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Post by luis on Jul 8, 2020 15:06:40 GMT -8
OK, no offense meant, Luis. But you're saying just because you've been calling it an adjustable orifice for years, it must be correct. It isn't correct. If the orifice was adjustable (bigger diameter to smaller diameter), you'd be able to open or restrict the opening of the volcano. You can't (with this part). That's all I'm saying. What you're talking about is adjusting the hard seat up or down in a bore to make more or less spring tension. It's an adjustable seat. First it is not about taking offense. But, telling me that the normal usage in industry is "incorrect", well that has some issues. We are using language for communication and I thought my communication was clear enough. I have worked in too many industries (ship building, heavy metal fabrication, computer terminology, just to name a few) that totally corrupts and make their own definition of words, but they still can communicate with each other. In the English language one of the things I have learned is that the longer a term is used, the longer it will stick. Trying to say that it is right or wrong, becomes less relevant if it communicates the correct message. I always try to use the "correct" consistent terms, but I have learned that some terms change depending of the group or industry it is used in. You are correct in that the volcano orifice diameter is not adjustable (it is not like an iris in a camera), but it is well understood in this industry as an adjustable orifice. Technically it could have been called "adjustable position orifice". But for the purpose of maintaining relatively brief communication we have always taken some short cut in all industries. I do not know what your is your background, but trying to come into the scuba industry and trying to change terminology that has been used for decades is just going to be confusing. Note: I hope you never have to work in the marine industry or ship building industry... We are talking about a totally different language (and sometimes they are not even consistent between shipyards)... and don't try to tell them they are "incorrect" BTW, another standard short cut is that we normally call the "seat" the soft compliant matting surface. I normally only seen the use of the term "hard seat" on foreign regulators like Poseidon, but there may be others. Again the purpose of language is good communication. If you didn't understand what I was saying, by all means please ask and I will try to make it clear.
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Post by vance on Jul 8, 2020 15:30:23 GMT -8
Well understood in the industry does not excuse a poor description of a part. I'm sorry, but clear English is necessary for the novice to understand wtf we are talking about. I should have said "hard seat". A hard seat is the machined metal mating surface for a soft seat. These are commonly accepted terms in "industry".
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Post by nikeajax on Jul 8, 2020 15:59:48 GMT -8
I gotta agree with PY on this one, even if it's "industry standard". An adjustable orifice would be similar to a "iris diaphragm" as used in photography/optic: en.wikipedia.org/wiki/Diaphragm_(optics)I think "adjustable-valve" is a much better descriptor, but to paraphrase Luis, it's a whole different language I'm sure CJ could give us legal-terms that would make our brains melt JB
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Post by luis on Jul 8, 2020 16:14:09 GMT -8
It isn't correct. If the orifice was adjustable (bigger diameter to smaller diameter), you'd be able to open or restrict the opening of the volcano. You can't (with this part). That's all I'm saying. What you're talking about is adjusting the hard seat up or down in a bore to make more or less spring tension. It's an adjustable seat. I am not going to waste any more time on a language discussion. But since you had to mention “restriction”… Just for the record, when you adjust the volcano orifice position, you are indirectly also adjusting the available or potential restriction of the opening. The flow restriction opening of concern associated with the volcano orifice is not in the area of the circular opening of the hole or the bore diameter. The relevant flow restriction, where the pressure discontinuity occurs (and the associated shock wave and pressure drop), takes place is in the perimeter, in the gap created between the volcano orifice and the soft seat. Adjusting the position of the volcano orifice not only can normally affect the spring loan, but it can also affect the available restriction. Normally this is not ever addressed since most fully open demand valve have such a low restriction that they will empty a cylinder in a few minutes. I am not just bringing in a technicality just for a debate. I just thought it was an interesting point of observation. I hope this is clear, but if it is not…
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Post by vance on Jul 8, 2020 16:20:42 GMT -8
OK, whatever.
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Post by vance on Jul 8, 2020 16:23:48 GMT -8
F'in A.
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Post by james1979 on Jul 8, 2020 16:45:12 GMT -8
I stand by "Orifice of Adjustable Position"!
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Post by vance on Jul 8, 2020 16:55:45 GMT -8
S'truth.
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Post by vance on Jul 8, 2020 17:24:24 GMT -8
This is a simple matter. Either the orifice (opening) is adjustable, or the hard seat (sealing surface) is. Take your pick.
