What are the basic reasons of having rubber expansion joints within the piping with or without control units?
Just need to know that if at one place they are without any control units, what are the reasons?
Rubber Expansion Joins with & without Control Units
Re: Rubber Expansion Joins with & without Control Units
Control units on expansion bellows are used where there is a lack of proper pipe anchors - the initial surge of the pump may cause hyper extension.
They are also used where there is a control on lateral movement is applied.
Or where proper piping supports are not available as rubber expansion joints are not designed to take any proper weight.
They are also used where there is a control on lateral movement is applied.
Or where proper piping supports are not available as rubber expansion joints are not designed to take any proper weight.
Re: Rubber Expansion Joins with & without Control Units
The application of control units is also considered in wide range of operating temperature as well where excessive expansion is expected even when there is proper piping anchor is available. However, application of control units near the pumps is common.
Re: Rubber Expansion Joins with & without Control Units
Control units are installed on rubber expansion joints whenever the surrounding piping system cannot safely absorb internal pressure thrust or restrict extreme pipe movements.
Absence of Fixed Main Anchors: When the piping layout lacks heavy structural anchors to hold the pipe against internal pressure thrust, tie rods are required to mechanically bridge the gap and absorb that outward hydraulic force.
High Operating Pressures: In systems where operating pressures generate a high thrust force that exceeds the natural rigidity or friction resistance of the piping, preventing the rubber bellows from over-elongating or blowing out.
Un-guided or Unsupported Runs: When adjacent pipes lack proper directional alignment guides, limit rods prevent the joint from twisting, over-compressing, or stretching past its maximum allowable design limits.
Pumps and Dynamic Surge Conditions: On unanchored equipment connections, liquid lines, or systems prone to water hammer, pressure surges, or rapid startup and shutdown cycles that can violently jerk the piping.
Suspended or Vertical Piping: In vertical lines or suspended overhead racks where gravity and dynamic loads place constant tensile stress on the expansion joint, requiring rods to carry the weight and prevent separation.
Using control units effectively transforms the expansion joint into a self-restrained unit, protecting the system from catastrophic separation when ideal structural anchoring is impractical or impossible to install.
Absence of Fixed Main Anchors: When the piping layout lacks heavy structural anchors to hold the pipe against internal pressure thrust, tie rods are required to mechanically bridge the gap and absorb that outward hydraulic force.
High Operating Pressures: In systems where operating pressures generate a high thrust force that exceeds the natural rigidity or friction resistance of the piping, preventing the rubber bellows from over-elongating or blowing out.
Un-guided or Unsupported Runs: When adjacent pipes lack proper directional alignment guides, limit rods prevent the joint from twisting, over-compressing, or stretching past its maximum allowable design limits.
Pumps and Dynamic Surge Conditions: On unanchored equipment connections, liquid lines, or systems prone to water hammer, pressure surges, or rapid startup and shutdown cycles that can violently jerk the piping.
Suspended or Vertical Piping: In vertical lines or suspended overhead racks where gravity and dynamic loads place constant tensile stress on the expansion joint, requiring rods to carry the weight and prevent separation.
Using control units effectively transforms the expansion joint into a self-restrained unit, protecting the system from catastrophic separation when ideal structural anchoring is impractical or impossible to install.
Re: Rubber Expansion Joins with & without Control Units
I would recommend getting in touch with OEM as well with specific case of expansion joint to better know the exact design basis.
That would just clear things out.
That would just clear things out.