1000m Vertical Pipeline
1000m Vertical Pipeline
(OP)
A project on the drawing board features a mine dewatering facility. The pumps at the base of the mine will pump vertically up to the surface into a tank.
It is proposed to use victaulic couplings of the high pressure variety. Supports will be rockbolted into the wall.
Please comment on the following rationalization.
There is a concern that the tolerance in the groove of the coupling will allow the pressure thrust to be transferred to the supports. These forces should be balanced either side of the support apart from the mass of the pipe & water. It would only be a problem if there was a pipe burst and the unbalanced forces would shear the support.
Thermal strain is yet to be determined as the mine temperature is to be assessed.
Have you any direct examples of this type of installation?
It is proposed to use victaulic couplings of the high pressure variety. Supports will be rockbolted into the wall.
Please comment on the following rationalization.
There is a concern that the tolerance in the groove of the coupling will allow the pressure thrust to be transferred to the supports. These forces should be balanced either side of the support apart from the mass of the pipe & water. It would only be a problem if there was a pipe burst and the unbalanced forces would shear the support.
Thermal strain is yet to be determined as the mine temperature is to be assessed.
Have you any direct examples of this type of installation?





RE: 1000m Vertical Pipeline
David
RE: 1000m Vertical Pipeline
RE: 1000m Vertical Pipeline
Couple the pump discharge to the pipe with a flex hose to isolate vibration and pipe movement.
RE: 1000m Vertical Pipeline
Unfortunately the customer has procured the pipe and couplings. My role is to certify what is an inadequate design.
The use of oil & gas techniques may have problems with code compliance as the nominated code is a process piping code.
From the safety aspect the pipe is in the mine shaft and thus needs to be considered differently to an oil well. The latter are installed in a bore . If they fail they do not present the same safety issues. I have already canvassed the idea of a separately drilled bore to the pump station to avoid safety issues.
RE: 1000m Vertical Pipeline
RE: 1000m Vertical Pipeline
**********************
"Being GREEN isn't easy" ..Kermit
http://www.youtube.com/watch?v=hpiIWMWWVco
http://virtualpipeline.spaces.live.com/
RE: 1000m Vertical Pipeline
If you just must, then you could run a large diameter conduit (maybe spoolable composite pipe?) and drop your pump and tubing inside of it. This is a really easy application if you don't lock yourself into dumb.
As to "nominated code", a person nominated it, that choice was not divinely ordained. If you are locking yourself into sub-optimal choices because of that then you have a truly sad operation.
David
RE: 1000m Vertical Pipeline
**********************
"Being GREEN isn't easy" ..Kermit
http://www.youtube.com/watch?v=hpiIWMWWVco
http://virtualpipeline.spaces.live.com/
RE: 1000m Vertical Pipeline
RE: 1000m Vertical Pipeline
1) There are 2 types of high pressure couplings, flexible and rigid. You need to specify which type is being used.
2) Flexible type groove connections will behave exactly like a tied bellows joint, the pressuse thrust developed is calculated from the pipe OD, the expansion and contraction is based on the movement limits of the victaulic coupling in question. Judging from you discription you will start at the bottom of the mine and assemble the pipe as you go up. This means you will have compressed gaps all the way up your run. For flexible couplings I would have a vertical ancor at the base (near the pump) and allow all the thremal and pressure growth to move up. I would then deal with all the expansions at the surface with either flexibilty or an expansion joint. This makes maintenece easy.
3) If the victaulic coupling are the rigid type, you can treat the expansions the same way you would treat welded pipe. You only need to evaluate thermal growths.
4) Remember to check that they have enough wall thickness in the pipe. By code (B31.1, B31.3, B31.9) the groove depth must be subtracted from the pipe available wall thickness (nominal thickness minus 12.5% under thickness tolerance, corrsion allowance, and mechanical strength). The reduced value must then be compared to your minimum wall thickness required.
Just my two cents worth
A question properly stated is a problem half solved.
