Pumps - Lost in Translation

Hello,

I'm a native spanish speaker living in Bogotá, Colombia, but my degree is in Electronic Engineering. I've got some friends from Mechanical, so I will let them know, they might be able to help you.

Some books have their own symbolic abbreaviations, if this is the case, anyone would need more information, e.g., graphics, the whole page, book's title, etc.

Best regards,

Oscar Blanco

I empathize with your issue of translating a technical publication between Spanish and English. It is not easy (try running it through standard computer translating software, then retranslate to the original language, to see what issues arise). I frequently have to translate English technical information to Spanish, and it is no easy task, especially since I am seriously challenged in Spanish.

A couple of general issues- what Spanish is the original written in? For example, here in Panama, I find it rather easy to read one of the daily newpapers, but others are totally incomprehensible to me (same problem as English- which English- American, British, Australian, etc.- there are significant differences that can create serious misunderstandings). Another question- who is the intended audience for the manual- systems designers, installers, or general public?

With regards to your specific questions:

1. To interpret NP, NC, ND, NM and H, one needs the context in which these are used. If the manual is well-done, there should be a table, either in the front matter or as an appendix, that gives a key to the parameters being referenced. If no table exists, somewhere within the document should be a definition of the symbols being used. Also, is the mathematics originally English-based, or are these possible abreviations for the Spanish terminology? If you can not find within the document an appropriate symbol table, the actual formula containing the referenced parameters would help in determining the meaning. Furthermore, especially in established technical areas, such as pump technology, there is generally no international standard regarding these symbols. Without a context, it is impossible to determine what they represent.

2. Friction losses relate to the flow in the pipes to and from the pump, and are not the same as head losses, although friction losses are a component of total head loss. Head generally refers to the elevation difference between the surface of the source fluid and the ultimate out of the pumped fluid. Restrictions such as turbines, which extract work from the fluid, in the output of pump discharge, are generally defined in terms of pressure drop, which can then be converted to equivalent head. Friction losses, also expressed in pressure drop, are converted to equivalent head, as well, to give one a number for Total Head against which the pump must work.

3. I am not sure "impusive force" and "propelling force" would necessarily be synonyms. "Impulsive" would tend to imply an intermitent force, such as a piston pump would provide. A "propelling" force could be either impulsive or continuous- it would be whatever force is used to move the fluid (gravity would be a good example of a continuous propelling force, as would a centrifugal pump).

4. I would venture to say that a "theoretical" diagram is one created from a mathematical simplification of a physical phenomenon, while a "real" diagram would most likely be derived from actual measurements of parameters in an operating system. Again, out of context, it is difficult to say for sure that this is the meaning ascribed by the original authors.

5. I am not sure what you mean by "air chamber". A diagram would be helpful, or a more complete description).

I would like to be more helpful than I feel I have been, but I would need much more information. If you contact me via private message, I would be willing to provide more detailed assistance.

Thank you very much for your help! We are pleased to give you some more information.

The original is written in Spanish from Spain, and English must be British.The audience for the manual will be engineering students from universities in the UK.

About questions 1 and 5:

1. For NP, NC, ND and NM we have a description of what they stand for in the spanish text. We trusted there was an international standar regarding the symbols and that we just were'nt capable to find it... We add the spanish descriptions, hope it helps:

NP: punto de llenado o de capacidad total.

NC: punto de contacto o de capacidad mínima

ND: punto de rebose

NM: punto de remanso

5. The author talks about "air chamber" as a method used in a piston or a diaphragm pump to reduce these fluctuations of flow rate. He describes it as a closed tank partially filled with compressed air, situated at the discharging point of the pump.

Thank you very much indeed!

Apparently, your NP, NC, ND and NM refer to levels of a fluid in some sort of resevoir. NP would be "upper limit", NC would be "lower limit", NM would be "overflow level"; I am not sure what the "eddy point" ("NM") would refer to, unless it would refer to the point in which a reservoir on the suction side of a system would begin drawing air, resulting in pump cavitation. There are no "standard" symbols of which I am aware for these terms, but you might use "UL" for "NP" (the point at which a float switch or other level switch changes state and shuts down the pump filling the reservoir), "LL" for "NC" (the point at which a float switch or other level switch changes state to either start a supply pump or shut down a pump taking it's suction from the reservoir), "OF" for "NM" (the point at which the fluid being introduced into the reservoir is discarded into some drain). I have no suggestions for "NM", without an example of how this is used in context. Once again, these are not standards, and I know of now standards in common use for these terms. You must be sure to clearly and prominently define any symbols you incorporate into your translation (something like the table in your post).

The "air chamber" would normally be referred to as an "expansion tank".

One additional caution- I use American English (which is my native tongue, and which is more common in Latin America than British English). Some of our British friends may take exception to the terminology I suggest, and to my spelling.

Let me know if I can be of further assistance.

Although you refer to Archimedes' screw, I get the impression that most of your questions refer to a hydraulic ram. In the hydraulic ram, a relatively large flow of water taken from a stream passes through a relatively large pipe at low slope, developing significant momentum. When the flow is suddenly stopped by a flapper valve, the momentum is quickly converted into impulse (impulse=change in momentum, or F*T=M*∆V). Since the time is very short, the force can be very large, leading to high pressure which can pump small amounts of water to significant height to fill a storage tank or reservoir. An air tank in the output will significantly smooth the flow of water to the reservoir, and reduce the noise and stress on the output pipes. These devices are quite noisy, with most of the noise generated by the flapper closing.

Like cwarner, my native language is American English, although I have been speaking (Chilean) Spanish at home for well over forty years. I agree with his translations, except for his typo of NM for both overflow and eddy point (overflow should be ND).

In a hydraulic ram, the NM might well refer to the point where the pressure in the air chamber is equal to the static pressure of the water in the pipe to the reservoir, so flow would stop.

We would like to thank you for your good answers!! Muchísimas gracias! :)

Should we use "EP" for eddy point ("punto de remanso" in spanish)?

Thanks again!