Joukowsky Head - Water hammer advise - formula use and surge mittigati
Joukowsky Head - Water hammer advise - formula use and surge mittigati
(OP)
Dear all,
I've Joukowsky Head method to estimate surge flow for a liquid line. This calculates 130% overpressure. Our internal standard only allows for 100% for lined and plastic pipes. We also plan to increase line capacity
1. Is this normal pratice.
2. What the experience with surge protections (on corrisive service ?) do NRV's work ? if so how effective etc.
3. Ive assumed 1500 m/s for the propagration speed eg water. but it is hydrochloric acid - do you know how to calculate this value ?
I've Joukowsky Head method to estimate surge flow for a liquid line. This calculates 130% overpressure. Our internal standard only allows for 100% for lined and plastic pipes. We also plan to increase line capacity
1. Is this normal pratice.
2. What the experience with surge protections (on corrisive service ?) do NRV's work ? if so how effective etc.
3. Ive assumed 1500 m/s for the propagration speed eg water. but it is hydrochloric acid - do you know how to calculate this value ?





RE: Joukowsky Head - Water hammer advise - formula use and surge mittigati
Increasing capacity will increase the velocity and worsen the transient pressures.
Usually speeds of sound are measured and bulk moduii calculated from that value, but it can be done backwards if you know the bulk modulus of HCL.
Some pressure balanced NVR's will work (especially for pump start and stops in small systems), but their helpfulness may be limited, if transient pressures high and sustained. In those cases a relief valve, surge relief valve, or surge tank, may be your best alternatives.
"I am sure it can be done. I've seen it on the internet." BigInch's favorite client.
http://www.youtube.com/watch?v=hpiIWMWWVco
"Being GREEN isn't easy." Kermit
http://virtualpipeline.spaces.live.com
RE: Joukowsky Head - Water hammer advise - formula use and surge mittigati
Fluid Transients in Pipeline Systems by ARD Thorley
Pressure tarsnients in Water Engineering Ellis.
In answer to you questions the Joukowsky equation does not provide the worst case in transient events if column separation occurs. Pressures have been experienced at 6-7 times the operating pressure.
NRVs in themselves do not solve waterhammer events however they need to be considered to avoid the problems. Refer www.noreva.de
Thereferences above will help you derive the celerity with HCL.
RE: Joukowsky Head - Water hammer advise - formula use and surge mittigati
Best regards
Morten
RE: Joukowsky Head - Water hammer advise - formula use and surge mittigati
"I am sure it can be done. I've seen it on the internet." BigInch's favorite client.
http://www.youtube.com/watch?v=hpiIWMWWVco
"Being GREEN isn't easy." Kermit
http://virtualpipeline.spaces.live.com
RE: Joukowsky Head - Water hammer advise - formula use and surge mittigati
http:
(I have found the paper with Google), you should correctly interpret the results or apply a more accurate methodology (keeping in account the complexity of your system)
RE: Joukowsky Head - Water hammer advise - formula use and surge mittigati
Best regards
Morten
RE: Joukowsky Head - Water hammer advise - formula use and surge mittigati
My apologies Morten.
"I am sure it can be done. I've seen it on the internet." BigInch's favorite client.
http://www.youtube.com/watch?v=hpiIWMWWVco
"Being GREEN isn't easy." Kermit
http://virtualpipeline.spaces.live.com