ramanathan,

Check the Hyspan Barco website for a number of flexible joint options,

www.hyspan.com

The Barco ball joints could allow more rotation than a slip-joint, if that is required. The O**o State University Powerhouse has a pair of 10" Barco ball joints in a configuration similar to a tied universal assembly. This accomodates the steam piping differential movements between the 200 psi steam main header and the tunnel entry point for steam service line to their fieldhouse. Ball joint operating forces are affected by friction and lubrication, like the slip joint operation.

The limited space inside a tunnel means the piping linear expansion is taken in the Dresser type slip joints, and the corners are relatively fixed in position. The above ground steam lines are usually arranged so that there is clearance at corners for the expansion to bend the piping, loops or flexible joints. The choice to use slip joint, ball joint, bellows joint, or expansion loop, will depend on expansion, fluid service, reliability, cost, loads, and available space constraints, among others.