Pex question:whale and seatech compatibility?

[Jsol]

Does anyone know if Whale fittings are compatible with Sea Techs? I'm not talking about the tubing (I'm working with 15mm), but need to use a stackable Tee on an existing Whale Tee fitting. Problem is the Whale version is backordered and the Seatech is available. Any help would be appreciated.

[sailorchic34]

Originally Posted by Jsol

Does anyone know if Whale fittings are compatible with Sea Techs? I'm not talking about the tubing (I'm working with 15mm), but need to use a stackable Tee on an existing Whale Tee fitting. Problem is the Whale version is backordered and the Seatech is available. Any help would be appreciated.

Seatech stackable is 15mm. So should work with the whale tee.

[Jsol]

Originally Posted by sailorchic34

Seatech stackable is 15mm. So should work with the whale tee.

Thanks Sailorchick.

The male side of the seatech fittings look different than the Whale version, so although both 15mm, wasn't sure if it would work...

[sailorchic34]

Originally Posted by Jsol

Thanks Sailorchick.

The male side of the seatech fittings look different than the Whale version, so although both 15mm, wasn't sure if it would work...

That looks to be a depth gauge So you know how far to insert it. Seatech has what looks like a small line. Whale two bumps. Either should work with the other.

Also while standard pex design practice is to use a manifold system with a pipe to each faucet/valve, on a boat/RV the flow demand is low enough that you can use it like a typical plumbing system. That is run the pex around the boat as a single pipe with tees off for separate faucets. The 3.5 to 4 gpm typical pressure water pump does not flow enough water to justify a manifold system on the <55' boat.

[Jsol]

Originally Posted by sailorchic34

That looks to be a depth gauge So you know how far to insert it. Seatech has what looks like a small line. Whale two bumps. Either should work with the other.

Also while standard pex design practice is to use a manifold system with a pipe to each faucet/valve, on a boat/RV the flow demand is low enough that you can use it like a typical plumbing system. That is run the pex around the boat as a single pipe with tees off for separate faucets. The 3.5 to 4 gpm typical pressure water pump does not flow enough water to justify a manifold system on the <55' boat.

Thanks. Yes, it is the two 'bumps' on the Whale that had me wondering. My boat came with drain valves on the pressure side of the system for winterizing and I am just adding a manifold for the non-pressure side so that I can drain via gravity without connecting/disconnecting the pex tubing each season. My understanding is that this can cause leaks over time as the tubing has a potential to get scored. Unfortunately starting to get ready for taking her out for the season
Thanks again...

[Saltyhog]

While on the subject of PEX on a boat.... I'm about to start the replumbing of a sailboat with PEX. Am I better off using 1/2" or 3/8" CTS? The 3/8" looks like it would be a lot easier to bend around, but I'm concerned that the flow won't be enough.

[sailorchic34]

Originally Posted by Saltyhog

While on the subject of PEX on a boat.... I'm about to start the replumbing of a sailboat with PEX. Am I better off using 1/2" or 3/8" CTS? The 3/8" looks like it would be a lot easier to bend around, but I'm concerned that the flow won't be enough.

3/8" CTS (copper tube size) is exactly the same as 15mm pex. It's what I have on my boat. Its more then adequate flow rate wise for a shower or sink faucet.

For a house where you could have a dishwasher, washer and a shower and toilet flushing it would be way to small. But for the average size boat <=50' it would be fine.

[capngeo]

Just keep in mind the inverse square law of moving fluids through a pipe..... doubling the diameter QUADRUPLES the flow at a given pressure. 1/2 will move nearly double that of 3/8. Of course we all know more is not necessarily better in fresh water systems of limited capacity.

Oh, BTW, good info given by a "chick"! My Sexist View LOL!

[Saltyhog]

Originally Posted by sailorchic34

3/8" CTS (copper tube size) is exactly the same as 15mm pex. It's what I have on my boat. Its more then adequate flow rate wise for a shower or sink faucet.

For a house where you could have a dishwasher, washer and a shower and toilet flushing it would be way to small. But for the average size boat <=50' it would be fine.

Thanks! The line in red has me confused. Actually plumbing sizes always confuse me. So from what I understand, 3/8" CTS is actually 1/2" OD. You're saying (and I believe you) that 3/8" CTS is the same as 15 mm. I've seen the PEX tubing speced as both 3/8" and 15mmOD. I guess 15mm PEX has no dimension that is actually 15mm, since:
3/8" == 9.5mm
1/2" == 12.7mm

I accept that non-metric pipe sizes have nothing to do with the actual size. There's likely some historic standard that they're based on. But I'd think that at least the metric sized stuff would be true to size. I think it's all a conspiracy by plumbers to confuse the lay folk so we will pay them their high rates

PS: Nice job on the engine build BTW.

