What is a bellows liner? And when to use one?

 

Alpha MahatvarajMetal Bellows

Bellows Liner is an internal sleeve that is used for the following cases,

• To prevent flow induced resonant vibration of bellows due to high flow velocities
• To reduce possibility of erosion from abrasive flow media 
• To limit/ minimize the friction losses and create a smooth flow
• To limit/ decrease the surface temperature of the bellows in high temperature applications

Recommendations for proper design and use of a flow liner?

• The liner material should either be same as the bellows material or suitable for the application.
• When sizing a flow liner proper considerations must be given for the flow velocity, liner length and temperature of the flow media.
•  When there is possibility for reverse flow, or bi-directional flow use of telescoping liner is recommended.
• When used in applications with abrasive media use thicker liner material to prevent failure in the liner and exposing the thinner bellows material to erosion.
• When lateral deflection or angular rotation is present, the liner should be designed with sufficient radial clearance to prevent interference with ID of the bellows through the entire movement range.
• When bellows are installed vertically in the direction of the flow, proper drain holes shall be provided on the liner to drain fluid from being trapped.