Pressure acting on pipe wall
Pressure acting on pipe wall
(OP)
Hi all,
I am working on high pressure valve design and need help from piping experts..
when we pass a clean water at 390 bar (5656 psi) through pipe line, then what amount of pressure will act on wall of the pipe ?
as a beginner, i feel 390 bar pressure will not directly act on pipe as this pressure is converted into velocity to generate flow....also; i think this reduced pressure will act on internal parts of the valve....
I may be wrong but please comment on this..
thank you very much in advance
I am working on high pressure valve design and need help from piping experts..
when we pass a clean water at 390 bar (5656 psi) through pipe line, then what amount of pressure will act on wall of the pipe ?
as a beginner, i feel 390 bar pressure will not directly act on pipe as this pressure is converted into velocity to generate flow....also; i think this reduced pressure will act on internal parts of the valve....
I may be wrong but please comment on this..
thank you very much in advance





RE: Pressure acting on pipe wall
Valves tend to go in pressure rating steps and you need to assume that all the pressure acts on the inside of the valve.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Pressure acting on pipe wall
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"
RE: Pressure acting on pipe wall
RE: Pressure acting on pipe wall
390 bar ???........ you are a beginner ?????...... pressure not acting directly on the pipe ?????
Welcome to valve engineering in the third world and ......please, please stand far back !!!!
RE: Pressure acting on pipe wall
pressure acts on body uniformly is a universal law i don't want to challenge on that.
hope i made my self clear..
Thank again for your replies... :)
RE: Pressure acting on pipe wall
Independent events are seldomly independent.
RE: Pressure acting on pipe wall
And whenever your theoretical valve is closed rapidly in real a pipeline in the real world, the valve will see multiple pressure surges significantly ABOVE those simple static pressures just mentioned above of the theoretical no-flow design condition.
Recommendation: Design for the real world.
RE: Pressure acting on pipe wall
but when valve is open ...hydro-dynamic pressure will in to the picture i think that will act on internal of valve body ..it is a base rule in valve engineering ..that valve should be design at maximum pressure (actually 1.5 times the maximum pressure) but it will be more precise if we can find hydro-dynamic pressure...
come on guys its a real engineering world ...there is fact written somewhere ...There should not be any kind of force which is out of control while designing a component..
RE: Pressure acting on pipe wall
Pressure is not "converted" into velocity. Will the pressure in the pipe be lower further along - Maybe, maybe not. All depends on pipe size, flow rate, viscoisity, elevation, density, roughness of pipe etc etc. If the flow is low and the pipe vertical down, the pressure in the pipe might be higher if the static head increase is greater than the friction losses.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Pressure acting on pipe wall
but generally valve testing is done at static condition hence no dynamic forces are consider. however in real world due do tremendous velocity of fluid dynamic forces may cause damage to graphite seals, soft (PTFE) seats or abrasion in metal seats hence i am looking for hydro-dynamic pressure acting on valve components.
RE: Pressure acting on pipe wall
Independent events are seldomly independent.
RE: Pressure acting on pipe wall
Now what you're talking about is something completely different. In an ideal world, flow is controlled / governed / stopped and started using valves deisgned for the purpose, i.e. control valves. Isolation valves isolate static flow and open against low differential pressure.
However in the big bad world we actually live in valves are regualrly destroyed by being opened and closed under larege differential pressure or flowing conditions. Soft seats in these instances last for only a few operations and metal seats can be destroyed by hard particles as the velocity reaches huge numbers in the milli second before closure / as the valve opens. As far as i know this is virtually impossible to predict / calculate, but unless you are trying to make a valve that can do everything, then you need to rely on the data sheet which says that your valve is for isolation only....
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Pressure acting on pipe wall
Independent events are seldomly independent.
RE: Pressure acting on pipe wall
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Pressure acting on pipe wall
I'm so confused as to what he's really driving at in this post. Apparently so is everyone else. Let's hope you have a more experienced engineer reviewing your work, feng09!
RE: Pressure acting on pipe wall
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"
RE: Pressure acting on pipe wall
RE: Pressure acting on pipe wall
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"