Seems to me this article was little about valves and much about engineers. Engineers have to be able to take the heat and pressure. There are different types and sizes for different applications. It's important to choose the right one. Quality is important.
I think this article is part of a program to develop bullets for a post-entry-level resume.
Note the bio info: "worked for ... for more than five years and takes pride in sharing his rich experiences in this field..."
I don't discredit anyone's 5 years of work, but I'd hesitate to call that experience rich. Nor am I saying the author's not qualified on the topic, but the discussion does need to be developed beyond ENG-101.
I also wonder a bit about the purpose of this article. Not that it contains any errors, but what is the massage that it intends to deliver.
I find that ball valves are a very good choice for most applications for several reasons. Fully open they do have the lowest pressure drop, and fully closed they are not likely to leak. They have an additional advantage of clearly showing if they are open or closed, and when open they are quieter than most other kinds of valves. Ball valves are not a good choice for throttling applications where fine control of smaller flows is needed, in fact a ball valve used for flow control is very non-linear and likely to lead to instability if it is in a closed loop servo control application. So they don't fit everywhere, but they are a fist choice for many applications. Once again it is clear that a system designer does need to understand the individual parts of the system in order to get the desired performance at the best price.
Kevin, devices such as these form an important component in many systems that feature fluid flow. In talking about 3D printing and advanced electronics we sometimes forget that there are lots of other components that make the things we need work.
Linear guides are one of the most important components required for the design of automated or computer-controlled equipment. Aluminum profile extrusions, used for these guides, can enable designed-in functional features.
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