jeanette
New Member
Does anyone have any "words of wisdom" for someone looking to have galvanized pipes replaced with plastic PEX pipes?
PEX Re-piping
- Thread starter jeanette
- Start date
Users who are viewing this thread
FullySprinklered
In the Trades
A half-mile walk to the creek with a galvanized bucket would be an improvement over what you have.
Sponsor
Paid Advertisement
Jadnashua
Retired Defense Industry Engineer xxx
PEX is a decent product, and has been used for decades (longer in Europe than in the USA). A couple of design considerations:
- pex has a smaller ID than the same size as copper. That doesn't make much difference except for devices that can use as much flow as possible (tubs, outdoor hose bibs, for example), so to get the equivalent flow, you may need a larger size than if you used copper there. Many things are flow restricted: kitchen faucets, vanity faucets, showerheads. Same guidelines as with copper: you need a large enough trunk before you branch off to individual devices. If you try to just replicate the routing as with copper or galvanized, you will lose many of the benefits of the material. It won't look as neat, but then, most of it ends up behind the wall. The goal should be to use the flexibility of the material to minimize the inline fittings. The stuff bends quite well, and doesn't need fittings to change direction most of the time. While compression valves for say a sink supply will work with pex, many people prefer to use a copper stubout from the pex since it is rigid verses flexible. There are three different manufacturing methods to make pex, -A, -B, and -C. PEX-A is the most flexible, and can be bent into the smallest radius without kinking. It is the only one that supports using an expansion system for the fittings...this means that there is less restriction through each fitting. The fitting is larger, and won't fit into the pipe unless it is expanded with a special tool...then, the tubing collapses on the fitting, locking it in place. The other types will slip into the tubing, meaning they must be smaller, and then you must install a crimp ring to hold it in place. They all work, they just have different features, but like most things, must be installed properly.
Many people tend to use a manifold verses the more traditional trunk and branch system that copper often uses. This has some advantages. The worst thing you can do is treat it like copper and have lots of fittings to make it look neat...a waste of money and producing many more potential sources of leaks or other failure. It takes a different mindset to run pex to its best advantage verses say copper (or in your case, galvanized).
- pex has a smaller ID than the same size as copper. That doesn't make much difference except for devices that can use as much flow as possible (tubs, outdoor hose bibs, for example), so to get the equivalent flow, you may need a larger size than if you used copper there. Many things are flow restricted: kitchen faucets, vanity faucets, showerheads. Same guidelines as with copper: you need a large enough trunk before you branch off to individual devices. If you try to just replicate the routing as with copper or galvanized, you will lose many of the benefits of the material. It won't look as neat, but then, most of it ends up behind the wall. The goal should be to use the flexibility of the material to minimize the inline fittings. The stuff bends quite well, and doesn't need fittings to change direction most of the time. While compression valves for say a sink supply will work with pex, many people prefer to use a copper stubout from the pex since it is rigid verses flexible. There are three different manufacturing methods to make pex, -A, -B, and -C. PEX-A is the most flexible, and can be bent into the smallest radius without kinking. It is the only one that supports using an expansion system for the fittings...this means that there is less restriction through each fitting. The fitting is larger, and won't fit into the pipe unless it is expanded with a special tool...then, the tubing collapses on the fitting, locking it in place. The other types will slip into the tubing, meaning they must be smaller, and then you must install a crimp ring to hold it in place. They all work, they just have different features, but like most things, must be installed properly.
Many people tend to use a manifold verses the more traditional trunk and branch system that copper often uses. This has some advantages. The worst thing you can do is treat it like copper and have lots of fittings to make it look neat...a waste of money and producing many more potential sources of leaks or other failure. It takes a different mindset to run pex to its best advantage verses say copper (or in your case, galvanized).
Last edited by a moderator:
lanachurner
Member
PEX is a great product.
It saves a lot of labor, is cheaper than copper - though the fitting are rather expensive and there's no more worry about burning your customer's house down when you're trying to sweat a copper fitting in a tight place.
It is ugly though. Especially if they use the rolled stuff across a long, exposed run. It droops, etc - not nice straight, tidy runs.
And the thieves don't steal it out of your house when you're gone for the weekend like they will copper.
With all the low flow devices they have now - faucets, showers, toilets, etc I doubt the smaller flow will be an issue at all.
It saves a lot of labor, is cheaper than copper - though the fitting are rather expensive and there's no more worry about burning your customer's house down when you're trying to sweat a copper fitting in a tight place.
It is ugly though. Especially if they use the rolled stuff across a long, exposed run. It droops, etc - not nice straight, tidy runs.
And the thieves don't steal it out of your house when you're gone for the weekend like they will copper.
With all the low flow devices they have now - faucets, showers, toilets, etc I doubt the smaller flow will be an issue at all.
Last edited by a moderator:
Similar threads