[sailorchic34]

Originally Posted by Saltyhog

Thanks!
I accept that non-metric pipe sizes have nothing to do with the actual size. There's likely some historic standard that they're based on. But I'd think that at least the metric sized stuff would be true to size. I think it's all a conspiracy by plumbers to confuse the lay folk so we will pay them their high rates

PS: Nice job on the engine build BTW.

Good question. The answer is that the plastic pex pipe wall is thicker then the equivalent size copper tube. So PEX with a 3/8" CTS inside is 15 MM outside. Actually the PEX 3/8" is just a bit smaller then the copper size equivalent. But the friction coefficient is better in PEX. So its about the same overall.

capngeo: "the inverse square law of moving fluids through a pipe." Gee Really,I had No Idea.

The 3/8" pipe will move 2.5 - 3 gpm in a small boat no problem. For the typical sailboat in the 30-40 foot range its all you need. Oh I would use 1/2" inside to the pump and maybe 1/2" to the tee to the second head, if there is a second head. But with about 3-4 GPM from the typical 12V pump. 3/8" will be fine.

Actually its the limited water supply that makes 3/8" a better selection. Plus the boats are small enough the friction losses are not really a problem.

FYI: I have 32+ year designing plumbing systems, fire, process, well anything in a pipe, was certified in plumbing engineering 30 years ago and wrote hydraulic analysis software 22 years ago for complex pipe networks (In C++). I've been manager and lead engineer designing plumbing for buildings, where the plumbing construction cost alone was about $40 million.

So I might know a little something about plumbing, despite being blonde. Now can you guess what City that building is in. There really is only one answer in the US anyway. Hint: its NOT in the North East USA.

[minaret]

Ditch those cheap PITA pex fittings and upgrade to Wirsbo tubing with Uponor fittings. So worth it, especially with the cordless tool.

[sailorchic34]

One note: If your using insert fittings with Pex, then use 1/2" minimum. The insert fitting acts as a restriction orifice and will have slightly less flow and somewhat more friction loss then when using fittings that the pex slides into.

So insert fittings, That is fittings that insert into the tubing, go to 1/2" minimum.

For fittings where the tube inserts into the fitting, then 3/8" is OK.

The above applies to boats not homes by the way.

[foggysail]

Originally Posted by sailorchic34

FYI: I have 32+ year designing plumbing systems, fire, process, well anything in a pipe, was certified in plumbing engineering 30 years ago and wrote hydraulic analysis software 22 years ago for complex pipe networks (In C++). I've been manager and lead engineer designing plumbing for buildings, where the plumbing construction cost alone was about $40 million.
.

Chic-- Have you ever thought about trying to get a master plumbing license and starting your own company? Here in MA/RI plumbers live a good life, big bucks and seem to be in constant demand.

I know that many states including NY will allow a PE to take the license exam with some qualifications such as those you possess.

Foggy

[sailorchic34]

Originally Posted by foggysail

Chic-- Have you ever thought about trying to get a master plumbing license and starting your own company? Here in MA/RI plumbers live a good life, big bucks and seem to be in constant demand.

I know that many states including NY will allow a PE to take the license exam with some qualifications such as those you possess.

Foggy

That would be interesting and challenging. I actually have worked for a contractor managed plumbing crews on a highrise or two. Just for fun mind you and experience. I've been a junior partner in an engineering firm in the past, but it was going to be too much boring work. So not into boring. That's why I moved around after leaving senior positions. I've always needed a challenge. Sailings a challenge as you never learn it all.

I think if someone was building a mile high skyscraper, that could be fun. I've done just about everything else.

I'm not really looking to be rich, only happy. I sort of enjoy being a boat bum-ette, more at the moment. No deadlines, no hassles. Just have to find a way that pays me to be one...

[Saltyhog]

Originally Posted by minaret

Ditch those cheap PITA pex fittings and upgrade to Wirsbo tubing with Uponor fittings. So worth it, especially with the cordless tool.

I was planning on using the Seatech push-on fittings per MaineSail. Have you had trouble with those? Was planning this route because of the cost of the tool and ease of assembly and fitting in the tight spaces where boat plumbing lives. If you've had trouble with them though, I'll buy the Wirsbo tool and go with the Uponor fittings. I have 2 boats to re-plumb, so at least the cost of the tool is spread out a bit. Do enough boats and the cost of the Seatech fittings out-paces the cost of the Wirsbo tool (Milwaukee). -Tom