Why no PEX sweep 90 fittings?

[Brian80]

I recently had to take apart some polybutylene piping in my house (ironically, it was actually the soldered joint next it which failed). I noticed their elbow fittings had a gradual sweep like this:



As far as I know, in the PEX world there are 2 options to redirect a pipe in a tight space. It's either a support bracket for large radius corners, or a 90 degree fitting for sharp corners.

PEX and poly-b are very similar in terms of physical characteristics and fittings, so I wonder why we don't see a "sweep 90" fitting for PEX like they had for poly-b. Wouldn't they be better in terms of reducing pressure drops while still working in fairly tight corners?

Just wondering...

 

[Plumber69]

Nope. upsize to 3/4 if you dont think you will get enough volume. Most fixtures like sinks toilets laundry shower hose bibbs you wouldn't notice if you had a few more 90s

 

[Sponsor]

 

[Tuttles Revenge]

It seems logical that the tight bend to those 90s would create more constriction. But maybe the longer radius is more a function of the way copper sweat/solder fittings were made rather than the need of water flow. The predecessor to copper fittings were steel threaded fittings which had no radius and were feeding much higher GPM fixtures. Tees also have no radius to them so their flow would be equally restricted.

 

[Reach4]

Light discussion-- I am not making a point below.

It seems logical that the tight bend to those 90s would create more constriction. But maybe the longer radius is more a function of the way copper sweat/solder fittings were made rather than the need of water flow. The predecessor to copper fittings were steel threaded fittings which had no radius and were feeding much higher GPM fixtures.

Yes, the copper is probably formed from copper pipe. So that could be bent and form. Machining a long term would be hard, but plastic molded pex fittings could have a long sweep if they wanted.

PEX-copper stub-outs have a long sweep.

Tees also have no radius to them so their flow would be equally restricted.

Think of the discussions about what the "bull" (side port) of a tee should be used for to avoid pressure drop problems.

But the tee thing brings up a similar question: why no pex wyes? (rhetorical)

 

[hj]

Cast brass fitting have "square" turns, wrought copper have radiuses/radii.

 

[Fitter30]

Use two 45s for a lower pressure drop

 

[Reach4]

Use two 45s for a lower pressure drop

I suspect that would not help with crimp/clamp PEX.

 

[Tuttles Revenge]

They make PEX 45° ells 1.5" and up I think. Never seen them for smaller diameters, tho my quick google shows sharkbites in 45s

 

[Brian80]

Related to this thread, this company has come out with stainless steel PEX fittings, and their elbow is a long sweep: https://boshart.com/product/pex-90-elbow-2/

I'm not sure where to buy them in Canada though. I'm sure it's quite expensive compared to brass anyway.

 

[Fitter30]

https://www.supplyhouse.com/Holdrit...MIkIq_zu-J9AIV021vBB26UAAGEAQYAiABEgIrTPD_BwE
There are other brands. Need to look into homerun piping for less pressure drop.

 

[Reach4]

https://www.pexsuperstore.com/product-category/pex-fittings/sioux-chief/

https://www.siouxchief.com/products/supply/powerpex-systems/astm-f1807/directionals/elbows/copper
This is for the crimp/clamp type PEX connections.

I did not find a Canadian seller.

 

[Tuttles Revenge]

https://www.supplyhouse.com/Holdrit...MIkIq_zu-J9AIV021vBB26UAAGEAQYAiABEgIrTPD_BwE
There are other brands. Need to look into homerun piping for less pressure drop.

Or just use PEX to its full advantage and make sweeping bends rather than use elbows. Takes a bit of planning and practice to get out of the Copper fitting layout mindset.

 

[Reach4]

Or just use PEX to its full advantage and make sweeping bends rather than use elbows. Takes a bit of planning and practice to get out of the Copper fitting layout mindset.

I have not tried bending 1 inch PEX, but I suspect is is pretty hard. But if you can do it, that is going to be the lowest loss.

Saving that last 3/8 psi of drop doesn't seem that important to me, unless you are the person with the gravity feed system from the tank up the hill or your house is on the hill, and the city water pressure is low.

 

[Fitter30]

Warm pex up with heat gun low heat setting push tubing through the support bracket.

 

[Tuttles Revenge]

I've used electrical conduit for 1" and larger bend supports... usually in groundwork stubbing up into a wall. I have some really nice photos of one of my jobs with elegant water distribution.. Not sure if I have photos of the house I did for a client who was OCD about flow efficiency.. or efficiency of all parts of his home. He had temperature probes all over his home as it was being constructed to graph the energy usage from intitial burn to when the home was fully insulated and constructed. We found the most efficient path for every drain and every bit of tubing reducing every possible unessecary fitting. Even more efficient tub drains! Kinda a PITA but it definately changed the way I look at things to find more efficient routes and reduce costs.

 

[Nebojsa]

I saw Sioux Chief parts in one Home Depot store in Ontario

 

[Gsmith22]

I've used electrical conduit for 1" and larger bend supports... usually in groundwork stubbing up into a wall. I have some really nice photos of one of my jobs with elegant water distribution.. Not sure if I have photos of the house I did for a client who was OCD about flow efficiency.. or efficiency of all parts of his home. He had temperature probes all over his home as it was being constructed to graph the energy usage from intitial burn to when the home was fully insulated and constructed. We found the most efficient path for every drain and every bit of tubing reducing every possible unessecary fitting. Even more efficient tub drains! Kinda a PITA but it definately changed the way I look at things to find more efficient routes and reduce costs.

I would love to see the photos. I tried to make sweeping horizontal and vertical bends (in floors/walls; not coming up out of slab) with 1" uponor pex and gave up switching to the 90 degree plastic angles. heat/no heat didn't seem to matter. that stuff is so resistant to bending and it seems to fall right in the middle between where uponor actively depicts sweeping bends of 1/2 and 3/4; actively depicts use of preformed 90 fittings for 1.5" and above. I couldn't find any recommendation for the 1" and my apparent inability to bend it anywhere close to the radii suggested by their literature left me with a lot more 90 degree fittings than I originally expected.

 

[Plumber69]

We have bad water here. I'm seeing pex fittings fail after 12-15 years. I wonder if stainless pex fittings would be better

 

[wwhitney]

I would love to see the photos.

Here's a photo of 1" (white) PEX bending with a 90 degree bend support and some gentler bends without bend supports.

Cheers, Wayne

 

[Gsmith22]

I was able to do sweeping turns like on the left easily but that 90 degree bend on the right - not sure how you did that without two issues that developed for me. When I tried to do those, I would heat the pipe with a hair dryer in order to press it into the bend support but it would often become out-of-round and flat through the curve which I wasn't at all thrilled with. Plus, I was using plastic bend supports and I was worried about the support digging into the pipe wall. I would think that would be even worse with the metal ones? in your picture you can almost make out a kink in the pipe geometry where it passes through the metal support so I am guessing the situation was similar. I didn't feel comfortable at all with the out of round and pressure on the pipe wall at the supports so I just did the plastic 90 degree fittings.