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Hi there, hope everything is fine and wish you a great year. Please, I am writing you for following issue. In the past a copper pipe, having a certain diameter, let's call it D, and thickness, t, has been tested in a fatigue vibrational test. The pipe was fixed at the ends to a metal sheet...

Hi there ! hope everything is fine ! Please, I am contacting you for following issue. In the past I have utilized a pipe of copper having diameter D and thickness t. It has been under a vibrational fatigue test and has passed the test. I have then changed the pipe. The new one has got a...

Hi I think that still one equation is missing since there are three unknowns Unknown: 1 - t cold outlet 2 - t hot outlet 3 - capacity available equations 1 - Q = m*c*(tin-tout) (for water) 2 - Q = UA*LMTD It seems one equation is missing since it can't be utilized the one similar to 1...

HI there, I have made a research in old posts, unfortunately not finding the specific answer I’d need. Following thread is quite interesting, nonetheless is not giving the complete answers thread403-138316 My question refer to Ammonia and liquid overfeed cycles. 1 – which are the reasons why...

Hi there, Today I am posting a double. I red this interesting post, thread378-227715, where I could find an exhaustive information concerning possible formulas for friction factors. I'd have following questions: each of these formulas are affected indirectly by temperature. Temperature...

Hi there, hope somebody can help me I have a 180 bend and I'd like to find the value that allows me to find the equivalent length, that is (L/D)eq = ? I am looking for values for pipes having various radius. when looking in previous posts, I found thread378-8478. Nonetheless, I'd like to...

Dear all, Hope somebody can help me to clairfy this topic. I have seen some threads about this topic, but none of them is answering my next question. I have measured the air flow, rpm and absorbed power of a three phase axial fan at two different fan speed – delta and star connection. I will...

Hello, first of all I'd like to thank you for all the kind answers to present mail. Concerning your questions: to Mr gtaw - we are speaking about a butt brazing to Mr Duwe6 I agree with what you write. An hypothetical argumentation can be: may the less content of Ag help the wetting ability of...

Hello, many thanks. It is a first step ahead, but if you see there are some restrictions. As you can see, the coils row number is always limited to 8. In this case one degree of freedom in the system is eliminated. Many thanks

Hello there, I'd need some help for following issue. I'd like to find a method for run around coil calculation. When looking to past threads, I found some references to ASHRAE (thread403-249667). I tried to consult them but they weren't exhaustive. Neither google gave me detailed pieces of...

Apologizes, I almost forgot. Operating fluid would be water or fluids with glycol. Temperature won't exceed 300F.

Hello, many thanks for your answer. the topics are: current brazing Ag25 new brazing Ag15 material Copper C12200 many thanks for your help

Hi there, I am facing to the input of lowering the Ag content in brazing alloys for big diameter copper tubes in order to save money. I decided to realize some burst tests on two different tubes (diameter of 3ft, three of them brazed with low Ag content and three brazed with standard alloy)...

Hello there, I have been recently informed about an open source code, called salome, to realize fem structural analysis. Has anybody of you ever heard about this code ? Which are the differences with respect to traditional –and not free- codes ? Why should one change from a standardized...

Many thanks to everybody Wish you a wonderful 2011

Hello, apologizes for not being exhaustive. I’ll try to be more clear. I am dimensioning an heat exchanger, not a system neither a refrigerator. Considering the dimensions and pressure related, this heat exchanger can be classified as a pipe. For this reason I am referring to ASME B31 In...

Hello, sorry for delay ! Many thanks to your help, Waterpipe, you sent me a link that has clarified my doubts. Thanks a lot Mr Davefitz, let's consider one issue solved :-) To both: Merry Christmas and to the next time !

Hello, many thanks to everybody. Mr Snorgy, indeed I was looking for a correlation for calculating heat transfer coefficient your rule is extremely helpful. Please, which is the unit of temperature ? C ? K ? Many thanks

Hi there, hope somebody could help me or share his experience. I am dealing with a B31.5 analysis of an heat exchanger, that may be classified as a piping. What puzzles me is following issue. If I utilize the straight tube formula as indicated in the standard, I get a burst pressure much lower...

Hello Hope somebody could give me an good piece of advice. Following is the topic. I have to design an heat exchanger to cool oil temperature. My problem is choosing which correlation utilizing for calculating pressure drop and convective heat transfer coefficient. Because of large viscosity...