Pipe schedule/type 1

[DesmoFan]

I am in the planning stage to replace part of an underground water system that operates at 180 psia. The drawings of the system are dated from late 1950s. The drawing indicates one of the pipes is 16" CW-175, and that it is cement-mortar lined. I measured the outside diameter of the pipe (twice) and it measures 14.75 in. Not sure what the CW or the 175 means. Anyone familiar with this type of pipe, it does not seem to match any pipe schedules I know of.

(There is also a 30",20",14", and 12", all say CW-175)

 

[StevenHPerry]

Sounds like a piping class / spec.

CW = Circulating Water?
175 = 175psig working pressure? (you said 180psia, so 175psig fits)

Why the OD is 14.75 on a 16" nominal line is another matter. That doesn't fit IPS or DIPS at 14".

- Steve Perry

http://www.linkedin.com/in/stevenhperry

This post is designed to provide accurate and authoritative information in regard to the subject matter covered. It is offered with the understanding that the author is not engaged in rendering engineering or other professional service. If you need help, get help, and PAY FOR IT.

 

[rconner]

I guess could add at least guesses Cooling Water, Chilled Water, Commercial Wrought, Crane Welded, ???(Don’t you just love acronyms that are not defined in documents on which they appear?)

As to weird O.D. size you found, ‘bout only thing I can even think of is a mis-marked 14” steel line that was rolled to a special little larger O.D. size size so as to end up with ‘bout a nominal 14” lined bore with wall and lining thicknesses considered, though I've not even heard of that being done on this small of pipe (at least one of the pipe sizes you believe you have somewhere is 14”!)

 

[ione]

C.W. could stand for continouos welding. Quite a common practice to use continuous welding steel pipe with cement mortar lining for big water pipe applications.
I do not have any idea about the meaning of the number 175 and odd sizes.

 

[SNORGY]

Could the CW-175 simply refer to the governing Client / Owner piping specification that was in effect at the time?

Regards,

SNORGY.

 

[DesmoFan]

Thanks to all that have responded, I decided to measure the other pipes and in doing so discovered the tape measure I grabbed out of the shop had the beginning shortened. I got another tape and the diameters match current piping specs (16" measures 15.98") so the only mystery that remains is the CW-175 designation. I agree the 175 could be a pressure designation, just trying to figure out what that means in regards to wall thickness.

 

[TD2K]

Would an ultrasound tell you the thickness of the pipe if it was cement lined? UT is used all the time to inspect existing piping for corrosion and erosion but I don't know if the cement lining would throw it off.

 

[Duwe6]

UT-thickness will work fine. The interface between the steel and the cement will give a fairly strong return signal.

 

[XL83NL]

In view of ione reply fow what CW stands for;
I have a client spec that lists "ERW API 5LB C&W". Anyone has an idea what C&W standa for?
The welding is already defined by ERW, its plain API 5L grade B pipe, so I was under the impression C&W is not some sort of abbreviation for welding or whatever.

 

[pennpiper]

C & W = Coat and Wrap (Coat with one or two layers of hot Bitumen Tar, wrap with Tar Paper then coat again with hot Bitumen Tar.

 

[11echo]

Agree with pennpiper's assessment of CW! ...Coat and Wrap!

 

[rmw]

I have been the victim of a measuring tape with the same problem. You gave me quite the laugh. The guys in the shop knew about it and always compensated for it. But did they tell me.......


rmw

 

[rconner]

If the pipe is "coated and wrapped", you may wish to check the foreword to AWWA C203 with regard to potential materials used (if you are working with this old pipe).

 

[XL83NL]

Thanks all, but (luckily) dont need the C&W pipe anymore ..