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Re: [PSUBS-MAILIST] Main ballast.



Hi Marco,

I don't know about best. But see http://www.psubs.org/faq.html#ballasttankdesign
for a solution.

Regards,
Ray

> User-Agent: Microsoft-Entourage/9.0.2509
> Date: Sat, 24 May 2003 18:16:36 +1200
> Subject: Re: [PSUBS-MAILIST] Main ballast.
> From: Marco <marco@zeeman.co.nz>
> To: <personal_submersibles@psubs.org>
> 
> > To the Ballast experts...
> > 
> > Does anyone have a good schematic available on this subject as that would
> > answer many questions for those of us wondering the best ballasting 
solution,
> > ensuring controlled ascent.
> > 
> > Im working on a dry ambient and am keen to know any new tricks or
> > techniques...
> > 
> > Kind Regards
> > 
> > 
> > Marco
> > 
> > 
> > 
> > 
> > 
> > 
> >  Yup, agreed.
> > 
> > "Dan H." <JMachine@adelphia.net> wrote:
> >> Chris, 
> >> I'm sure you could give it a pop of air and clear the lines if you have it
> >> plumbed in that way.  The good thing is, if it's a problem, it won't 
prevent
> >> you from surfacing,  only submerging.
> >>  
> >> Dan H.
> >> ----- Original Message -----
> >>> From: Chris Nugent <mailto:dirkpitt77@yahoo.com>
> >>> To: personal_submersibles@psubs.org
> >>> Sent: Friday, May 23, 2003 7:52 PM
> >>> Subject: Re: [PSUBS-MAILIST] Main ballast.
> >>> 
> >>>    Dan,
> >>>  
> >>>    Yep, I'm still with ya.  I think I'll have to find a way to keep those
> >>> lines clear, because in my design it's more convenient to have most of my
> >>> piping and valves in the main hull as opposed to the conning tower.  I
> >>> wonder if you could use compressed air to blow them out if  you run into
> >>> that situation?  Hmm...
> >>>     Anyway...hey, thanks for the help.  Very illuminating.
> >>>  
> >>>     Chris
> >>> 
> >>> "Dan H." <JMachine@adelphia.net> wrote:
> >>>> Chris,
> >>>>  
> >>>> Your right in what you say about the piping not having to all be above 
the
> >>>> tank if it's full of air.  But, if your piping is routed to a point below
> >>>> the top of your MBT and you get water in the pipe, which is sure to 
happen
> >>>> when filly blowing the tank, the water held in the pipe will be heavier
> >>>> then the air that is trying to be forced out.
> >>>>  
> >>>> I'm not doing a good job with this explanation! Sorry
> >>>>  
> >>>> Think of what happens if you siphon with a hose.  If part of the hose has
> >>>> air in it you can't get the siphon going.  In this case, if the lower 
part
> >>>> of the piping has water in it, it till take more pressure in the MBT to
> >>>> blow the low lying water out and allow the air to pass through.  Since 
the
> >>>> only pressure is the head of water, it can't lift a trapped column of 
water
> >>>> higher then it self.
> >>>>  
> >>>> Agree?????
> >>>>  
> >>>> Hope I made enough sense for you to follow my thinking.
> >>>> Dan H.
> >>>> ----- Original Message -----
> >>>>> From: Chris Nugent <mailto:dirkpitt77@yahoo.com>
> >>>>> To: personal_submersibles@psubs.org
> >>>>> Sent: Thursday, May 22, 2003 8:40 PM
> >>>>> Subject: Re: [PSUBS-MAILIST] Main ballast.
> >>>>> 
> >>>>>     "The vents for the fore and aft soft MBT have to be mounted at the 
top
> >>>>> of the tanks in order to release the air above the water.  Since the 
MBT's
> >>>>> top is the same height as the top of the hull, the piping and valves had
> >>>>> to be located at the height of the conning tower. "
> >>>>>  
> >>>>>  
> >>>>>      Ok, so if the sub is sitting on the water on the surface, the air 
in
> >>>>> the MBT's should be under some pressure since the weight of the sub is
> >>>>> forcing it down, and thus forcing water into the bottom of the MBT's, 
and
> >>>>> thereby displacing the air in them and compressing it until it achieves
> >>>>> equilibrium and the sub floats, right?  I understand why the valve has 
to
> >>>>> be at the top of the MBT, but your piping doesn't have to be at the same
> >>>>> level as the valve, right?  If I reckon right, the somewhat pressurized
> >>>>> air in the MBT's, once the valve is opened, should rush right out no
> >>>>> matter where your piping is, as long as the MBT is able to flood
> >>>>> completely, right?
