Basic CPVC launcher - pressure relief question

Discussion about Compressors, hose, pipes, fittings, launchers, release mechanisms, and launch tubes.
jr_can
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Basic CPVC launcher - pressure relief question

Post by jr_can »

Just looking for some input on a VERY basic CPVC launcher. I built one 2 years ago for the kids and they love it. Someone asked me to build two of them for a summer camp. I'm considering if I should integrate a 75 or 100 PSI pressure relief valve for safety. Will a standard water heater relief valve work?

Attached is pic of my first attempt. I will be moving to a T shaped base and the tire pump will attach to the end of the T on a small upright to put kids farther away. Looking for cheap air hose to move the pump even farther back for safety.

Thanks for any assistance

JR
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Basic CPVC launcher
Basic CPVC launcher
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jr_can
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Re: Basic CPVC launcher - pressure relief question

Post by jr_can »

Seems CPVC has become extremely rare in the last 2 years! anyone using another material as a substitute? PVC? PEX? Not sure either of these will work with the heat and squish method to create a seal for the bottle...
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Nick B
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Re: Basic CPVC launcher - pressure relief question

Post by Nick B »

I wouldn't bother.


Not much danger in pressures below 120.


cheap air hose,

ice maker water supply tubing.
Nick and Dad B.
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U.S. Water Rockets1
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Re: Basic CPVC launcher - pressure relief question

Post by U.S. Water Rockets1 »

jr_can wrote:Just looking for some input on a VERY basic CPVC launcher. I built one 2 years ago for the kids and they love it. Someone asked me to build two of them for a summer camp. I'm considering if I should integrate a 75 or 100 PSI pressure relief valve for safety. Will a standard water heater relief valve work?

Attached is pic of my first attempt. I will be moving to a T shaped base and the tire pump will attach to the end of the T on a small upright to put kids farther away. Looking for cheap air hose to move the pump even farther back for safety.

Thanks for any assistance

JR
You can use any regular plumbing valve if you want to have a "dump" valve to abort the launch. A water heater safety valve would work as a safety, but the rockets made from bottles may explode before the water heater valve goes off.
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jr_can
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Joined: Fri May 11, 2012 10:27 am

Re: Basic CPVC launcher - pressure relief question

Post by jr_can »

It was more to reduce liability from kids trying to purposely over-pressurize the system. Seems a pressure relief valve is set for 75 PSI (75-150 PSI in the specs) so it may be a bit under pressure.

Still trying to track down schedule 40 PVC. Painfully difficult. I just did a quick search, can Schedule 80 be used instead? Cost is more, but it is available. If the O.D. is the same, the fittings would be no different. I only need around 12ft of pipe to build a single launcher....

JR
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Nick B
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Re: Basic CPVC launcher - pressure relief question

Post by Nick B »

How old are the kids?

unless you use a compressor, using an average hand pump, the kids will only be able to transfer two thirds or so, of their body weight thru the pump.
Nick and Dad B.