So at the end of the day we have 73 m section with air at @ 7,16 bar and 457 m section with water column at 45,7 bar.
It is important to know air pressure at the top when the pipe is about to be vented.
Yes, but, my calculation was for air when the pipe was laid down. So if we have for example 106 m3 volume of air in pipe (same as pipe inner volume). When the water rushes in at 53 barG (we assume non of the air escaped) air will be compressed to volume of:
1 bar x 106 m3 = 53 bar x V2 ====>...
I used p1V1 = p2V2 to calculate the volume of the compressed air when the pipe is laid at the bottom.
But when the pipe is turned vertical we need to take into account the height of the water column in the pipe. At what pressure there will be equilibrium between water level and air inside and...
Hello all,
I need Your help with one real / theoretical situation.
We have submerged pipe filled with air at atmospheric pressure that is closed on both ends.
The hole is formed on one pipeline end and the water starts flooding the pipe.
Let's assume pipe is tilted somewhat and that no air...
It was probably due to my error during calculation.
I understand what are You trying to say. Pressure is monitored from both sides of the pipeline, via instrumentation on pipeline heads. So operator will know when the pressure wave reaches the other side, also this slow rate of depressurization...
As I told gmax137 data from the first post is somewhat fictional. I'm using this 900 km, 42 inch pipeline as a benchmark since I know they used 32 mm orifice for depressurization.
I meant to edit that post and forgot, I apologize... Using those two equations i provided in post 5# I got the same result as was given to me by a third party. Firstly, I calculated the change in pressure caused by release of volume of seawater in the pipeline ΔV/Δp from second equation, and got...
Thank You for offering help with additional calculations, but since we are working with really slow depressurization rates and flow speeds this estimate should suffice. If you have an itch and want to resolve it with infinite pipeline calculations, I will be glad to try and resolve it together...
Discharge manifold contains pipes with orifice plate flange and two valves specifically designed for each pipeline, so once the pressure is released, head together with manifold is removed so longevity is not an issue. One would even argue that theoretical fast wear would expand the orifice...
I'm beginning to understand what was the issue.
Let's say we know how much cubic meters of seawater was necessary to fill the pipeline completely.
Now we start to pressurize the pipeline until desired pressure px is reached, and we know that we had to pump additional Vx cubic meters of seawater...
I started with the following expressions:
Pipe expansion is taken into consideration with above expression.
Volumetric expansion of liquid due to reduction in pressure is calculated with the following expression: V1 = V0 (1 - (p1 - p0) / E), but I have trouble incorporating it with...
Since it is not a issue right now and I'm preparing for when it might arise I have no detailed diagram to send.
It should look like example (very crude) below:
Pipeline has a diameter of D, heads can have a diameter equal or greater than D. Heads are considerably shorter than pipeline, for...
Dear all,
I have a headache and I need you help, with the following problem.
I need to create excel sheet for the calculation (estimate) of the size of the orifice on the orifice plate that will produce a pressure reduction rate in pipeline at 0,5 bar per minute. It is not important to...