Pipe material for yard/storm drain (PVC or ABS)

[cleverchimp]

I'm doing a yard drain project and the initial planning is to use 4 inch SDR35 pipe but due to the property ground is rather flat, it is hard to get 1/8" drop. My next step is to use smaller pipe, either two of the 2 inch PVC connected using wye or one 3 inch pipe. Unfortunately it is rather difficult to find a store that carry 3 inch PVC pipe, one store wanted $118 for a 10 footer! The big box stores carry only ABS for 3 inch. What would you guys recomend? I never seen anyone using ABS for storm drain, is it because of the cost?

 

[wwhitney]

Presumably the 3" PVC pipe you were quoted is Schedule 40 and rated for pressure applications. For drainage you'd typically use ASTM D2729 3" PVC pipe, it's comparable to 4" SDR35. Commonly called S&D (sewer and drain) pipe.

I infer from your interest in 3" pipe that at the upstream end you have an upper limitation, while at the downstream end you have a lower limitation?

Cheers, Wayne

 

[Sponsor]

 

[cleverchimp]

Presumably the 3" PVC pipe you were quoted is Schedule 40 and rated for pressure applications. For drainage you'd typically use ASTM D2729 3" PVC pipe, it's comparable to 4" SDR35. Commonly called S&D (sewer and drain) pipe.

I infer from your interest in 3" pipe that at the upstream end you have an upper limitation, while at the downstream end you have a lower limitation?

Cheers, Wayne

Yes, it is schedule 40 which is a bit overkill for storm drain. I can get ASTM D2729 3" for about $15 and the store that carries this is a bit further and it is thinner pipe. I thought about $10 more, I can get ABS at the big box stores nearby, it is a thicker pipe.

You are correct. Drilled the hole at the lowest point of the curb and it need to go about roughly 50-60 feet upstream with 1/8" pitch.

 

[Jeff H Young]

go with what you got 1/8 on 4 inch is better than running 60 ft of smaller pipe ( 3 inch ) with .008 inches more fall per ft LOL thats 2 hairs on your head if you ran 2 inch double that to .016 inches per foot in other words a whopping 1 /64th inch .
your talking of gaining 1 inch or less in 60 feet you have 7.5 inches presumeably not much but it is what it is

 

[cleverchimp]

go with what you got 1/8 on 4 inch is better than running 60 ft of smaller pipe ( 3 inch ) with .008 inches more fall per ft LOL thats 2 hairs on your head if you ran 2 inch double that to .016 inches per foot in other words a whopping 1 /64th inch .
your talking of gaining 1 inch or less in 60 feet you have 7.5 inches presumeably not much but it is what it is

Thanks for the insight. That is what I thought too, bigger pipe is better. I wish I can get 1/8 on 4 inch but looks like I'm stuck with lower than 1/8" pitch, worst come worst that I need to snake it once in a while. The curb hole is already at the lowest point and I have to install 3-4 feet of 3 inch from the curb due to some obstacle that cannot be removed then have 3in to 4 in reducer.

Ideally it should be from bigger pipe to smaller pipe but I figure the 3-4 foot to a smaller would be ok.

 

[Jeff H Young]

it does kinda suck ive got kind of a poor mans jetter a pressure washer with hose and attachments for running down pipe . its a gas powered 2700 psi but the gpm is a bit low Ive been blasting it out once a year or so My drains are flexible corugated crap that was basicaly thrown in a trench I dont have very good fall either plus I know there is low spots (belly ) in line Ive replaced some sections

 

[wwhitney]

I have to install 3-4 feet of 3 inch from the curb due to some obstacle that cannot be removed then have 3in to 4 in reducer.

If your outlet is 3" wide, and you use any 4" pipe, use an eccentric reducer where you choke down to 3". Otherwise you'll have 1/2" of water standing in the 4" pipe all the time.

E.g. https://www.fernco.com/dimensional-drawings/1056-43eb-eccentric-series which might require some adapters from S&D to Schedule 40, but for those you could can generally just use a cut off section of s&d hub, as the s&d hub OD is close to the schedule 40 pipe OD.

Cheers, Wayne

 

[Jeff H Young]

If your outlet is 3" wide, and you use any 4" pipe, use an eccentric reducer where you choke down to 3". Otherwise you'll have 1/2" of water standing in the 4" pipe all the time.

E.g. https://www.fernco.com/dimensional-drawings/1056-43eb-eccentric-series which might require some adapters from S&D to Schedule 40, but for those you could can generally just use a cut off section of s&d hub, as the s&d hub OD is close to the schedule 40 pipe OD.

Cheers, Wayne

never seen a eccentric reducer on plumbing or drainage , but used them very often in pipefitting hvac and plant work