Mettalic Bellows

The EJMA standards, suggest a minimum diameter of tie rods, but it is necessary to calculate the section of tie rods based on the load due to the internal pressure (traction bar) or based on the load due to the external pressure (buckling bar).

If you are particularly interested in the calcultion I can give you an idea in the way to do it in a pdf by e-mail

Pl. give that calculation (patelpk@yansab.sabic.com ) and still i am confuse about the tie rods are compelsory to have for each expansion bellow or with out tie rod also expansion bellow are possible .

Dear Sir I am also interested for it. because so many side I show all expansion joints tie rods has been buckled. therefor I had to face big problem. I hope you can solve it. Thanking you Amit Sharma

Dear Sir My E-Mail id is amityinstrumech@gmail.com

Obviously if the tie rods were buckling is because you have vacuum or external pressure.

As you now the first calculation is the load on the tie rods (Effective area of the bellows multiplied by pressure).

Choose the number of tie rods more appropriated to the calculated load and the obtained diameter of tie rods.

As you establish the length of the tie rods and depending on the slenderness you can use the more appropriate formula (Euler, Secant, Rankine,…) for both ends pin-jointed.

I hope this can help you but If you have any comments, let me know.

Best regards

tie rod is ot necessary with all the expansion joints, if tie rod bends , then it will be design failure or improper installation of expansion or anchor or slip guides because improper installation leads load transfer on tie rods, it may cause of bellow element failure and make a hazardous damage .if any one know more about metallic expansion joints then please add me at vijaybahadurhiflex3300@gmail.com

first of all i would like to clear about tie rod and limit rod

limit Rods. Devices, usually in the form of rods or bars, attached to the pipe expansion joint assembly whose primary function is to restrict the bellows movement range (axial, lateral and angular) during normal operation. They are designed to prevent over-extension or over-compression of the bellows while restraining the full pressure loading and dynamic forces generated by a main anchor failure.

Tie Rods. Devices, usually in the form of rods or bars, attached to the pipe expansion joint assembly whose primary function is to continuously restrain the full pressure thrust during normal operation while permitting only lateral deflection. Angular rotation can be accommodated only if two tie rods are used and located 90 degrees opposed to the direction of rotation.

so it is clear that where these particular rods are used.

tie rod are used for their own specific purpose as i had described above so it is necessary where it is required.

tie rod is requirement of types of expansion joint and site condition, manufacturer only follow the design aspect as per client requirement of site condition.

if you have to know more about it then you may follow me at vijaybahadurhiflex3300@gmail.com

please mention your reference (ihs globalspec)