Re: [PSUBS-MAILIST] viewport calcs

Brian

the material removed for the penetration has to be replaced for the reinforcement see busby. the landing flange at 1/2 the thickness of the port will suffice for the strength needs. the exterior rim depth is determined by the radius of the hull and the dia of the penetration allowing for welding area. my port designs use 200% replacement as a minimum for strength.

rick m

----- Original Message -----

From: Brian Cox

To: personal_submersibles@psubs.org

Sent: Wednesday, December 28, 2005 12:05 AM

Subject: Re: [PSUBS-MAILIST] viewport calcs

Hi Rick,

My tiny pea brain finally gets these figures, I understand the thickness of window - to - diameter of window ratio limits,

I don't see where they talk about the metal viewport housing though? It doesn't seem like they are giving any dimensions for the metal. On page 38, under viewport flanges, they talk about dimensioning the flanges but they don't give you any actual numbers. Obviously the flange has to be the thickness of the acrylic in that dimension. And I get the retaining ring and the bevel, and the o ring tolerances. I haven't seen any numbers for the thickness of the flange in the other dimensions. Is there a thickness to diameter ratio for the metal as well?

Thanks

Brian

----- Original Message -----

From: rick miller

To: personal_submersibles@psubs.org

Sent: Monday, December 19, 2005 13:59

Subject: [PSUBS-MAILIST] viewport calcs

from pvho-1

for a standard round flat viewport

thickness greater than or equal to .5 inch

t/dia greater than or equal .125

design pressure * cf of six = critical pressure

do= dia outside

di=dia inside of seat
do/di >or = 1.25

for a 1000 ft depth design the t/di greater than or equal to.25 ie a two inch thick view port will have a max di of 8 and and be 10 inch do

for a 500 ft depth design the t/di greater than or equal to.195 ie a two inch thick view port will have a max di of 10.25 and and be 13 inch do

for a 250 ft depth design the t/di greater than or equal to.165 ie a two inch thick view port will have a max di of 12.12 and and be 15.15 inch do

i hope that this helps

rick m