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Re: [PSUBS-MAILIST] Flat Acrylic windows and Germanischer Lloyd Rules
Hi Andy,
Andy Jensen schrieb:
>
> Germanischer Lloyd Rules for Underwater Technology
> Section III - Part 1 Appendix B Acrylic Plastic Windows
> I am trying to figure out the safty margen for the Table 2
>
> This is what I was thinking flat window
> Di 10” ,254mm internal dia
> Do 12” ,381mmexternal dia
> S 4.5” ,114.3 thick
> S/Di = .45
> On the table
> @ 24°C,75°F
> 170 bar 2400psi 5400fsw
> test depth =3500
> “safe”depth=1700
>
seems right.. (but s/di is 0,456 not 0,45.. get 116 mmm)
but 24 degree at 1700 m deep.. (5600feet)
- you want to visit vulcanos ? The temp.figure
is to calculate with : Inside sub temp + outside sub temp
divided by two. Example : Inside 21 degree and outside
(at 5600.. ) 4 degree = 21 + 4 = 25/ 2 = 12,5 degree.
> all is well
> then as I am sifting through the archive I found.
>
> "And CSSX will have two flat viewports diameter of 700/600
> with 110 mm thickness for 250 Meter (or 27,6 in /23,6 in
> with 4,3 in thickness for 820 feet) "Carsten
>
> I ran the numbers and came up with an s/D .183 on the
> table at 10°C,50°F 20 bar or 800 fsw
> Is this the safe working depth? And the pop depth would
> 2400fsw
>
(hmm.. found 0.188 on the table..)
Okay I run it with this new table (I use an old one for the earlier
calculation ) and get :
inside diameter : 600 mm
temp degree : 10 celsius
design pressure : 25 bar
and get a s/di of 0,201
so S should be 0,201 x 600 mm = 120,6 mm (and not 110..)
I don't know wich saftey margin they have but for the
pressure hullintsef they run in the area of two.
Carsten - but not any window in my vessel design now - will use some
high resulution video cameras and big TFT screens - is much cheaper,
quicker to build, can see more, can tape it, can use picture processing
software to elimate dusty water. And of course maybe more safe.
But makes sence only on bigger vessels.
> Could someone shed some light on this Please
>
> Btw I down loaded the tables from
> http://www.germanlloyd.org/infoServices/rules/pdfs/english/glrp-e.pdf
>
> Andy J