WATER HAMMER IN CHANGE OF MATERIAL
WATER HAMMER IN CHANGE OF MATERIAL
(OP)
Hello everybody
I have been designing a irrigation system, i shall install steel pipe for 20 first meters and the rest, 12 km, in GRP, so my doubt is: what happen in transition GRP-STEEL during a water hammer phenomen?
What's background for the majority of softwares for hydraulic transient analysis for this case?
The results seems no be real, because in the change of material the overhead up to 10 time the pressure, while in GRP is around 20%.
I'm not sure if i should use the concept: equivalent celerity.
I hope you can help me
Thanks in advance
César
I have been designing a irrigation system, i shall install steel pipe for 20 first meters and the rest, 12 km, in GRP, so my doubt is: what happen in transition GRP-STEEL during a water hammer phenomen?
What's background for the majority of softwares for hydraulic transient analysis for this case?
The results seems no be real, because in the change of material the overhead up to 10 time the pressure, while in GRP is around 20%.
I'm not sure if i should use the concept: equivalent celerity.
I hope you can help me
Thanks in advance
César





RE: WATER HAMMER IN CHANGE OF MATERIAL
Have you established how water hammer will occur?
It is best to design out or put in operation procedures to prevent occurence, though you cannot rely on people to follow procedures.
Regards Brian
RE: WATER HAMMER IN CHANGE OF MATERIAL
Best rgards
Morten
RE: WATER HAMMER IN CHANGE OF MATERIAL
Can you prevent the watterhammer event ?
Installing "venting valves" at a high point...just downstream of the pumps wopuld help ???
-MJC
RE: WATER HAMMER IN CHANGE OF MATERIAL
Thanks so much for your answers, i agree with your answers, but i want to know what happen with the overpressure behavior in this transition change material?, according with jokosky theory the change is very strong.....i mean in steel pipe the over pressure is around 100 psi and for GRP pipe si around 20, i bet that the radical change is not real.
Also i want to know, is anyone have ever ear about equivalent wave speed?
a=L1+l2`+....Ln / (L1/a1+L2/a2....Lnan)
where
L= pipe lenght
a=wave speed
I asked for that because in the pipeline that we have been analized i have around 13 km of grp pipe and 20 m for steel pipe, so for the transient analisys, it's important know the wave speed. may the wave speed is less. we have been used Hammer XM as software
If i use this equivalent wave speed the over pressure is reduced...
I hope you can understand me and help me
Thanks sou much
César
RE: WATER HAMMER IN CHANGE OF MATERIAL
On a slightly different note is your question really "what is the optimum transition design from steel to GRP?"
Regards Brian
RE: WATER HAMMER IN CHANGE OF MATERIAL
RE: WATER HAMMER IN CHANGE OF MATERIAL
I have seen damage that can be done on systems with much smaller volumes but with higher speeds and this was largely atributed to extremely quick shutting times of valves.
RE: WATER HAMMER IN CHANGE OF MATERIAL
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"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/