Slurry/Tailings Pipeline Design

[Porter]

Does anyone have a good reference for the analysis of Slurry or Tailings pipelines? Especially where you would have multiple piplines supported on sleepers or piperacks. This type of analysis is not the same as a conventional stress analysis, as it is not within a refinery, and many times some of the pipelines are supported only by the ground, and left to expand where they want. The systems in question use expansion (slip type) joints to account for expansion in the line. The use of these types of expansion joints increases the anchor loadings drastically due to the pressure thrust component (easily in the 300k lbf range)

I am also interested in facility piping for tailings lines.

 

[stanier]

ASME B31.11 Slurry Pipelines

 

[stanier]

Some of the books I use are:-

Design of Slurry Pipeline Systems BE Jacobs
Slurry Transport using Centrifugal Pumps Wilson, Addie, Clift
Slurry Transport Wasp
Non Newtonian Flow in the Process Industry CharbbRa & Richardson
Slurry Systems Handbook Balunaga

Suggest you look into the ductile iron pipe manauls as they have the same design requirements as they use rubber ring joints. DIPRA, ACIPICO and EBRA can be found on the net.

 

[Porter]

Thanks for the reply Stanier. The piping system is designed to ASME B31.11, which will give me the code requirments, I was looking more for the practical, or rules of thumb type references that provide backup to their methodologies. For example, when you have three pipelines on a single common anchor, can you design the systems with only one in upset conditions, and the other two at design or normal operating? Can you design the anchors to only a single times thrust load, or do you design to multiple times thrust loadings for each line? Do the references that you list have this type of guidance?

I have seen pipelines with teflon sliders on the supports? I see this as a total waste of money, but maybe there is an unwritten rule for some systems to do this?

Thanks

 

[stanier]

What you are looking for is a basic piping engineering advice. It has little to do with slurries. It applies to all pipelines.

The design has to take into account all conditions. Yes, if there are three pipleins imposing a load on a support you have to consider the total load.

The need for sliding suports will come from your stress analysis. Teflon pads reduce friction. Graphited steel shoes have been used successfully for many years. Again it comes down to the friction coefficient used in your pipe stress analysis. Many pipes are supported on rollers to allow free movement.

Suggest you check ASME B31.3 to give greater insights.

As for references I suggest:

Piping Design-Kellogg
Piping Design and Engineering -Grinnell
Piping Engineering-Tube Turns
Piping Handbook Mohinder Nayyar
Piping and Pipeline Design George Antaki
Process Piping - Becht
Piping Handbook- Sherwood
Pipeline Rules of Thumb- McGraw Hill

Also visit

http://www.pipingdesign.com.

You may choose to join their discussion forum.

 

[Porter]

Pipeline stress is much different than you would do for process piping. Typically you are looking at a few inches of movement in process systems, with an above ground pipeline, you can be looking at feet. Plus you need to account for the line "snaking" its way down the corridor, or else you will have anchor loads of hundreds of thousands of pounds force which may be ultra conservative. Conventional stress analysis (Caesar) uses beam elements that don't allow for minor buckling of piping that iun the real world alleviates much of the stress in the piping, and it also does not adequately calculate the difference between thrust loading on expansion joints versus frictional loads on anchors.

I guess the real question is "Are there any references out there for design of above ground pipelines with slip style expansion joints acting in parallel?"

Thanks,

Porter

 

[stanier]

A pipe stress package does in fact allow you to model pipelines. Like any software it is as only as a accurate as the way you model supports. Beam theory will still hold. Thermoplastic materials do have large movements in process piping and this has to be designed to accomodate it.

If you locate a node at mid span of a pipe element, model the support as vertical only, with some gap restraint if using a U clamp with clearance you will see the pipeline snake.Beam theory still holds.

A pipe stress analysis package allows you to input minor initial deflections.

Admittedly secondary stresses need some careful analysis. This can be done using FEA or manual calculations to determine local conditions.

Where your pipe movement is in the order of "feet" then generally pipe loops are designed to accomodate. The loops can have tandem expansion joints in the legs if necessary to accomodate large strains.

Slip style expansion joints as I gather from your description are not suitable for slurry applications as the solids will interfere with the slip action and cause premature failure of the seals.

I have designed many tailings lines in thermoplastic materials where the coefficient of thermal expansion can be 20 times that for steel. The lower modulus results in the forces at anchors being reduced but they are still high enough to push concrete blocks over.

The support loads in the hundreds of thousands of pounds can & do occur if the system is not correctly designed.