[PSUBS-MAILIST] G.L. summary Pressure Hull

[Alan James]

If you have an over-pressure valve handle obstructing the 
movement of the hatch latch handle, it would need to be
spring loaded or you would create the problem of the possibility
of diving with the valve open later on.
With the G.L. qualification I mentioned of having 2 shut off valves,
I guess you could put the shut off valve at the hull & the over-pressure 
valve anywhere on a line coming from it, & use it additionally as the 
equalization valve. Possibly then place the over-pressure valve some how
 that it could be plunged as the latch handle was moved.
Alan




________________________________
 From: "MerlinSub at t-online.de" <MerlinSub at t-online.de>
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org> 
Sent: Thursday, December 12, 2013 11:05 AM
Subject: Re: [PSUBS-MAILIST] G.L. summary Pressure Hull
 


E-Mail Software 6.0
I am pretty sure GL and the other 
classes like a hatch, OP, AOP solution
without electronics a lot 
more.   

On Euronaut there is a manual ballvale as 
Overpressure valve integrate in the hatch
and a red label on the hatch handle 
"Never open before equalize". 

Its not with the rule because we assume 
the operator is able to read a red label - but for us it works. 

In 
case I had to build something with the rules I just will block with the 
ballvalve handle in close position 
the hatch handle or the latches. 

Another way could be to design the hatch latches that way on a tread 
handle 
that you have to turn the whell some turns and it gives the hatches 
only a litte opening  to equalize 
and gives the latches later 
complete free with more turns. 
In that way you can open the hatch very 
fast in case in the batterey get very hot below your feets.. 
And you can 
still blow your ears drums away in case you like that.. 

vbr 
Carsten


"Jon Wallace" <jonw at psubs.org> schrieb: 

>Advantage: ABS
>
>I think the sentence being scrutinized may perhaps just be badly
      worded.  With the exception of some intricate mechanism that
      equalizes as part of a sequence to open the hatch as Jim
      suggested, I don't see a way to comply with the requirement
      without the involvement of electronics.  Philosophically I don't
      think I want to rely on an electromagnet or boolean logic giving
      me permission to exit the vessel.  If Jim's mechanism turns out to
      be to complicated then Doug's concern is valid...remember Apollo
      1.
>
>Jon
>
>
>On 12/11/2013 4:17 PM, Alan James wrote:
>
>Hi Doug,
>>Elaborating on your idea.
>>If you had digital pressure gauges you could have a system
>>comparing the voltage of the two, & when they were in a 
>>similar range they would activate or deactivate an electromagnet
>>that pulled back a latch that was impeding the movement of the hatch
>>release mechanism. (car door lock mechanism) You would
>>need a manual over-ride. Any electronics nerd could do this easily
>>& the car lock mechanisms I've seen for round $20-
>>With the over-pressure valve set at a couple of psi you know
>>
>>that on the surface the most over pressure there could be is
>>what your over-pressure valve is set at. Under-pressure is
>>not such an issue as you won't be able to physically open the hatch 
>>if the under pressure is too much, & hence you have to equalize.
>>So I don't think it needs sophisticated monitoring. 
>>I'm not sure how much of an issue it would be if you opened your
>>hatch with a couple of psi over-pressure. Would the dome fly
>>open at 90 miles an hour, or would pressure be released incrementally
>>as the hatch dogs unlatched before fully releasing.
>>Obviously G.L. thinks this is an issue.
>>Alan
>>
> 

-- 

Carsten Standfuß
Dipl.Ing.Schiffbau @ Meerestechnik
Heinrich Reck Str.12A
18211 Admannshagen Germany

+49 (0) 172 8464 420
WWW.Euronaut.org
Carsten at euronaut.org

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