cooling water underground piping system
cooling water underground piping system
(OP)
Dear friends
Construction company, has designed all the CWS and CWR as an underground system.
It is a high flow system with CWS in 60" and CWR in 68" and flow, about 30,000 cubic meters per hour.
None pipe supports has been considered . The above ground CWS pumps laid on a concrete slab, connect to a floating underground system. The same happens for any other equipment placed around the plant, where the UnderGround pipe systems connects to AboveGround, like pipe racks, heat exchangers ,vessels,power plant condenser etc.
I have already told the vendor to do stress analysis, considering the flow dynamics in elbows, branches, and the relative displacement due to soil resistance variation because of the ground water levels, along the weather seasons, with weight and dynamic loads acting .
On concrete blocks or any other support, but the soil friction (lime type and clay).
The only standard I have read about, is B31.8 .Does AWWA has some information.
I will appreciate your opinion
Regards
Luis
Construction company, has designed all the CWS and CWR as an underground system.
It is a high flow system with CWS in 60" and CWR in 68" and flow, about 30,000 cubic meters per hour.
None pipe supports has been considered . The above ground CWS pumps laid on a concrete slab, connect to a floating underground system. The same happens for any other equipment placed around the plant, where the UnderGround pipe systems connects to AboveGround, like pipe racks, heat exchangers ,vessels,power plant condenser etc.
I have already told the vendor to do stress analysis, considering the flow dynamics in elbows, branches, and the relative displacement due to soil resistance variation because of the ground water levels, along the weather seasons, with weight and dynamic loads acting .
On concrete blocks or any other support, but the soil friction (lime type and clay).
The only standard I have read about, is B31.8 .Does AWWA has some information.
I will appreciate your opinion
Regards
Luis





RE: cooling water underground piping system
Are these steel pipes?
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: cooling water underground piping system
The design code is B31.3 but there is no underground piping on this code
Does code 31.1 has it?.
I am quite sure that another's companies have considered the supporting for this service.
RE: cooling water underground piping system
RE: cooling water underground piping system
B31.8 is similar, but reserved for gases.
Chilled water is not power piping B31.1, nor is there any process, so process piping B31.3 is not applicable.
I would have thought you want B31.5 and other ASHRE standards, see here
http://www.baltimoreaircoil.com/english/resource-l...
you must get smarter than the software you're using.
RE: cooling water underground piping system
RE: cooling water underground piping system
Is not easy to find an standard that follow this type of this underground design.Forces induced by elbow reduction and branches, added to the type of soil and ground water.
May some stress analysis considerring thos forces can help to solve this. This is floating underground system conneectin to fixed system above ground
Regards
Luis
RE: cooling water underground piping system
you must get smarter than the software you're using.
RE: cooling water underground piping system
RE: cooling water underground piping system
RE: cooling water underground piping system
http://www.steeltank.com/Portals/0/pubs/Welded%20S...
RE: cooling water underground piping system
Any set of steel pipes full of water will not "float". If you have waterlogged ground you might have an uplift force, but use soil, concrete or anchors to keep it down in the occasional circumstances when the pipe is empty.
If the ground swells or contracts a lot compared to the above ground slab then the design will need to allow for this and be quite flexible.
If the vendor does stress analysis then you need to ask him what code he is analysing this to.
Not many details here so not many detailed answers..
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: cooling water underground piping system
All the pipes has been buried without any consideration about, ground water, settling of the pipe after loading it, no concrete blocks or no support blocks on the discharge cooling water pumps manifold. I am very sure that this system will move, that is the reason the why I was saying a floating system. Because above ground, is almost fixed on concrete slabs or in pipe racks.
Regards
Luis
RE: cooling water underground piping system
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: cooling water underground piping system
RE: cooling water underground piping system
While there is probably precedent for some fully rigid pipeline systems basically working with at least quite sturdy soils and with the strength and some perhaps non-obvious flexibility in steel piping, if there is relative movement expected beyond these capabilities I guess it might be possible to insert a couple flexible, e.g. bolted couplings (i.e. "rocker pipes") in the transition areas it sounds like you are apparently worried about to provide for some movement. If so, you must still provide any restraint where needed, e.g. for any thrust foci influencing the piping, in the areas, as needed.
RE: cooling water underground piping system
you must get smarter than the software you're using.
RE: cooling water underground piping system
you must get smarter than the software you're using.
RE: cooling water underground piping system
How the bleedin' d*mn h*ll do "engineers" get away with this kind of cr*p? What are people being taught overseas?
RE: cooling water underground piping system
you must get smarter than the software you're using.
RE: cooling water underground piping system
That is correct; the place has tropical weather, very rainy in summer, like today, 60mm in 6 hours. The engineering company said they are studying the problem. So there is no freezing condition.By inspection I should, say that the discharge manifold of the cooling water supply should have been underground supported, (30.000 cubic meters per hour flow).The same problem we have with the pipes going to big condensers and connecting the pipe rack and also with big diameter (68”) cw return pipes , back to the cooling tower. I saw the information at ASNSI B31.1,good to read it.