Industry Applications

● Chemical processing systems
● Steam distribution & condensate systems
● Petrochemical units & refinery pipelines
● Thermal oil and high-temperature fluid systems
● Vacuum and negative pressure pipelines
● Hazardous and environmentally sensitive media

FAQs

1. What does the bellows actually protect against that standard packing doesn’t?
Standard packing relies on compression around the stem, which wears down and can develop a slow leak over years of operation. A welded stainless steel bellows fully isolates the stem from the atmosphere, so there’s no leak path at all — even if the packing eventually wears, the bellows keeps sealing independently.

2. Why does this valve also include graphite packing if the bellows already seals the stem?
The packing acts as a backup seal in case the bellows itself is ever damaged, so a single point of failure doesn’t turn into an immediate external leak — it’s a safety margin, not a sign the bellows alone is insufficient.

3. What does “anti-blowout stem” protect against specifically?
It mechanically retains the stem inside the body so pressure alone can’t force it out, even if the bonnet connection is compromised — a real risk in high-pressure or thermal-cycling service where seals can loosen over time.

4. Is a solid wedge the right disc choice for this valve, or should I look at a flexible wedge instead?
A solid wedge is simpler and holds up well where temperature stays fairly stable; a flexible wedge self-adjusts to minor seat misalignment from thermal expansion, which matters more in steam or thermal oil service with frequent temperature swings — worth confirming against your process conditions if cycling is frequent.

5. Can this valve be used in vacuum or negative-pressure service, not just high pressure?
Yes — the same sealed-stem design that prevents outward leakage under pressure also prevents air from being drawn in under vacuum, which is why it’s specified for vacuum and negative-pressure pipelines as well as pressurized hazardous media lines.