pipe roll

[S0606]

Hello,
I would like to get some information about pipe roll (rotation of the pipeline when installed subsea) and the ways to prevent it when installing tees or valves.

Regards,

 

[BigInch]

In what manner? What exactly are you doing?

http://virtualpipeline.spaces.msn.com

"What gets us into trouble is not what we don't know, its what we know for sure" - Mark Twain

 

[S0606]

Hello,

Actually I would like to know the ways used in industry to stop this happening.

Regards,

 

[BigInch]

Ya I'm sure, but there might be different ways to avoid it, depending on what you're doin' out there.

Are you towing out, lowering in... cutting into existing ?????

http://virtualpipeline.spaces.msn.com

"What gets us into trouble is not what we don't know, its what we know for sure" - Mark Twain

 

[S0606]

Hello,
Actually, I am interested in the ways of stopping it during deep S-lay installation.

Regards,

 

[BigInch]

What's going to roll it?

http://virtualpipeline.spaces.msn.com

"What gets us into trouble is not what we don't know, its what we know for sure" - Mark Twain

 

[S0606]

Well this is a phenomenon which happened as the pipeline tries to minimise the work done due to the reverse bending at the sag bend.This cases problems when installing valves and tees as it change the orientation

 

[BigInch]

Interesting. Is anybody trying to that now?

http://virtualpipeline.spaces.msn.com

"What gets us into trouble is not what we don't know, its what we know for sure" - Mark Twain

 

[S0606]

trying what?

 

[Yoman228]

Don't they just allow them to roll and then use special flange to connect them together?

 

[Sid7]

Thats why Swivels are used!!

Siddharth
These are my personal views/opinions and not of my employer's.

 

[BigInch]

Humm.... you both mean Swivel Flanges, I presume.

But those are for the connection, not trying to control it during laying. I think that's what S0606 is aftera. I don't know if anyone is trying to control it during laying, except by holding tension and not letting it overbend too much.

http://virtualpipeline.spaces.msn.com

"What gets us into trouble is not what we don't know, its what we know for sure" - Mark Twain

 

[Sid7]

"This cases problems when installing valves and tees as it change the orientation"

BigInch,
Yes meant Swivel flanges. I cant get what exactly S0606 is looking for!

Siddharth
These are my personal views/opinions and not of my employer's.

 

[BigInch]

Seems nobody get's it... so far.

I've always included a misalignment fitting "ball-socket type" in my tie-ins. It accepts a few degrees angular misalignment and rotates to any angle to match flange bolt holes, but that's for tie-ins, not during laying.

http://virtualpipeline.spaces.msn.com

"What gets us into trouble is not what we don't know, its what we know for sure" - Mark Twain

 

[S0606]

Thanks for you comment but what I am looking for is controlling during the laying process not at the tie-in. Actually, there are ways to do this such as attaching a bouncy tanks to valves to stop it roll and stay in the right direction.
I am looking for more information on the subject of rectifying this problem

 

[chief]

I have seen flotation sections attached to the upper section of the pipe as it is being runout, this keeps it orientated.

Offshore Engineering&Design

 

[Ussuri]

I am assuming he has appurtanences (sp?) on the pipe, such as inline tees, valves, plets etc which cause the pipe to become 'unbalanced' when laid.

 

[BigInch]

Isn't it easier to lay the pipes, then come back, and lower in and connect tie-in assemblies? We never did a layoff with a valve rolling down a stinger and that was in what I'm sure must have been much shallower water than is typical these days.

http://virtualpipeline.spaces.msn.com

"What gets us into trouble is not what we don't know, its what we know for sure" - Mark Twain