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Post by crabbyjim on Jul 8, 2020 19:12:07 GMT -8
I gotta agree with PY on this one, even if it's "industry standard". An adjustable orifice would be similar to a "iris diaphragm" as used in photography/optic: en.wikipedia.org/wiki/Diaphragm_(optics)I think "adjustable-valve" is a much better descriptor, but to paraphrase Luis, it's a whole different language I'm sure CJ could give us legal-terms that would make our brains melt JB There are legal terms which have a specific meaning (terms of art) that don’t mean the same thing as those words in common speech. Luis is a professional and as he explained, professionals speak the language of their profession. Phil’s comments are well taken but are unlikely to change the established industry terminology. This thread is about a modification of an old regulator to make it a better breather. Let’s leave it at that.
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Post by vance on Jul 8, 2020 19:27:52 GMT -8
Amen.
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Post by nikeajax on Jul 9, 2020 10:59:08 GMT -8
There are legal terms which have a specific meaning (terms of art) that don’t mean the same thing as those words in common speech. Luis is a professional and as he explained, professionals speak the language of their profession. Phil’s comments are well taken but are unlikely to change the established industry terminology. This thread is about a modification of an old regulator to make it a better breather. Let’s leave it at that. Hmmmmm... Firstly, it isn't a "waste of time": what Phil brought up were very valid points... Those points help to evaluate the process of what were doing-- LEARNING!
No, they are not going to change the "language of the industry": any professional can spew out highly technical and esoteric jargon, but will the average person understand them? Please remember you yourself CJ have asked many, many times to simplify what we were talking about, and we have patiently reworded our answers. There's nothing wrong with a little "mental jousting", especially when it allows us to examine the process of how and why things work. As someone with a severe learning disability I appreciate being able to look at things from a different perspective because it allows me to do things that other people can't. There are things that I can't do like other people, so I do them my way, and when they work, I share them. Here are two examples: And lastly, there are so, so few post and participation on this forum I heartily welcome anyone writing anything, especially when it lets me/us learn something new. Jaybird
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Post by nikeajax on Jul 10, 2020 8:43:05 GMT -8
Someone please enlighten me: I'm failing to see why this type of valve provides more efficient/better breathing characteristics than a regular/traditional poppet-valve?
JB
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Post by james1979 on Jul 10, 2020 12:27:43 GMT -8
Someone please enlighten me: I'm failing to see why this type of valve provides more efficient/better breathing characteristics than a regular/traditional poppet-valve? JB JB, This fitting isn't changing the type of valve, what it is doing is adding a point of adjustment. In a traditional downstream poppet valve, you have 3 forces affecting the poppet; Spring preload holding it shut, Intermediate pressure trying to open it, and the lever levering it open. The closer IP is to spring preload, the less force needed on the lever to open the valve.
The spring preload is defined by the spring strength (or rate), length, and the distance from the orifice (or hard seat) and where the back of the spring seats in the valve body.
In an ordinary 1058 second stage (or Scubapro 108, or any similar reg), that distance from orifice (hard seat) is fixed... so your only breathing effort adjust available is to raise the IP to offset the spring preload more. With this fitting we can set the spring preload to nearly anything we want, which means we can tune it for as easy or difficult of cracking pressure as we want, independent of the IP. I think that made sense... but I usually think I do even when I don't! In theory, you might have a Conshelf (pick your number) that has the perfect match of specific tolerance variations that it will breathe optimally at the IP you want... but that is vanishingly rare due to minor part variations.
Respectfully, James
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Post by scubalawyer on Jul 10, 2020 12:38:05 GMT -8
Someone please enlighten me: I'm failing to see why this type of valve provides more efficient/better breathing characteristics than a regular/traditional poppet-valve? JB JB, This fitting isn't changing the type of valve, what it is doing is adding a point of adjustment. In a traditional downstream poppet valve, you have 3 forces affecting the poppet; Spring preload holding it shut, Intermediate pressure trying to open it, and the lever levering it open. The closer IP is to spring preload, the less force needed on the lever to open the valve.
The spring preload is defined by the spring strength (or rate), length, and the distance from the orifice (or hard seat) and where the back of the spring seats in the valve body.
In an ordinary 1058 second stage (or Scubapro 108, or any similar reg), that distance from orifice (hard seat) is fixed... so your only breathing effort adjust available is to raise the IP to offset the spring preload more. With this fitting we can set the spring preload to nearly anything we want, which means we can tune it for as easy or difficult of cracking pressure as we want, independent of the IP. I think that made sense... but I usually think I do even when I don't! In theory, you might have a Conshelf (pick your number) that has the perfect match of specific tolerance variations that it will breathe optimally at the IP you want... but that is vanishingly rare due to minor part variations.
Respectfully, James
Nice description. I love my SP109's. I have the same in-line adjustment tool shown earlier. M
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