RCP Pipe Sizes 1

[waterguy926]

I am just making sure that 21" and 27" diameter concrete pipes are manufactured.

 

[leeji]

21" and 27" Pipe (RCP and CMP) is not available (without a special order) in Florida (I'm not sure where you are working though). If you can find it (or get it made), you will probably find it is MUCH more expensive that 24" and 30". If at all possible, stick with the 6" increment pipe (18",24",30" etc.) or your contractor may run into a supply issue when he tries to procure the pipe.

Hope this helps!

Jim Lee, P.E.
City of Tallahassee
Stormwater Division

 

[dicksewerrat]

Go to Hansen Pipe Website. Find the nearest plant to you. they can tell you if the size is available and if the cost is more or less than the 24" and 30"

 

[PECPESC]

Here in Dallas, Texas 21, 27 & 33 are common and very available.

 

[LHA]

Here in PA, I know 21, 27 and 42 are still available in RCP. I do not know if 33 is or not.

In Harrisburg, PA typical cost differentials are as follow (I have done a simple ratio of Q to cost):

RCP Class 3 (typical, mid-weight stuff)
Dia Q,s=.005 $/lf delta Q delta $
15 3.7 11.4
18 4.2 12.0 0.1 0.1
21 4.6 15.6 0.1 0.3
24 5.1 17.7 0.1 0.1
27 5.5 22.0 0.1 0.2
30 5.9 24.0 0.1 0.1
36 6.7 34.5 0.1 0.4
42 7.4 47.0 0.1 0.4
48 8.1 58.5 0.1 0.2
60 9.4 93.5 0.2 0.6

It looks like the biggest rip-off would be increasing from 48" to 60". 21", 27" do not appear to be as inefficient as even 30" to 36", and 42" no more so. This has been an informative exercise for me, as I use 36" RCP quite often.

 

[LHA]

Oops, I messed up. The previous Q was actually v, as I forgot to factor flow area. Looks like my economic analysis changed big-time.

RCP Class 3 (typical-midweight stuff)
Dia "Q,s=.005" $/lf delta Q/delta $
15 4.6 11.4
18 7.4 12.0 12
21 11.2 15.6 2
24 16.0 17.7 3
27 21.9 22.0 2
30 29.0 24.0 4
36 47.1 34.5 1
42 71.1 47.0 1
48 101.6 58.5 2
60 184.3 93.5 1

It appears that the biggest bargain is to increase from 15" to 18", 12:1 Q to cost ratio. Increasing to 21, 27 and 42 inch pipes do not add unacceptably to the cost, relative to their respective next lower size.

 

[0verflow]

Ask Hanson pipe for a catalog. There is a lot of information in there and they gave me mine for free. Tell them you design with RCP and give a work address.