Tires are flexible and they give. When you put air into them, they swell up as the pressure builds. The swelling also slows down the build up of pressure.
PVC is not flexible. Maybe using an air hose from a filling station is not such a good idea. The results could be explosive if the pressure builds up too fast. I think I'll use a bicycle pump to put air into my Playsport Pressure Tester. I should be able to get to 3 ATM and not kill myself with PVC shrapnel.
Good idea. Compressed air explosions are no joke. I bet that the valve stem would make a dandy bullet, too, so it would probably be a good idea to have it aimed in a safe direction while you pump it.
ReplyDeleteJust a couple of weeks ago, I made the mistake of using an air compressor to inflate my bike tires instead of a hand pump. The front tire didn't explode right away, it waited until I was riding at speed down the long, steep hill in front of the house. Tore out the side of the rim when it blew, too. Luckily, I didn't lose control of the bike and didn't fall over, but still it was pretty exciting. And it mainly happened because the compressor inflated the tire so fast that it overpressurized.
Good points, Tim. Since the Pressure Tester has such small volume, it should only take a few pumps to double or triple the pressure.
ReplyDeleteAddendum: Added pressure per pump can be calculated by volume, too.
ReplyDeleteYes, this is very good thinking. You should have some sort of pressure release value otherwise. Like a pressure cooker.
ReplyDeleteKelly, that's a good point. Using a bicycle pump will eliminate the need for a pressure relief valve.
ReplyDeleteBlack pipe is usually ABS not PVC Did you check this? You need to use the correct cement. From the specs on PVC and ABS pipe:
ReplyDeleteAll pipe and fittings to be produced by a single manufacturer and to be installed in accordance with manufacturer’s recommendations and local code requirements. WARNING! Never test with or transport/store compressed air or gas in PVC pipe or fittings. Solvent cements shall conform to ASTM D 2564. Primer shall conform to ASTM F 656. The system to be manufactured by Charlotte Pipe and Foundry Co. and is intended for non-pressure drainage applications where the temperature will not exceed 140°F.
link here: http://www.charlottepipe.com/Documents/Specs/Plastic_Pipe_Fittings_Drainage-SF.pdf
Be careful!
Please be careful. You could be making a grenade. Specs on pvc/abs pipe:
ReplyDeletehttp://www.charlottepipe.com/Documents/Specs/Plastic_Pipe_Fittings_Drainage-SF.pdf
From this spec:
WARNING! Never test with or transport/store compressed air or gas in ABS pipe or fittings. Solvent cement shall conform to ASTM D 2235. The system to be manufactured by Charlotte Pipe and Foundry Co. and is intended for non-pressure drainage applications where the temperature will not exceed 160°F. Same for PVC.
Oh yeah, black pipe is usually ABS not PVC.
Have you tried your pressure test yet?
ReplyDeleteI've completed construction, but haven't tested it yet.
ReplyDelete