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Re: Question



OK, I hadn't gone through all the work to figure out the PSIG/foot of depth of water, but everyone seems to be talking thousands of PSI, not the hundreds involved in what a reasonable sub would goto..  If I built a test fixture for my boat (sub)  to simulate a trip to 400 feet I would only need to presurize it to 200psi?  I can build a tank that will handle 200psi for testing... Especially a 200psi rig for testing of windows.  I'm dumbfounded, If it's really the thousands of PSI I was thinking of.

Well onto list material :)  What testing rigs have you developed, and do any of you want to describe them or publish plans for them.

*********** REPLY SEPARATOR ***********

On 8/7/99, at 12:02 PM, Paul Suds wrote: 

>Charlie, I would highly recommend a scuba class. They cover Boyles, law, 
>Charle's law, and Dlaton's law.  Fresh water density is 62.3164 lb/ft2 at 20 
>degrees C. Saltwater is ~64lb/ft2. Divide by 144 (12inches x 12 inches), and 
>you get 0.43 psi/ft for fresh water and 0.44 psi/ft for salt water. Rule of 
>thumb that keeps you safe is: half the depth to give you psi. Example: in 
>100 ft of H2O, you have 50 psig of pressure, even though it's actually 43 to 
>44 psig. The "g" in psig is gauge pressure. That means if the pressure gauge 
>on the surface measures 0 psi, then it would read 50 psi at 100 ft of water. 
>Psia is absolute pressure. We currently have 1 atmosphere, or 14.696 psi of 
>pressure from the air over our heads. Hope this helps,
>Paul
>
>
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