Bellows Valves with Secondary Packing—U Series
Swagelok® U series bellows-sealed valves enhance reliability, versatility, and safety—with a secondary containment system that prevents leaks to atmosphere even if the primary seal fails.
Stem Tip Material
Up to 2500 psig (172 bar)
–20 to 1200°F (–28 to 648°C)
0.36 to 5.3
316 stainless steel
316 stainless steel, PCTFE,
Swagelok tube fitting, female VCR® face seal fitting, tube socket weld, tube butt weld
1/4 to 3/4 in.; 6 to 12 mm
0.11 to 1.46 in.3 (1.8 to 23.9 cm3)
- Gasketed or welded body-to-bellows seals
- Stem tips for shutoff or regulating service
- Panel, bottom, and side mounting available
- Bar handle and pneumatic actuation available.
- Upper packing provides secondary containment as backup to primary seal.
- Acme power transmission threads enable low operating torque.
- 4U, 6U, and 8U series contain conventional bellows (system pressure acts on inside
of bellows); 12U and 12UA series contain inverted bellows (system pressure acts
on outside of bellows).
- Straight- and angle-pattern valves
Every U series bellows valve is factory vacuum tested with helium at room temperature
for 5 s to a maximum leak rate of 4 × 10–9
/s at the
seat, envelope, and all seals.
Cleaning and Packaging
- Swagelok U series bellows valves with VCR end connections are processed in accordance
with Swagelok Special Cleaning and Packaging (SC-11) to ensure compliance with product
cleanliness requirements stated in ASTM G93 Level C.
- Swagelok U series bellows valves with other end connections are processed in accordance
with Swagelok Standard Cleaning and Packaging (SC-10); special cleaning and packaging
are available as an option.
- High-Temperature Model
- Nickel-based lubricant prevents seizing of actuator threads.
- Valve rating extends to:
- 1000°F (537°C) for valves with VCR fittings.
- 1200°F (648°C) for valves with Swagelok tube fittings.
- Low-Temperature Model
- PTFE secondary packing for temperatures
- from –325 to 400°F (–200 to 204°C).
- Alloy 600 bellows
- Normally closed, normally open, and double acting actuation modes
- Reliable piston design for enhanced cycle life
- Low actuation pressures
- Aluminum and stainless steel components
Pneumatic Actuator Options and Accessories
- Pneumatic Actuator Microswitches
- Signal OPEN or CLOSED position of valve to panel or process controller
- Factory assembled on 4U, 6U, and 8U series valves
- Microswitch kits for field assembly.
Stem tip/adapter kits, bellows kits, and gasket kits are available for UG, URG,
and UK series valves. Download the Swagelok Bellows-Sealed Valve Maintenance Kits