Question re: exhaust band clamps

[JPul]

Please forgive if this is a stupid question but...



I've seen a number of comments that band clamps are the preferred way to clamp exhaust system components together and I appreciate the ease with which exhaust systems can be taken apart when band clamps are used. But i don't understand how they can compress the outer pipe on a lap joint sufficient to achieve a sealed joint, given the width of the band. U-bolt clamps, given their very localized compression, certainly distort the outer pipe sufficient to achieve the seal.



Can someone please enlighten me.



Regards, john

 

[rscurtis]

They don't. The band clamp itself is the sealing element.

 

[WCPoe]

Please forgive if this is a stupid question but...

I've seen a number of comments that band clamps are the preferred way to clamp exhaust system components together and I appreciate the ease with which exhaust systems can be taken apart when band clamps are used. But i don't understand how they can compress the outer pipe on a lap joint sufficient to achieve a sealed joint, given the width of the band. U-bolt clamps, given their very localized compression, certainly distort the outer pipe sufficient to achieve the seal.

Can someone please enlighten me.

Regards, john

John,

They work great and they make both types, one for butt joints and one for lap joints. Even the butt joint style will stretch / deform enough to seal the lap joint when you tighten the heck out of them.

I believe several manufacturers carry them but I've had good luck with Walker 4. 00 inch band clamps I got at Summit:

Walker Exhaust 33280 - Walker Butt-Joint Band Clamps - Overview - SummitRacing.com (These are the butt joint style or smooth straight type)

or

Walker Exhaust 33224 - Walker Torctite Exhaust Clamps - Overview - SummitRacing.com (These are the lap joint style, - kind of hard to see the step in the clampin this photo)

Not too expensive and allow you to disassemble when needed as opposed the the traditional "u" style muffler clamps which deform, (crimp), the exhaust pipe making it difficult to separate.

Just my 2 cents.


Bill

 

[mwilson]

Also, grease or oil the flat surface of the band clamp before installing.



Very important because the clamp has to slide/stretch over the pipes as you tighten it. It makes all the difference in the world, trust me.



Mike.

 

[Bill Stockard]

Also, grease or oil the flat surface of the band clamp before installing.

Very important because the clamp has to slide/stretch over the pipes as you tighten it. It makes all the difference in the world, trust me.

Mike.

Yep, a "trick" we learned early when band clamps were first introduced on truck exhaust systems. A few drops of oil on the insude surface and spread it acrss the band with a finger is all that's needed for a very tight seal. The difference between a band and a u-bolt clamp: http://www.diesel-service-parts.com/exhaust-band-clamp.html

Bill

 

[DNDracing]

I used these on the MBRP 4" system I installed in June about 8,000 miles ago:

http://www.carquest.com/product_Exh...traight+tube__10151_-1_10651_89688_?acesApp=0

The clamp does the sealing. No leaks or issues. Second (or third I guess) the lubrication trick. I used a thin film of grease.

 

[JPul]

The light came on. Thanks guys.



Are the bands wide enough to cover the slits that some mufflers have at the inlet and outlet pipes, including the Donaldson that I recently installed.



2nd? Are the lap joint bands significantly preferred for lap joints?



Regards, John

 

[mwilson]

The light came on. Thanks guys.



Are the bands wide enough to cover the slits that some mufflers have at the inlet and outlet pipes, including the Donaldson that I recently installed.



2nd? Are the lap joint bands significantly preferred for lap joints?





Regards, John

(1) Yes, they will. Next time you are around big rigs with vertical mufflers have a look at the connections.



(2) Regular band clamps are fine for a lap joint if it is pipe to pipe. It's when using flex pipe to pipe that a step clamp is needed.









Northern Maine Mike.

 

[mwilson]

Well, it just dawned on me that I have a dooryard full of trucks so I took a few pictures for you.





Flex To Pipe Lap Joint

Another Flex To Pipe Lap Joint

Narrow Pipe To Pipe Lap Joint Clamp

Wide Pipe To Pipe Lap Joint Clamp

Mike.

 

[NavyDood]

I have had my HOG 4" exhaust installed on my truck in sig since Nov 05. It came with stainless band clamps which was one of the biggest selling points for me. I have flip flopped the muffler five times since the initial installation and never have had a single issue with the band clamps other than making my life and the job so much simpler. That even includes four winters living in Maryland and their overzealous ways of brining and salting the roads in the winter.

I literally just went out and snapped this photo.

#ad

 

[Prairie Dog]

Seems like the bands would be great if you think you may need to take the system apart once in a while too.

 

[JPul]

Thanks guys. This has been an education for me. Especially the pictures.



So am I seeing correctly that there is a slight distortion of the band on a lap joint pipe to pipe. I can clearly see the step in the band on the flex to pipe joint.



Regards, John

 

[NavyDood]

Thanks guys. This has been an education for me. Especially the pictures.

So am I seeing correctly that there is a slight distortion of the band on a lap joint pipe to pipe. I can clearly see the step in the band on the flex to pipe joint.

Regards, John

Yes, there is a step. Sorry, I didn't answer that in my first reply.

 

[JPul]

I reread all of the above information and I'm still not completely clear on stepped versus straight lap joint. The donaldson muffler on my truck has the 4" ID inlet/outlet with slots part way up the tube. Due to corrosion of the existing exhaust, I feel there is insufficient engagement between the exhaust pipes and the solid section of the muffler inlet/outlet for the U-bolt clamps that I'm using. So I believe that band clamps would provide this security.



So, in this case with the slotted outer muffler pipes, is the straight joint or lap joint preferred?



Thanks again for all your assistance.



Regards, John

 

[JPul]

Sorry, double post

 

[mwilson]

Sorry, double post

Double posts happen to me all of the time now, have gotten used to checking for it after every post.



Straight joint is what you want, that will be what is shown in the bottom photo of my post above. You really only use a step clamp when dealing with flex pipe to pipe.





http://www.donaldson.com/en/exhaust/support/datalibrary/061425.pdf



Mike.

 

[JPul]

Thanks Mike. That's what I'll order then.



Regards, John