Water heater supply line

Question

what's the correct way to hook up either a mesh flex-line, or a copper supply line with fittings? apparently, i crimped the old mesh line as i was tightening it up and want to make certain i do it right next time. it's my cousins house and his water heater, (at the supply line), was leaking, but he needs hot water when he gets out. thank you.

Answer 1

Any time you're dealing with flex lines you need to make sure you don't kink them (obviously), and so you'll want to make sure you have the right length line so you don't have too much, or not enough flex.  After you've got your new flex line, it's a good idea to lubricate the compression or union nut (depending on fitting type), so that it will slide easily on the compression or union fitting.  Graphite in isopropal alcohol works very well for this, and is non toxic.  When lubricating with graphite it's important to let it dry for 3-5 min, before using it.  for union type fittings, you should be able to slide the nut back, so that you can actually lubricate both surfaces and get a better run in when you actually assemble the joint.  Powdered graphite also works well with compression fittings that you can't slide apart.  It's also a good idea to lubricate the threads to reduce running torque, and to prevent seizing if you ever have to install a new water heater, or disconnect it for repairs.  When actually assembling the joint, you'll want to hold the flex hose firmly in one hand while finger tightening the nut as much as possible.  After the joint is finger tight, you'll want to use a wrench to get another 1/4 turn (compression fittings) or wrench tight with union fittings (for proper o-ring compression).  over tightening any compression fitting can cause it to leak due to metal distortion.  If you're using a union type fitting, you'll want to use some silicone on the o-ring to make assembly more flawless.  if your unit is pipe thread, you can use teflon tape, but it's really not needed.  Most copper lines are soldered.  if you're up to the challenge you'll need to bend tubing with a bender (so tubing isn't kinked, and use silver solder or tin/silver solder.  Solid core works better for plumbing, using brush on flux instead of flux core solder.  when soldering copper based pipes evenly heat the fitting untill a blue flame starts to turn a light green color, and then melt solder right along the joint.  It can take a little practice so if you haven't soldered or "sweated" copper pipe/tubing, you may want to get a few extra fittings to practice a little before you actually go to work on plumbing.  After you solder a joint you'll want to drain, refill, re-drain, and refill the water heater again to flush the new section of pipe, and get the flux out of the line before you actually go to use the water.  

Answer 2

Use a pair of channel lock pliers to hold the mesh and keep it from twisting and kinking while you are tightening the fitting. You won't have to squeeze it to much, just enough to keep it from twisting.