What¦s the best possible air valve to be installed on a basketball?

[Felipe28]

The basketballs are not for playing but for engineering purposes and they need to lose as little air as possible. My concern is that the usual valves used in these balls are not that good in preventing the air leaking. Can another valve, like tire valves, be installed in a ball when it is manufactured?

 

[Felipe28]

Yes, no problem with protuding valves as long as they are better than the usual ones, because at least in the usual ones the protusion can bu cut and a tire patch can be glued above it.

 

[HDS]

Just use an inner tube. It already has the valve.

 

[Felipe28]

Thanks HDS, will check. Better that the Schrader valve?

 

[IRstuff]

Almost all inner tubes use Schrader valves, at least in the US. Presta valves are used on high-end bicycle inner tubes.

TTFN

FAQ731-376

 

[Felipe28]

IRStuff, so inner tubes would be better than Schrader valves, by having one inside?

 

[IRstuff]

I don't know about "better" since it's unclear whether a bare inner tube meets all your other requirements; it's just that an inner tube comes with a Schrader valve already installed.

TTFN

FAQ731-376

 

[unclesyd]

Here is the Schrader web site. I have use a high pressure Schrader Valve to 1500 psig.

http://www.schrader-bridgeport.com/index.php?option=com_sobi2&Itemid=59

Have you thought about something like these air bladders, there are numrous manufacturers?

http://www.martinrubber.com/accumulator_bladders_and_other_custom_rubber_bladders.php

 

[byrdj]

could the valves be outside the pressure vessel, with a seal around the schaider valve (like an accumulator bladder) then the charge could be checked with out opening the vessel

 

[Felipe28]

byrdj good suggestion but the fact that I introduce the balls is to exactly be the competition of the bladders. Yes, you can recallibrate the air withouth opening the tank (as long as by pressing the valve, water doesn´t come out) but if the bladder blows up you have no protection. The balls don´t have that problem but there is the problem that I am trying to solve of preventing as much as possible to air leaking in the balls.

 

[unclesyd]

You might want to look at some of the closed cell foams, either to use alone like a boat fender or some type of inject able to fill your basketball.
If you use it as a fill you could use open cell foam.

http://www.closedcellfoams.com/polyethylene.html

 

[Felipe28]

IRStuff, sorry, "better" is very abstract. What I meant with "better" is a valve that makes it more difficult for the air to escape. I ll check on inner tubes, thanks!

Unclesyd, the thanks for the sggestion but I would answer with the same previous message to "byrdj"

 

[rb1957]

there's some language (ESL) issues here ... an "inner tube" is just a bladder (or a ball) for holding air, typically in a tire, often seen as floatation devices.

schrader valves are typical tire valves. presta valves are more expensive (better?) usually seen on bicycle tires that have a mechanical locking feature.

i think you need a flexible bladder to react to the pressure pulses from water hammer. have you experimented with typical valved bladders and found them to be unacceptable ? or are you just trying to anticipate a leakage problem ? is it critical to your application that no (none, nada) air escapes into the fluid ? (i can see why) could you put an airfilled bladder inside a fliud filled bladder (which would act as a secondary containment and still might be flexible enough) ??

 

[Felipe28]

rb1957, if the balls work and I manage to prevent the air leaking in a good deal, there won´t be need for bladders anymore (too risky if they blow up). This is aimed at getting rid of them. So it is critical to avoid these leaking as much as possible.

 

[rb1957]

ok, you want a single wall flexible container of gas, so that it'll compress when acted on by an external pressure pulse , yes?

and you're talking to someone about making these containers (balls, bladders, inner tubes, whatever) ... don't they have suggestions and experience ?

i'd've thought that you'd've to be very strict on the leakage, so as not to pollute your fliud (i'm assuming you've got a hydraulic system or something). how does your fluid/system tolerate gas ? there are two ways to achieve a very good seal ... 1) a single virtually perfect seal, or 2) two pretty good seal in parallel (a container in a container). there are lots of ways to seal a container, schrader and presta are two common types, talk to a valve manufacturer.