just use a needle valve problem solved
HP hose with adaptor to lp port
- Thread starter Anthony A.
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OP
Anthony A.
Contributor
Just checked my first stage that i intended to use for this and its a piston so no way getting that ip that low. I guess the 2 lpm flow restrictor + needle valve is the way to go. Good info on the flow rate of a hp hose on an lp port.
Thanks again guys for the help.
Thanks again guys for the help.
scubafanatic
Contributor
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Good luck on your secret military experiment, you have just missed this year's DEMA show but guess we'll see your prototype do hicky next year ?
A needle valve is the way to go. No need to reinvent the wheel.
Just for reference, most needle valves used on rebreathers "close" at 0.2LPM. They never close all the way, it protects the orifice and allows for O2 flow no matter what. Find Chris Kennedy on facebook and ask him for the swagelok part number he uses in his needle valve. He's a nice guy, I'm sure he'd help.
No need to adjust IP, they use a normal LP or inflator hose, and if you use a BC hose on the output side of the reg, and put a BC connector on the flowmeter (something like a Dwyer), and you can dial it exactly where you want it.
Just for reference, most needle valves used on rebreathers "close" at 0.2LPM. They never close all the way, it protects the orifice and allows for O2 flow no matter what. Find Chris Kennedy on facebook and ask him for the swagelok part number he uses in his needle valve. He's a nice guy, I'm sure he'd help.
No need to adjust IP, they use a normal LP or inflator hose, and if you use a BC hose on the output side of the reg, and put a BC connector on the flowmeter (something like a Dwyer), and you can dial it exactly where you want it.
In response to defend-able claims: you'll be suprised to find a 'regular' HP hose we normally adapt with a spool for our SPG is designed for a SAE Straight Thread 7/16-20In fitting which is horribly common pipe fitting and seals as intended.
I didn't post in all caps, but here's a photo in support of my claim:
In buying a needle valve, perhaps
the information above might be helpful. If it doesn't need to survive saltwater there may be inexpensive solutions but here's a common one:
specs for push button valve? - Page 2
Realize this isn't in the DIY section but seems like a fun diy project. I'm just running with it.
Cameron
W W Meixner
Banned
Cameron...
Regardless of what the threaded fitting(s) may or may not fit...a HP hose manufactured to be used in the scuba industry for a submersible pressure gauge is the products engineered...tested...intended...purpose...and should be its sole use and purpose...
You could probably cobble together enough adapter fittings to use a HP scuba hose for any number of unintended purposes for any number of unintended industries...the question is should you...or would you...the correct answer is ''you should not''..
I'm seeing an over-abundance of questions looking for help to either adapt a scuba part for an unintended purpose...mostly to be used for something other than scuba diving...as well as an over abundance of questions looking for help to adapt a non scuba diving related item/part to be used in the scuba industry...one recent example is a request asking for help to modify a dromedary water bag...intended to be used to carry drinking water for camping and hiking into a BCD device...another was a question looking for help to cobble together some sort of clear plastic pressure vessel...
Instead of heading the originator of these questions down the road to disaster with all kinds of responses you have no authority to make...all of these questions should be referred back to the manufacturer of of component in question...
Ask any manufacturer of a HP scuba hose if this part should be used or ''adapted'' for any other purpose...you know what the answer is going to be...and unless you're a manufacturers representative of the component or part being queried...your response should always be to ''refer back to the manufacturer''...
You have no authority...legal or otherwise...from anyone!!..to respond any other way...
Dive Safe...
Warren
I think you may be mistaking the cart for the horse in this situation.
We use HP industrial fittings and hoses and need an adapter to use it with our SPG. It's a SAE Straight Thread 7/16-20In fitting on the end and needs an a spool added to adapt to our scuba application not the other way around.
I need no authority beyond basic human freedoms to test out ideas and talk freely about the results online. There certainly aren't scuba police involved.
Am I misunderstanding your intent?
Cameron
OP
Anthony A.
Contributor
Im an undercover scuba office Cameron..... BUSTED!!!
Ok in all seriousness, if I were to go to home depot and get a brass adaptor to use for something other than the "intended purpose" of connecting a threaded plumbing pipe to it, clearly the manufacturer would say dont do it due to legal consequences. At the end of the day, a fitting will work as long as you dont exceed its rated pressure, etc. If I were to use that fitting on a garden hose to water my plants, im not going to die nor would I need an ok from the manufacturer to do so. If that were the case, DIY would be illegal and there would be no inventions, past or present. Ask the Russians how they were able to make radios and other electronic inventions during the cold war from a shoe box full of strings, wires and old parts.
This is a simple project of basically using a scuba hose to exhaust air out of a tank so a meter can read its oxygen level. I really dont see the scare of adding a fitting to a hose.
Ok in all seriousness, if I were to go to home depot and get a brass adaptor to use for something other than the "intended purpose" of connecting a threaded plumbing pipe to it, clearly the manufacturer would say dont do it due to legal consequences. At the end of the day, a fitting will work as long as you dont exceed its rated pressure, etc. If I were to use that fitting on a garden hose to water my plants, im not going to die nor would I need an ok from the manufacturer to do so. If that were the case, DIY would be illegal and there would be no inventions, past or present. Ask the Russians how they were able to make radios and other electronic inventions during the cold war from a shoe box full of strings, wires and old parts.
This is a simple project of basically using a scuba hose to exhaust air out of a tank so a meter can read its oxygen level. I really dont see the scare of adding a fitting to a hose.
W W Meixner
Banned
Cameron...and others...
Not wishing to take this discussion any further...I clearly know the difference between horses...carts and their intended order...
I also know the difference between bags intended to hold drinking water and BCD's intended to be used at depth for scuba diving...as well as pressure hoses intended for one purpose and being altered to be used for something else...and finally whether or not it is a sound decision to offer suggestions as to how one is to proceed in the ''home'' fabrication of a ''clear plastic'' pressure vessel...
There are all kinds of scuba industry products on the market for what I believe may be the intended use of this cobbled together contraption...IP Gauges/Flow Meters/Oxygen Analyzers/Tank Pressure Gauges...etc...
Please feel free to proceed accordingly and to make as many suggestions as you wish regarding makeshift adaptions...just make sure you don't end up solely or partly responsible for a bad outcome...
Dive Safe...
Warren
Bob DBF
Contributor
That fitting was used for the first SPG's, which had the hose fitting at the back and no need for a swivel. When the bottom fittings were made the swivel was also made so they could be faced conviently when used. The actual fitting on the SPG's were the same and older hoses could be use with new SPG's. Industrial standards being what they are, I'll bet they are still interchangeable, although I haven't rooted through my dive locker to check.
Like modifying a natural gas regulator to breathe air underwater, we all know how that turned out.
Bob
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