Techniques for measuring pipeline surge/shock/hammer?
Techniques for measuring pipeline surge/shock/hammer?
(OP)
If someone is aware of any techniques used to analyze and measure pipeline shock / surge and guidelines for them, would you please pass them along to me?
The pipeline in question is a 5 mile long force main sewer line (peak pressure 120 psig). The discharge is open ended. The concern is that the line and pumps were designed for much higher sewer flow rates than currently exist. This has caused an issue with pumps cycling on and off as the minimum pump flow is greater than the average sewer flow. There is a surge tank at the suction side of the pumps but they do cycle on /off dozens of times/day. The concern is the sudden shock/surge the pipeline may be experiencing as the pumps start and overcome the checkvalves near them.
I've logged pressure readings during these times and I've only noticed a fluctuation of a few psi during cycling. The calculated pressure drop during full flow is 0.5 psi.
I've read that in order to see a pipeline "shock" or "surge" the instrument must we respond very fast and mine don't (1 second interval).
My gut feel is that this isn't a problem but if it is it would be much cheaper to replace the pumps than broken pipeline segments/vacuum breakers/air reliefs. It would still be upwards of $50K to replace the pumps though, rather not if there isn't any benefit.
Your advice would be greatly appreciated! Thanks!
The pipeline in question is a 5 mile long force main sewer line (peak pressure 120 psig). The discharge is open ended. The concern is that the line and pumps were designed for much higher sewer flow rates than currently exist. This has caused an issue with pumps cycling on and off as the minimum pump flow is greater than the average sewer flow. There is a surge tank at the suction side of the pumps but they do cycle on /off dozens of times/day. The concern is the sudden shock/surge the pipeline may be experiencing as the pumps start and overcome the checkvalves near them.
I've logged pressure readings during these times and I've only noticed a fluctuation of a few psi during cycling. The calculated pressure drop during full flow is 0.5 psi.
I've read that in order to see a pipeline "shock" or "surge" the instrument must we respond very fast and mine don't (1 second interval).
My gut feel is that this isn't a problem but if it is it would be much cheaper to replace the pumps than broken pipeline segments/vacuum breakers/air reliefs. It would still be upwards of $50K to replace the pumps though, rather not if there isn't any benefit.
Your advice would be greatly appreciated! Thanks!





RE: Techniques for measuring pipeline surge/shock/hammer?
"I came, I saw, I made it better."
-Ode to Industrial Engineers
Will ChevronTexaco Corp.
RE: Techniques for measuring pipeline surge/shock/hammer?
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RE: Techniques for measuring pipeline surge/shock/hammer?
RE: Techniques for measuring pipeline surge/shock/hammer?
Any pressure waves, shaking, things happening when you trip the pumps off?
What's the pump horsepower rating, the pipe diameter, pipe material, and flowrate/velocity now and at maximum design flowrate?
There are hydraulic analysis programs that can analyze these things for potential problems. Let me know if you have more interest.
**********************
"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/
RE: Techniques for measuring pipeline surge/shock/hammer?
RE: Techniques for measuring pipeline surge/shock/hammer?
The pipe is 25" sched 20 ductile iron. No shaking or
otherwise violent/noticeable symptons after startup/shutdown.
RE: Techniques for measuring pipeline surge/shock/hammer?
"I came, I saw, I made it better."
-Ode to Industrial Engineers
Will ChevronTexaco Corp.
RE: Techniques for measuring pipeline surge/shock/hammer?
RE: Techniques for measuring pipeline surge/shock/hammer?
The original company that did the design did a surge analysis and it may still be fine. This company's resources/reputation have gone down a fair bit in the nearly ten years since the design was completed.
I'd like the defacto, industry expert, goto person/company for this kind of thing to have a look. Do they exist? I think high pressure sewer lines are a bit of a rarity but I imagine this kind of installation exists in the petroleum industry with much higher design requirements....can't have vacuum breakers/air reliefs spewing oil everytime there is a problem.
RE: Techniques for measuring pipeline surge/shock/hammer?
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Techniques for measuring pipeline surge/shock/hammer?