hosted on condor3913
 Mechanical Music Digest  Archives
You Are Not Logged In Login/Get New Account
Please Log In. Accounts are free!
Logged In users are granted additional features including a more current version of the Archives and a simplified process for submitting articles.
Home Archives Calendar Gallery Store Links Info
MMD > Archives > February 2018 > 2018.02.26 > 02Prev  Next

Valve Terminology
By John A. Tuttle

Hi All,  With all of the work I'm doing with valve facing materials,
I've also been doing a lot of reading.  One thing that puzzles me
somewhat are the various terms I've found.  There's 'the vacuum side'
and 'the atmosphere side'.  There's the 'upper' and the 'lower'.  And,
there's the 'top' and the 'bottom'.

Personally, I've always referred to the facings as 'intake' and 'exhaust'.
My thinking is simple; 'intake' lets the good stuff 'in' and 'exhaust'
lets the bad stuff 'out'.  The good stuff is the vacuum.  The bad stuff
is the atmosphere.

Now I realize the you don't actually 'let vacuum in' or 'let atmosphere
out'.  In every case, the atmosphere is always trying to equalize the
negative air pressure.  Not the other way around.

I'm reminded of something someone said: If a window gets shot out of
an airplane at 35,000 ft, things don't get sucked out of the airplane.
They get blown out by the comparatively positive pressure inside the
plane.  And as soon as the pressures equalize -- well, you die in less
than 30 seconds unless you're really, really lucky... but that's a
whole other story.  But I digress...

What I'm really looking for is an explanation for the terms 'upper' and
'lower' or 'top' and 'bottom'.  The reason I'm asking is because quite
a large number of player systems have horizontally inclined valves.
So, there is no 'upper', 'lower', 'top', or 'bottom'.  And, if 'upper'
and 'top' refer to the atmosphere side and 'lower' and 'bottom' refer
to the vacuum side, where is that explained so a novice can find it?

By the way, if this seems like a dumb question, I would remind you that
Carl Sagan, in his work 'The Demon-Haunted World: Science as a Candle
in the Dark,' said: "There are naive questions, tedious questions,
ill-phrased questions, questions put after inadequate self-criticism.
But every question is a cry to understand the world.  There is no such
thing as a dumb question."

John A Tuttle
Brick, New Jersey, USA

(Message sent Tue 27 Feb 2018, 00:51:13 GMT, from time zone GMT-0800.)

Key Words in Subject:  Terminology, Valve

Home    Archives    Calendar    Gallery    Store    Links    Info   

Enter text below to search the MMD Website with Google

CONTACT FORM: Click HERE to write to the editor, or to post a message about Mechanical Musical Instruments to the MMD

Unless otherwise noted, all opinions are those of the individual authors and may not represent those of the editors. Compilation copyright 1995-2023 by Jody Kravitz.

Please read our Republication Policy before copying information from or creating links to this web site.

Click HERE to contact the webmaster regarding problems with the website.

Please support publication of the MMD by donating online

Pay via PayPal

No PayPal account required

Translate This Page