Freshwater System Plumbing

[sailorchic34]

I've used the sharkbite fittings on some of my pex. Sea-tech is good, unless the fittings is under pressure from side loading from the springy pex tubing. I had two sea-tech pex to npt fittings fail. I replaced with brass sharkbite and they were fine.

Years ago using aluminum crimps were the way to go with PB. But different thermal expansion rates between the brass insert fittings and aluminum crimps used at that time, caused the aluminum to loosen and caused tons of leaks.

The Aluminum crimps probably work better in the UK as the hot water pressures in the US are generally higher then UK standards.

PEX is about perfect for boating. Plus 1/2"/15mm will fit inside 1/2" PVC pipe which is what my boat was originally plumbed with.

PEX is pretty hard and hose clamps may not be ideal for clamping. I'm not a fan of insert fittings as pex inside diameter is already about 30% smaller area then equivalent PVC. Added an insert fitting really reduces water flow GPM for a given size.

[FlightPlan]

Any reason not to use the standard Sharkbite brass fittings with stainless crimp rings, either?[/QUOTE]

It is not a marine grade brass. Use the plastic.

[Greenhand]

FoR the record, SeaTech and Whale fitting dare NOT compatible. Of course,you can put anything you want on each end of tubing, but if you are using any stem pieces, like the stackable tee or elbow, the Whale fittings cannot grip the SeaTech stems. The Whale stems have a double groove the makes them fit Whale fittings better. SeaTech fittings are also smaller to fit better in cramped quarters. In general, we got a better seal with SeaTech, but that may have been user error.

[rwidman]

Polybutylene Plumbing and Pipe Replacement-Polybutylene Lawsuit and Class Action Settlement Information

[jeepbluetj]

Originally Posted by rwidman

Polybutylene Plumbing and Pipe Replacement-Polybutylene Lawsuit and Class Action Settlement Information

Don't think anybody's talking about PB. PB is gone gone gone. We're talking about cross-linked polyethylene (PEX).

I replumbed my entire house with the uponor/Propex stuff. Used this tool:
Amazon.com: Milwaukee 2432-22 M12 12-Volt Propex Expansion Tool Kit: Home Improvement

I have a very high degree of confidence I'll never touch it again. I really like the expander type of fitting. They make plastic fittings too, so no brass would be involved. This is what I will use when I replumb my boat. I may have a few press-on fittings for field repairs.

OTOH, sailorchic really really knows her stuff. Personally, I'm not worried about flow rate because, well, it's a boat, the water's coming from a tank, and I get great flow with 1/2" uponor fittings in my house. But she may have a very good point, I have NOT used it on the boat.

[sailorchic34]

Originally Posted by jeepbluetj

Don't think anybody's talking about PB. PB is gone gone gone. We're talking about cross-linked polyethylene (PEX).

I replumbed my entire house with the uponor/Propex stuff. Used this tool:
Amazon.com: Milwaukee 2432-22 M12 12-Volt Propex Expansion Tool Kit: Home Improvement

I have a very high degree of confidence I'll never touch it again. I really like the expander type of fitting. They make plastic fittings too, so no brass would be involved. This is what I will use when I replumb my boat. I may have a few press-on fittings for field repairs.

OTOH, sailorchic really really knows her stuff. Personally, I'm not worried about flow rate because, well, it's a boat, the water's coming from a tank, and I get great flow with 1/2" uponor fittings in my house. But she may have a very good point, I have NOT used it on the boat.

The uponor fittings would probably be ok as your expanding the pex so the fittings inside diameter is very close to line size. Of course there may be other issues with expanding the pex plastic, but it looks like an extrusion and PEX is rather forgiving that way.

The issue would be with un-expanded ends with a insert barb fitting. That is one reason, many homes are done with a manifold with separate runs to each fixture. The insert fitting acts as a restriction orifice. Why I like the seatech / sharkbite type fittings as they give full line size, or very close to it. The Uponor system would be fine, I'm thinking.

Oh, on the sharkbite being brass. Dezincifacation is far less a problem with fresh water. Salt water, it's a no-no to use brass. Fresh water. generally not a problem. I would expect oh 15-20 year life or longer with a sharkbite fitting.

Remember plastic is not perfect either as it can be effected by UV and heat where it can become brittle with age.. PEX though is just about perfect for boat fresh water systems. Far better then PVC or vinyl.

[FlightPlan]

Originally Posted by jeepbluetj

Don't think anybody's talking about PB. PB is gone gone gone. We're talking about cross-linked polyethylene (PEX).

I replumbed my entire house with the uponor/Propex stuff. Used this tool:
Amazon.com: Milwaukee 2432-22 M12 12-Volt Propex Expansion Tool Kit: Home Improvement

I have a very high degree of confidence I'll never touch it again. I really like the expander type of fitting. They make plastic fittings too, so no brass would be involved. This is what I will use when I replumb my boat. I may have a few press-on fittings for field repairs.

OTOH, sailorchic really really knows her stuff. Personally, I'm not worried about flow rate because, well, it's a boat, the water's coming from a tank, and I get great flow with 1/2" uponor fittings in my house. But she may have a very good point, I have NOT used it on the boat.

