Home Manuals Supplies Search Consult Contact Testing Service

Maximum Air Flow Through A Hole

I couldn't find any reference to the gate valve setting in any of the Welte references. Didn't you measure the distance before taking the valve apart? I guessing not.... Generally speaking, a gate valve (or cut-out valve) doesn't have to open any more the 1/4" to allow maximum air flow. Look at it this way, the maximum amount of air that can possibly flow 'by' the valve is equal to the square area of the hole that the valve covers. So, if the hole is 1-1/8" in diameter, the square area = (pi x r2) or 3.14159265 x .56252 = 0.9940 sq in. or 1 sq in. Now, looking at the valve, we have to consider the point where the valve seals the hole because that is the 'limiting' factor in the equation. So, if the hole has a diameter of 1-1/8", the circumference of the hole (or the perimeter) = (2 x pi x r) or 3.5342 in. Now, you have to consider that the 'perimeter' times the valve clearance is actually a rectangular area through which the air will pass. In other words, it's like a wall. So, if the valve clearance is 1/4" (0.250") and we multiply that by 3.5342", we come up with 0.8835 sq in. Oopppps. Not enough.....

Actually, the solution is to divide the square area of the hole (pi x r2) by the circumference of the hole (2 x pi x r).

pi = 3.14159265 (most people use 3.14)

Example:

d = 1"
r = .5"
pi = 3.1415

pi x r2 (area) / pi x d (circumference)

0.7854 / 3.1416 = 0.25"

Naturally, your answer will be dependent on the actual sizes of the parts.

Player Piano Reference Materials - Click Here

We Gladly Accept These Cards
Discover, VISA, MasterCard

back to top..To The Top of this Page . . . . . . . . . . . back to index ..To The HOME Page


This page was last revised July 1, 2017 by John A. Tuttle, who Assumes No Liability
For The Accuracy or Validity of the Statements and/or Opinions
Expressed within the Pages of the Player-Care Domain.
Cartoon Graphics by E7 Style Graphics (Eric Styles)


Since "Player-Care" is an internet business, I prefer that we correspond via E-Mail (click here to fill out the 'Request Form'). However, if I'm not in the middle of some other activity, you can reach me at 732-840-8787. But please understand that during the hours from 8AM-5PM EST (Mon-Sat), I'm generally quite busy. So, I probably won't answer the phone. If you get the answering machine, please leave a detailed message stating the reason for your call. Also, repeat your name and phone number clearly and distinctly. By necessity, I prioritize everything in my life. And, if you call and just leave your name and number, and ask me to call you back, it might be a day or two before I return your call. Why? Because I don't know why you want me to call and I might not be prepared to assist you in an effective and efficient manner. If you leave me an E-Mail address (which I prefer), spell it out phonetically. The more you do to help me, the more I can help you in return. Don't rush. You have four minutes to record your message.


Grand 16 IconGrand 32 Icon

407 19th Ave, Brick, NJ, 08724
Phone Number 732-840-8787
(Voicemail Only, No Texts)
Upright 32 IconUpright 16 Icon

Google Adsense Ad