"Sharkbites fail"

[daddo]

That's backwards. Liquids under pressure are much more dangerous than gasses. Much more mass involved with liquids than gasses. Think pressure washer, water jet cutter. Gasses don't have the energy that liquids do. Also a break in a 100 psi line of air or a hydraulic line that hydraulic line is allot more dangerous than air is.

 Air stores more energy by volume than liquid.
 When 100 cubic feet of 100 psi compressed air is released, it must release all of the air. When 100 cubit feet of 100 psi of water is released (which doesn't compress), the only release is a small amount of the water which is released only because of the stored energy expansion of said pipe or trapped air.

 This is why we use compressed air to move stored liquids in spray guns, tank sprayers, aerosol cans and so on. You'll notice the cans are never full of liquid. Fill your sprayer to the very top with liquid and see if you can pump it up with enough air to spray with but a short burst.

 Now if you have a large piped water supply or pump @ 100 psi, you have constant energy and that is a little different, but we are talking water/air supply/storage.

[crokett™]

sharkbites are a temporary fitting IMHO

Do you have personal experience with Sharkbites?  A decade ago I was moving our washer to the basement.  We were converting the laundry room to a bath.  I was at the plumbing supply place getting a pump to plumb the washer drain to so it could pump up and across the basement to the septic.  I asked the guy about converting copper to Pex.  he handed me a display of pipes connected with Shark Bite - they were newish then.   I couldn't pull it apart.  I watched him fill it  with water and watched the pressure gauge get to 60 psi and hold.   I used them to plumb the washer supply because they're reversible and we were planning to move the washer.   I had sharkbites to convert the existing copper to Pex, then a few Shark bite elbows, some shark bite shut off valves and the the threaded connections to mate to the washer hoses.  I used them because the washer location was 'temporary'.  that was 10 years ago, that plumbing is still there and still being used.   

They're expensive, but in terms of time saved and skill level and tooling required, much cheaper than sweated or Pex fittings.

[iamrfixit1966]

That's backwards. Liquids under pressure are much more dangerous than gasses. Much more mass involved with liquids than gasses. Think pressure washer, water jet cutter. Gasses don't have the energy that liquids do. Also a break in a 100 psi line of air or a hydraulic line that hydraulic line is allot more dangerous than air is.

No, that's not correct. High pressure pinhole leaks in fluid lines can be dangerous but they are nothing compared to a catastrophic failure of a pressurized line containing any type of compressed air or other gas. I work in industrial maintenance and routinely test pipes, vessels, tanks and boilers for mechanical integrity after welding procedures are complete. Hydrostatic testing is MUCH safer and the industry standard final test to verify the integrity of construction or repairs. Liquids don't compress, so while they can be pressurized they have much lower stored energy.




Sharkbites seal to the pipe using an O-ring and O-rings fail over time. A member on another forum posted that somewhere in the fine print he found that they had a life expectancy of approx 15 years. Plumbing systems can spend decades in a home and the numerous fittings buried inside walls, floors and ceilings offer potential for failure and damage. I certainly would not trust an O-ring to do the job. These fittings haven't been around long enough to justify any claim that they are a permanent solution. They are slick for a temporary installation or an emergency repair but I'll never put one behind a wall. The cost to go in and open walls and ceilings and repair the damage when these start to fail would be enormous. There is a reason most pro's don't use these things except for very select applications.

I've seen them pop off when they didn't grip the pipe correctly and I've seen them begin leaking after piping was disturbed during some other work. Rubber ages and becomes less resilient and that can be accelerated with heat and exposure to many things like cleaners, vapors or even sunlight. There is no reason to use them for an entire plumbing project, there are better ways. Additionally, they are very expensive. I can install several crimp, clinch or expansion fittings for the price of one sharkbite. The tools to make these type connections are not expensive, most can be had for $50. Any cost for the tools is quickly offset by the high cost of the sharkbite fittings. It probably takes about the same skill to operate most of these tools as it does to ensure a sharkbite is properly installed. The tools last almost forever so you'll have it a long time or it can even be resold to recover most of the cost if you choose. These type of connections offer a more mechanical connection that is far more secure and has been proven over the test of time on numerous types of material.

[pprobus]

 Air stores more energy by volume than liquid.
 When 100 cubic feet of 100 psi compressed air is released, it must release all of the air. When 100 cubit feet of 100 psi of water is released (which doesn't compress), the only release is a small amount of the water which is released only because of the stored energy expansion of said pipe or trapped air.

 This is why we use compressed air to move stored liquids in spray guns, tank sprayers, aerosol cans and so on. You'll notice the cans are never full of liquid. Fill your sprayer to the very top with liquid and see if you can pump it up with enough air to spray with but a short burst.

 Now if you have a large piped water supply or pump @ 100 psi, you have constant energy and that is a little different, but we are talking water/air supply/storage.

Yes, Daddo's correct.  Think about compressed air like a spring.  How many springs have killed people because they did not appreciate the stored energy in the spring and remove a bolt or nut that was holding back that energy?  This is why there are special tools for removing the springs from struts, which have been known to kill unsuspecting car mechanics and I have heard of stories of folks working on garage door openers who have either been killed or seriously injured from those springs.  You have to slowly remove the pressure from a spring and the same with compressed air.  I have never heard of any liquid system turning failed fittings into projectiles, even high temperature hot water which is water at high temperatures (300 F +) and at high pressures, while I have heard plenty of stories of compressed air and steam systems turning failed fittings into projectiles.  Specifically, I was told by folks who witnessed the system failures of a high pressure steam heating system put into a building where they used brass ball valves that ended up failing and shooting the ball part of the valves out through the broken valve bodies.

I understand my risks and I do appreciate the risks and have taken all the steps I could think of to mitigate them in my compressed air system where I am using shark bite fittings.