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Old 23 November 2005, 05:35   #21
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Quote:
Originally Posted by jwalker
Anyone know what pressure blow-off valves blow off at?
Seems like any pressure from 1psi to 10 psi Look at this

Been thinking about these myself and I canít decide if I need one in every chamber
My thinking is that if I start inflating at the front of the boat the inter-chamber cones point rearwards so by the time it get to the rear chamber on one side it is a cone smaller than its total size so any expansion can take place into the chamber before it. Does this make sense or am I missing the point Des
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Old 23 November 2005, 05:37   #22
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I used to have a quicksilver SIB. You had to seriosuly inflate that if you followed the instructions. From memory the tubes were about 2.5 and the floor was even more, possibly 4. Codders can correct me as he has this boat.
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Old 23 November 2005, 05:40   #23
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Quote:
Originally Posted by roycruse
Are you sure it wasnt just the floor that was supposed to be at 2.5 PSI and not all the tubes.

I used to have a Metzeler SIB that had a honey comb deck and it had to be at a much higher pressure than the tubes.
No! their quote to me was "pump the keal as hard as you can get it & the rest of the tubs to 2.5psi"
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Old 23 November 2005, 05:45   #24
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Pressure release valves...

I was thinking about fitting these to my tubes and approached Henshaw Inflatables. Supplying them was no problem as they're a stock item, but when I spoke to Kevin, the factory manager, he reckoned that they're not worth fitting in our climate, and could even be less than useful inasmuch as they'd release pressure on a hot day, but if left unattended, the boat would end up being underpressured when the temperature dropped. He also said that although the P22 should be pumped to 2psi, the tubes are designed to be happy when things heat up and the pressure rises to as much as 3.5psi.

Perhaps someone with an Avon should speak to the factory for their advice?
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Old 23 November 2005, 06:31   #25
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Quote:
Originally Posted by Scary Des
Seems like any pressure from 1psi to 10 psi Look at this

Been thinking about these myself and I canít decide if I need one in every chamber
My thinking is that if I start inflating at the front of the boat the inter-chamber cones point rearwards so by the time it get to the rear chamber on one side it is a cone smaller than its total size so any expansion can take place into the chamber before it. Does this make sense or am I missing the point Des
Ta. It looks as though I need to find out the spring colour. Your second link here also had a PDF which gave the list of spring colours against pressures from 0.5 - 13.4psi.

With the tube baffles I work from the rear inflating both sides. The cones will be pushed forward, the next will also be pushed forward as will the next. Finally, I inflate the front section to be harder than I'd made the others. This will pressurise all the other sections to the same pressure by forcing the cones back toward their respective sections. It also allows a bit of deflation of any section whilst keeping all the pressures the same because the cones can move to compensate.
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Old 23 November 2005, 06:42   #26
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Quote:
Originally Posted by jwalker
..
With the tube baffles I work from the rear inflating both sides. The cones will be pushed forward, the next will also be pushed forward as will the next. Finally, I inflate the front section to be harder than I'd made the others. This will pressurise all the other sections to the same pressure by forcing the cones back toward their respective sections. It also allows a bit of deflation of any section whilst keeping all the pressures the same because the cones can move to compensate.
There ya go again, JW... thinking things through properly... you'll wear your brain out at this rate.... I intend making my brain last as long as possible, by treating it gently....
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Old 23 November 2005, 06:45   #27
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Quote:
Originally Posted by jwalker
......With the tube baffles I work from the rear inflating both sides. The cones will be pushed forward, the next will also be pushed forward as will the next. Finally, I inflate the front section to be harder than I'd made the others. This will pressurise all the other sections to the same pressure by forcing the cones back toward their respective sections. ........
So with one pressure relieve valve in each of you rear chambers you could de-pressurise all your chambers by the volume of the inter-chamber cones Or am missing something
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Old 23 November 2005, 06:51   #28
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Quote:
Originally Posted by Scary Des
So with one pressure relieve valve in each of you rear chambers you could de-pressurise all your chambers by the volume of the inter-chamber cones Or am missing something
There not actually cones though are they ? They are flat baffles - which means the additional volume available will only be the amount that that baffle can deform - which i would imagine would only allow or a few litres - or in other words a very small percentage of the total volume of a chamber.

I dont know for sure - but my guess would be that this would not supply sufficient protection.
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Old 23 November 2005, 07:01   #29
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Quote:
Originally Posted by roycruse
There not actually cones though are they ? They are flat baffles.
I wouldn't bo too adamant about that, if I were you.

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Old 23 November 2005, 07:06   #30
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Quote:
Originally Posted by jwalker
I wouldn't bo too adamant about that, if I were you.

I wasnt - note the question mark - I was actually asking a question !!!
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