Always remember, free advice is worth exactly what you pay for it!
http://www.ap-dynamics.ab.ca/
RE: 1000m Vertical Pipeline
Looking in detail at the high pressure vic coupling style 808
http://www.victaulic.com/Docs/lit/15.01.pdf
They are the flexible type, you will have growths all the way up the shaft. I would let it grow and deal with it up top, where its easy to handle.
A question properly stated is a problem half solved.
Always remember, free advice is worth exactly what you pay for it!
http://www.ap-dynamics.ab.ca/
RE: 1000m Vertical Pipeline
RE: 1000m Vertical Pipeline
My apologies, I misunderstood your post.
A question properly stated is a problem half solved.
Always remember, free advice is worth exactly what you pay for it!
http://www.ap-dynamics.ab.ca/
RE: 1000m Vertical Pipeline
ColonelSanders83: No problem. Accepted. Perhaps my post wasn't clear enough.
RE: 1000m Vertical Pipeline
The thoughts expressed by ColonelSanders83 are exactly as I was thinking.
Perhaps i did not make myself clear. I am not the designer. I have come in down the track on this job just before they start installing and they want a certification of an incomplete design. Trying to "make a silk purse out of a sow's ear".
The pipes are 5m in length. hence if there is 1mm tolerance in the couping groove the pipe could move 1m! There is something like 200t of piping here so not all the couplings are going to move to their extremety with pressure applied. I would then be concerned about column buckling at the base of the pipe.
BigInch you are right the question is about the couplings.
I would not be looking at using flexible hoses at this pressure.
Pipe is 10" so dont know if API5L tubing is the way to go.
Code has been already specified by whom do not know and I do not know if this is a company standard. i shall of course be asking.
Changing codes to make a design work is a bit like reducing safety factors to allow an aircraft design to proceed. It does not reduce risk.
RE: 1000m Vertical Pipeline
Micalbrch called it correctly in suggesting that mining engineers are the go to guys for this type of exercise, and I have posted a response over there for any and all interested parties... of course being refeerred to as dwarf does not endear Mical to me but Ill get over it!!!!!!!
If the customer has already purchased sched 80 10 inch pipe then the customer better be prepared to spend some time in the shaft with the miners showing them how to bolt this material directly to the rock and still keep the pipe more or less vertical. I know exactly how to do it if the pipes are installed on the shaft steel but unless there is a major change in the design philosophy, this is a gong show in the making.
And I have used oil field technology once or twice in my career, but with all due respect to oil field engineers , I cannot for the life of me think what advantages oil field pumps might have over standard off the shelf mining submersible pumps.
Incidentally 10-12 diameter discharge lines sound about right, and this should give non mining personnel what flow rates and electrical horsepower can be anticipated during this project.
RE: 1000m Vertical Pipeline
RE: 1000m Vertical Pipeline
RE: 1000m Vertical Pipeline
RE: 1000m Vertical Pipeline
Now lets assume that the OP's mine is/was smaller at say 1000 tons per day and was only in production for say 7 years, this is still going to be an expensive exercise, and it doesnt matter if we are talking Australian , Canadian or US dollars.
If there was ever an instance of a client / owner needing competant professional advice,rather than trying to save a few thousand dollars up front, surely this one would have to be at the top of the list.
RE: 1000m Vertical Pipeline
**********************
"Being GREEN isn't easy" ..Kermit
http://www.youtube.com/watch?v=hpiIWMWWVco
http://virtualpipeline.spaces.live.com/
RE: 1000m Vertical Pipeline
The design was done by the mine engineers who I gather have done it before. However there has been a change in staff. I have yet to see any documentation and so cannot give accurate information.
Your point about the tolerances in the shaft in terms of available space are very relevant. Safety cannot be compromised in my opinion.
You did not comment on the Victaulic couplings and any previous expereince of their use? In my opinion ductile iron components in high pressure applications do not have a place unless they have been verified as to strength using something like upper bound limit state strain analysis (FEA) and preferably testing.
The experience of rock bolting to the shaft comes from the mine engineers.
Rest assured I will withdraw from the project if it gets hairy when I see the documentation.