Design of Nonwelding Leak sealing Devices 1

[Lebpower]

Anyone with experience in the design of Leak sealing Devices, specifically Bolted clamps.

Bolted clamps
1.-) I want to know the standard that provies me the formulas to calculate the thickness of the body of this device, the bolt sizes and the minimum thickness of the bolted zone

- There are any service/pressure limitations (based on standards) on the use of these devices?

- How to calculate the minimum axial thrust loads and The effect of enclosing(crushing) forces on the pipe?


Thanks in advance.

R.A.

 

[GD2]

Lebpower,
There is no cookie cut equation to design a split sleeve repair clamp. It needs both a pressure design and structural design for a clamp. The manual calculation can be very complex. The best place to order a clamp could be the companies like Furmanite, hydratight etc who can design the appropriate clamp for you. In places where you don't have an inhouse engineering standard in place, it is considered a catalogue item from Third Party.

Ganga D. Deka, P. Eng
Canada

 

[A8yssUK]

Honestly, long term view, repair/replace the broken leaky section. It will only come back to haunt you otherwise.

Stopping the leak doesn't necessarily, stop the cause of the leak..

 

[LittleInch]

A pity lebpower hasn't bothered responding further, but in practice you can't use a metal to metal clamp like that to seal a leak. You don't have enough sealing force.

There are a couple of clamps which include a jack screw to force it's way into a small pin hole leak, but otherwise you need sealing rubbers.

Like this

http://www.luse.com/split-sleeve-pds/

http://www.plidco.com/product-line/split-sleeve

Plidco make a lot of leak sealing sleeves as do TDW.

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

 

[thecrazymoon]

Hello all...

I'm new to this forum... so if I violate any rules, please call me out...

I am not aware of what formulas Furmanite, the forefather of on-line leak sealing, use to calculate all their leak sealing clamp components. Maybe they are doing FEA.

In my experience, I have encountered leak sealing clamp design calculations using ASME BPVC. Vessel shell thickness to decide the clamp shell thickness, formula for Flat Unstayed Heads to decide the endplate thickness (the head of the clamp where the bore shall be the leaking pipe's actual outside diameter), Flange Formula to decide the thickness of the lugs (the plates where the bolt shall be arranged to hold both sides), and Flange Bolt Root Area Calculation (to decide the size of bolts).

Are these formulas applicable for designing these "pressure vessels"?

Appreciate all the help!

P.S.
These leak sealing clamps, designed using the above formulas, have all been successful in arresting the leak. Steam leaks above 100kgs/cm2g design pressure and temperatures above 500°C.

 

[LittleInch]

the crazy moon.

You should really start your own post and not "hijack" someone elses one. You can refer to another post be starting " in this post .... it says xyz. How about abc?"

But yes I think furmanite use BPV designs for the shells and some FEA design for their custom made devices. They tend to make bolted half shells which then seal on the pipe OD.

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

 

[Ehzin]

Crazymoon, I don't recall the particular leak sealing/clamp vendor but Roark's is also used. It's referenced for endplates similar to what you mentioned due to specific geometries that aren't specifically covered in ASME codes. There's another major reference although I don't recall its name. I may be able to check next week.

Although I agree on starting a new post to get responses tailored to your question. If Lebpower returns then I'm sure he can get more feedback.

Thanks,
Ehzin

 

[thecrazymoon]

Dears LittleInch and Ehzin,

Greetings.

Thank you for your replies and I'm sorry if I did "hijack" leb's post. Just wanted to try to make him "engage" in the thread once again. Thank you again kind sirs...

All the best!

 

[blakmax]

Some guidance in ISO 24817 para 7.5.13.3 Clamps and other repair systems Maybe that helps.

Regards

Blakmax