Swagelok – SS‑BNS4‑C – 316L SS High‑Purity Bellows‑Sealed Pneumatic Valve

The Swagelok SS‑BNS4‑C is a high-purity, bellows-sealed valve from the BN series, engineered for ultra-clean fluid and gas control in demanding semiconductor, pharmaceutical, and aerospace applications. Featuring a pneumatic actuator that returns to a normally-closed position, it maintains a packless, all-metal seal to atmosphere, effectively eliminating leakage risks. Precision-engineered from 316L stainless steel, it’s ideal for UHP systems up to 200 °F (93°C) and pressures up to 125 psig (8.6 bar)  .

Key Features:

• Model: SS‑BNS4‑C

• Manufacturer: Swagelok (BN Series)  

• Body Material: 316L stainless steel

• Bellows Material: Series BN (321 SS alloy)  

• Connection Size: 1/4″ Swagelok tube fittings (@ both ends)  

• Actuator Type: Pneumatic, spring-return, normally closed  

• Flow Pattern: Straight-through, 2-way valve; Cv ≈ 0.3  

• Temperature Range: –40°F to +200°F (–40°C to +93°C)  

• Pressure Rating: 125 psig @ 100°F (8.6 bar @ 37°C)  

• Stem Tip: PCTFE for reliable sealing  

• Cleaning & Packaging: SC‑11 cleaning for high-purity service  

• Sealing: Packless, welded metal bellows eliminates external leakage