I agree. Most people don't realize that most plumbing breaks down to 3/8 inch supplies at the stop under the sink. Also people not properly selecting the right fittings to the pipe they buy are asking for trouble if they hook up to the dock water directly. Usually the pressure is higher on the dock than the pump in the boat. Just a caution. I have plumbed with Uponor Pex expanded fittings. It is a slick system having the manifolds where you can check them. There are no bands to deal with and water & seawater do not damage the system. One problem I don't have to look back on. Another feature is that it won't rupture in freezing temperatures, it expands and contracts molecularly like Chinese hand cuffs. Good stuff

[sailorchic34]

Originally Posted by FlightPlan

Another feature is that it won't rupture in freezing temperatures, it expands and contracts molecularly like Chinese hand cuffs. Good stuff

I should note that the freeze thawing of the water in the pex, expands and contracts the pex. There is some loss of strength in pex due to that stretching. It's not a lot, but it does effect the materials strength, though to a far lesser degree the other plastics or metal.

I would not rely on PEX to remain leak proof through many winters of cyclic freezing. Better to winterize the water system.

[jeepbluetj]

Originally Posted by sailorchic34

The uponor fittings would probably be ok as your expanding the pex so the fittings inside diameter is very close to line size. Of course there may be other issues with expanding the pex plastic, but it looks like an extrusion and PEX is rather forgiving that way.

They're a bit smaller ID, but it's not as small as the other styles of crimp style fittings.

Using the Uponor stuff is a joy and it's super fast. Stick a ring on the end of the tubing (it's a pex ring, not metal) jam in the expander, pull the trigger, clack clack clack, then stick the fitting in there. 30 seconds later it's done. Amazingly tight clamping force. This is da good stuff.

I can see where the push on fittings are real nice for field replacements on a boat.

[Suijin]

Can anyone tell me with authority whether the PEX tubing sold by Whale and Sea Tech are interchangeable with the PEX tubing you buy at HD/Lowes? What info I can find seems to indicated that the diameters are slightly different. The Whale PEX tubing is like .70/foot, while the HD PEX tubing is .28/foot.

Sailorchic, thanks for the heads up about the side loading vulnerability. I would not have considered that and I think given the route much of this plumbing is taking that it will be an issue if I want minimal fixtures to make turns during the runs. I'll give it some thought.

Thanks.

[jeepbluetj]

All my knowledge is residential. In the US there are pex A,B, and C. HD sells c. The A grade is needed for the uponer fittings. If the whale or seatech stuff is close in O.D. youll be fine. Do a test.

[rwidman]

Originally Posted by jeepbluetj

Don't think anybody's talking about PB. PB is gone gone gone. We're talking about cross-linked polyethylene (PEX).
......... .

Somebody did mention PB (post #16). He said he had a lot of it left over from building houses and wondered if it would be suitable for a boat. I suggested that there had been problems with it and it was no longer used. He disputed that statement so I posted the link.

I am on top of this thread and in fact, did suggest PEX.

[lateral]

Actually, that was tongue in cheek about the tradesmen.
I dont know whether the pb you are talking about is the same as our buteline. Ours had
plastic tail inside the fitting with a Al crimp. Non detachable unlike dux.
I am not a plumber but seem to end up doing some anyway?

Thanks for the link anyway. I will attend to it after coming to grips with my refrigeration, cooling syst, electrics, refurbing mast, building a dog run for the admiral.
Dog yet to be chosen!!

[FlightPlan]

I would not rely on PEX to remain leak proof through many winters of cyclic freezing. Better to winterize the water system.[/QUOTE]

I do rely on PEX (Wirsbo), in my driveway. Eighteen years ago, I removed and replaced my driveway which has a 25 degree slope and we installed 5 thousand feet of PEX in the concrete pour. No leaks. Average annual temperature swing in Tulsa is 8 to 108 degrees. I'll grant you that it is an open system to the swimming pool, but the bottom of the loops are 40 feet below the supply level. I installed per manufacturers recommendation and made sure that none of the piping is exposed to UV. That is the killer to PEX. Some surplus tubing was stored on the West side of my house and after a year it was brittle as glass.

The Uponor tubing installed with the expansion tool has memory because of the pipe structure. Ask anyone who has waited too long to fit the pipe to the fitting. I don't recommend Home Depot or their sales staff to give you the information needed to make a serious decision. Go to a plumbing supply house like Ferguson, Hughes or Hojoca where the staff has been trained. You will be directed to a system like Uponor or Viega which are highly recommended and have web pages. You won't spend much more there and if you have your layout drawing, they will sell you the fittings you need.

One trick to avoid expanding the tube and fitting hook up in tight places is to run you line loosely pull up the manifold do your fit, and then when all is tied together, fasten the tube down. The best way to use PEX is to home run to your fixture from a source manifold where you have no fittings in between. Not always possible I know but it is the best way. AND don't kink it.

But what do I know, I was a lowly licensed mechanical and plumbing contractor for thirty five short years.

[Matt Johnson]

Originally Posted by Suijin

Can anyone tell me with authority whether the PEX tubing sold by Whale and Sea Tech are interchangeable with the PEX tubing you buy at HD/Lowes? What info I can find seems to indicated that the diameters are slightly different. The Whale PEX tubing is like .70/foot, while the HD PEX tubing is .28/foot.

Sailorchic, thanks for the heads up about the side loading vulnerability. I would not have considered that and I think given the route much of this plumbing is taking that it will be an issue if I want minimal fixtures to make turns during the runs. I'll give it some thought.

Thanks.

I would like to know this too. Whale has a pex fitting that attaches directly to their foot pumps and eliminates having to use a length of vinyl hose.

I would just use whales hoses and fittings, but it seems that it may be more difficult to get a fitting when out cruising...unless in an area with metric system.

Matt