Thrust Block for 8" SS Buried Pipeline 2

[marchieV]

Hello,

I just want to ask if thrust block is needed for underground pipe (8" -Stainless Steel)? What are the criteria should I consider inorder to know if the pipeline is qualified for using thrust block? For all I know, I used only thrust block for FRP buried line.

Thank you in advance.

Sincerely,

marchie

 

[LittleInch]

In general no, welded steel pipelines do not require "thrust blocks". These are normally used for changes of direction of push fit type pipes ( Ductile Iron or GRE) where the end cap force can pull the joints apart.

Is this what you mean?

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

 

[BigInch]

Thrust blocks or anchor block?

 

[LittleInch]

BI, Of all people I thought you wouldn't want or need either of them.....

marchieV - my answer encompasses both issues.

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

 

[bimr]

Almost all the thrust comes from pressure, not fluid momentum. Momentum is only significant if the pressure is very low and the fluid velocity is extremely high. The highest thrust load happens during hydrostatic testing pressure when the water is stationary. For typical pressures and velocities, momentum thrust is a very small percentage of pressure thrust and can be ignored.

Any pipeline with restrained joints (welded pipe, etc.) does not need thrust blocks as the thrust is carried in the wall of the pipe.

 

[fel3]

You can look here for a good explanation of pipe thrust restraint:

http://www.dipra.org/ductile-iron-pipe-resources/technical-publications.

Under the subheading "Design" you want "Thrust Restraint Design for Ductile Iron Pipe". The same principles apply to other types of pipe.

I try to avoid using concrete thrust blocks. However, I have had clients who trust concrete blocks more than joint restraints in spite of my best efforts to persuade them otherwise. I even had one client who insisted on adding thrust blocks to my restrained joints.


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"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[marchieV]

LittleInch,

Yes that's what I mean. I already read an article and references regarding thrust block and mostly it is all about non-metallic pipe.

Sincerely,

marchie

 

[LittleInch]

It's not so much "non metallic" as "non welded" or "non mechanically joint restrained", i.e. push fit.

You get plenty of metallic pipes which push fit together and plenty of non metallic pipe which are a single length or which fuse or glue or screw together to provide the required strength to resist the end cap force at changes of direction or tees.

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

 

[BigInch]

Just asking if he was really talking about thrust blocks, or anchor blocks. Sometimes different languages don't translate very precisely.

 

[lilliput1]

You do have to anchor the piping within 5 ft of where it exits the building wall so that pipe movement due to thermal expansion/contraction would be limited so water seal at the pipe wall penetration can be maintained. The anchor can be within the building or in the ground. Thermal expansion/contraction in the underground piping need to be addressed either by enclosing the piping within conduit and providing bends and clearances within the conduit to accommodate pipe movement or if expansion/contraction is small, use bends and flexibility of piping to not overstress piping.

 

[marchieV]

BigInch,

Sorry for delayed answer. Yes, my concern is about thrust block.

Sincerely,

marchie