Which one?

And was the phone shaking so much or had a dirty lens??

I can't tell anything from this picture but there is no code that will tell you this, only "workmanship" limits in the construction or installation specification, but then I guess you don't have one?

It might look shite, but if it works, who cares??

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Also: If you get a response it's polite to respond to it.

I am a fresh engineer working with few months experience only and seeking for guidance,
Thanks for your reply, posting new pic as well

Also why is this in the electric motors forum??

Mechanical or engine and fuel forums would be better.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

You are right, thanks

The engine manufacturer will issue an installation guide, it may be part of the O&M Manual. This will give a guide for installation of the exhaust flexible bellows.

So long as it is within the range of the bellows, that's what they are there for.

Exhaust systems expand and contract a lot and are often quite fragile so need some flexibility to avoid cracking due to vibration

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

I have seen many installations like this. They hold up fine provided you DO NOT have a flow liner. With this much misalignment the flow liner will rub on the bellows and wear through.

You can look at Metal Bellows supplier technical data, such as US Bellows https://usbellows.com/resources/types-of-deflectio....

In US Bellows installation instructions include this guidance

• Do not force-rotate one end of an expansion joint for alignment of bolt holes. Ordinary bellows are not capable of absorbing torque.
• Make the piping systems fit the expansion joint. By stretching, compressing, or offsetting the joint to fit the piping, the joint may be overstressed when the system is in service.
• It is good practice to leave one flange loose until the expansion joint has been fitted into position. Make necessary adjustment of loose flange before welding.

Misalignment will reduce the available inservice motion, and might reduce the service life, depending on the particulars of the specific bellows joint,


The expansion joint manufacturers association also publishes a guide publishes some standards and a practical guide.

Page 15 of the attached has a table of allowable offset, compression and stretch limits for flexible metal connections used in exhaust systems. CAT uses industry standard exhaust bellows materials and manufacturers and have found many other manufacturers have similar installation guidelines for their supplied exhaust flex connectors.

Hope that helps, MikeL

• https://files.engineering.com/getfile.aspx?folder=bb22d2fd-10d2-4de0-8c0f-4

The pipe fitters are pretty good at getting the alignment correct during installation. The joints come with shipping bars that hold everything true so the joint itself can be used for pipe alignment. I strongly suggest shimming with double the gasket thickness prior to welding it all up to facilitate removal and installation of the joint.

If this were a new assembly I was taking delivery of I would reject it. However, experience says it will likely last a very long time. So I wouldn't suggest shutting down to correct the joint. These installations don't operate anywhere near the rated pressure of the joint.

Depending on how the system is piped, you may find this mount of deflection once the system is hot. This is a result of poor design and not fit-up.

If this amount of deflection appeared over the operational life of the unit you may have some pipe hangers that need adjustment. I usually see exhaust systems hung from a threaded metal rod with rubber isolator. If the rod is too short the isolator will melt.

Hoxton123, TugboatEng, FacEngrPE, catserveng
Thank you so much for all information you provided, more success to you guys.