Senior Flexonics Pathway - Model PB -Expansion Joint

Applications

• Pressure balance are used when pressure thrust needs to be eliminated
• There are two types of PB, with an elbow requires a 90 degree turn in the piping system, and inline can be put in a straight piping system

Operating Range

• Full vacuum to 2000 psig depending on size
• Cryogenic to 1650°F+
• Sizes from 1” NPS to > 240” NPS

Materials

Bellows:

• 3XX Series Stainless Steel
• Nickel Alloys
• Carbon Steel
• Titanium
• Zirconium

PB FIT

• Bellows may be a attached or linked
• to piping anges, pipe, or other typical industrial connections.
• End connections may conform to standards such as ASME B16.5, ASME B36.10, or customer designed.
• Fittings generally not the same at all locations: interface connections may be as noted above. Connections within the assembly are typically to pipe.

PB FORM

• At least Two circular metal bellows, each with 1 or more convolutions. Can have Four bellows.
• Typical dimensions of 2”ANSI NPS to 120” ID. Overall length may vary, typically within the range of 36” to 240”.
• Bellows may include reinforcement or controlling members.
• Convolutions maybe U shaped or toroidal.
• Additional accessories maybe incorporated such as load bearing restraints, movement limiters, protection devices.

PB FUNCTION

• Absorbs movement, primarily axial, but may include small amounts of lateral and/or angular movement.
• Use of controlling members, typically tie rods, is required to cancel the bellows pressure thrust forces on adjacent equipment/piping.
• (some mes referred to as PA loads).
• Movement amplitude varies, typically within the range of 1/4” to 10”.
• Movement frequency may be extreme low cycle (1 per year), or high cyclic (such as vibration at 60 Hz)