Water line fittings 1

[bank]

Simple question: Are wye fittings ever used on water mains? I'm used to seeing tees where a water line connects with another one, but I have a set of drawings in front of me on which the engineer is showing a lot of, what I consider unnecessary, wyes. The water mains are primarily 8" and 12".

 

[dicksewerrat]

Doesn't make much sense unless they are there to just use up some extra stuff laying around.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[cvg]

unless it is a gravity line, no need foor wyes

 

[bimr]

Agree with the previous comments

 

[fel3]

Wyes are certainly available and can be used, but I've never seen one in a water distrubution system. A tee + 45° ELL is standard.

The only time I've see a wye on a water line was on a wall-mounted 8" pipe in a wastewater treatement plant. The wye was used there because of space constraints.

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"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[rconner]

Over the years I guess I've seen wyes occasionally specified in water systems. However, wyes have traditionally been "special" items (not shown/detailed in standards like more common tees and bends etc.), and therefore they are of basically/mostly proprietary designs. Due to the very sharp/acute turn where the branch meets the body, they are also a fitting that concentrates stress more than others, and at least in larger sizes must be reinforced to dependably handle high pressures. All of these factors also play into generally less availability and higher costs of/for wye fittings.

 

[jgailla]

I've never seen or designed a wye on a potable water system, but I have less than ten years experience in potable water and only in the Southeast U.S.

 

[CPENG78]

I have seen a few times on drawings from other engineers. In those few instances I have made it a point to have them removed. As many have said here, they do not make sense. In terms of hydraulics, and depending on overall system configuration, the minor losses through that fitting would be greater than a 90 degree elbow as water would attempt to turn the corner. Even more for larger size pipes as original posts states.

 

[Alula]

Most of the time the master plan f towns is not suitable to use wyes but, if it is why not? They are better in hydraulics than tee and 45deg. elbow that's why they are used at suction or delivery pipes of pump

 

[coloeng]

Alula, most water distribution systems are looped and the flow of the water can go in any direction. Imagine if you have a wye in a line that is going up and the wye is going to the right, you will have less headloss than you would for a standard tee if the water is flowing that direction. But, if the water is flowing down and trying to go left into the wye, you will have much greater headloss than a tee. Because you don't know which direction the water will be flowing at any given time, overall you would have less headloss with a tee than you do a wye.

Hope this makes sense.

 

[77JQX]

We would avoid wyes because we want to have off-the-shelf components in case we need to replace them in an emergency. Our local distributor will have tees and 45s in stock, but won't have wyes. Replacing a wye with a tee and 45 isn't as simple once the connecting pipe is buried.

 

[ElSid1]

unless it is a gravity line, no need for wyes

Agree. They are used in HVAC and plumbing ALL the time. Plumbing somewhat invalidated the "off the shelf" issue noted above (you may have an issue with certain materials being off the shelf, but they do exist). For pumping systems, not used so much. I have seen it, but the plant later reversed the flow in the lines due to re-configuration

But, if the water is flowing down and trying to go left into the wye,

.