> >>>>>     At the depths I'm aiming for (ummm....50 feet?)   I hadn't thought
> >>>>> that my valve configuration would pose a problem as far as withstanding
> >>>>> the pressures involved.  I may re-do it anyway though.
> >>>>>  
> >>>>> Chris
> >>>>> 
> >>>>> "Dan H." <JMachine@adelphia.net> wrote:
> >>>>>> Chris,
> >>>>>>  
> >>>>>> First I have to say, I didn't design it but from what I see in the over
> >>>>>> all design, and knowing the designer, I think the valving was done this
> >>>>>> way for safety and simplicity.  All other valves except these vent 
valves
> >>>>>> are located within the hull.
> >>>>>>  
> >>>>>> Since each of these vent valves run from an external tank to outside 
the
> >>>>>> hull, each valve would have two through hulls for the piping.  Better
> >>>>>> three, quarter turn through hulls, then six pipe through hulls, more
> >>>>>> fittings and a still three valve stem seals inside the hull.
> >>>>>>  
> >>>>>> The vents for the fore and aft soft MBT have to be mounted at the top 
of
> >>>>>> the tanks in order to release the air above the water.  Since the MBT's
> >>>>>> top is the same height as the top of the hull, the piping and valves 
had
> >>>>>> to be located at the height of the conning tower.  It would be 
cluttered
> >>>>>> to have these valves and their piping inside the conning tower.  On 
both
> >>>>>> K subs, the MBT vent valves are taken apart and altered with long stems
> >>>>>> that screw right on to a special threaded replacement for the packing 
nut
> >>>>>> that is welded in through the conning tower wall.  It makes a clean
> >>>>>> package and has double O-ring seals for added safety.  Even if the 
valves
> >>>>>> get sheared off, the stems have shoulders that prevent then from 
blowing
> >>>>>> through to the inside.
> >>>>>>  
> >>>>>> The less holes in the hull the better.
> >>>>>> ----- Original Message -----
> >>>>>>> From: Chris Nugent <mailto:dirkpitt77@yahoo.com>
> >>>>>>> To: personal_submersibles@psubs.org
> >>>>>>> Sent: Wednesday, May 21, 2003 10:33 PM
> >>>>>>> Subject: Re: [PSUBS-MAILIST] Main ballast.
> >>>>>>> 
> >>>>>>>    Hey Dan,
> >>>>>>>  
> >>>>>>>      Just wondering, what is the reason for mounting the valves 
external
> >>>>>>> to the hull on the K-350?  Is it because it's easier to put the
> >>>>>>> actuating shafts in a thru-hull and run that through the hull to the
> >>>>>>> valve, rather than mount the valves inside the hull with the air lines
> >>>>>>> and air supply and run the air lines through the hull to the MBT's?  
Or
> >>>>>>> something else I missed?
> >>>>>>>  
> >>>>>>>               Thanks,
> >>>>>>>  
> >>>>>>>                      Chris Nugent
> >>>>>>> 
> >>>>>>> "Dan H." <JMachine@adelphia.net> wrote:
> Pierre,
> 
> On the K-350 the "hard ballast tank" is located under the hull. There is a
> shaft that runs through the hull with a flex coupling on it that is directly
> above a quarter turn valve on the sea water opening of the hard ballast
> tank. A quarter turn of this threw hull shaft turns the ball valve
> directly.
> 
> The "soft ballast tanks" are of fiberglass and are located fore and aft.
> They are opened to sea water all the time. The vent air is controlled with
> quarter turn ball valves located on the conning tower. The valves are also
> located external but are altered with special long stems so they are
> controlled from inside the conning tower. The valves are connected to the
> top of the tanks with tubing. The valves are mounted high in the tower and
> vent from the tops of the tanks.
> 
> Hope this is what your looking for.
> Dan H.
> ----- Original Mess a! ! ! ! ge -----
> From: "pierre&marie"
> To: 
> Sent: Wednesday, May 21, 2003 6:31 PM
> Subject: [PSUBS-MAILIST] Main ballast.
> 
> 
> > Hi People!
> >
> > How do you "plug" the main ballast tank to adjust buyoncy (man, that word
> is
> > killing me...)
> >
> > I'm trying to figure a way to use a 5/3 pneumatic valve. It would be easy
> to
> > use to adjust bouyancy. But, I can't have the plumbing right at the
> moment.
> >
> >
> > Any advise? Somebody know how it's done in a K-350?
> >
> > Thanks!
> >
> > Pierre Poulin
> > "At last the sun is here!"
> >
> >
> >
> 
> 
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> > 
>