PVC SEWER SPECS 1

[WILDWINGS27]

FOR A NORMAL SANITARY SEWER, I NORMALLY SPEC. A PVC PIPE ACCORDING TO ASTM D-3034 WITH ASTM D-3212 JOINTS. HOWEVER, WHEN CLOSE TO A WATER MAIN, I HAVE BEEN TOLD THAT I CAN USE THE SPEC ASTM D-2241 WITH ASTM D-3139 JOINTS FOR LOW PRESSURE APPLICATIONS. HOWEVER,WHEN I LOOK AT THE ASTM SPEC.,IT DOES NOT SAY WHAT THE PIPE ACTUALLY IS, JUST THE TESTING METHODS. I KNOW THAT USUALLY SANITARY SEWER IS SDR 26. BUT WHEN I SPECIFY THE LOW PRESSURE PIPE, WHAT IS THAT? IS IT SDR 23.5?
I GUESS I AM LOOKING FOR SOME CLARITY WHEN I TELL CONTRACTORS WHAT TO INSTALL. WHAT IS THE DIFFERENCE BETWEEN STANDARD PVC SANITARY SEWER FROM LOW PRESSURE SANITARY SEWER, TO FULL WATER MAIN PVC? IS IT JUST A DIFFERENCE IN THE THICKNESS (SDR)? OR IS IT SOMETHING MORE?

 

[zabrab]

From your question it sounds as if the sewer will be within the normal and customary water/sewer isolation distance established by the AHJ (authority having jurisdiction). If this cannot be avoided, there usually is a provision to construct the sewer with upgraded (pressure rated) pipe to lessen the chances of exfiltration and potential contamination to the water system.

WHAT IS THE DIFFERENCE BETWEEN STANDARD PVC SANITARY SEWER FROM LOW PRESSURE SANITARY SEWER?
I can't give you specifics on what are the actual differenes beween the ASTM specs, but ASTM D-3034 pipe is intended for gravity sewer applications (it is not pressure rated). ASTM D-2241 pipe is pressure rated. ASTM D-2241 pipe could be used for force mains or water mains.the differences are probably related to the quality of the PVC itself and design differences in the corresponding joints needed to meet the pressure ratings.


TO FULL WATER MAIN PVC?
By full water main PVC, I assume you mean AWWA C900. Compared to ASTM D-2241 pipe, C900 pipe has a higher factor of safety (2.5 to 2.0) for a given pressure rating/class and C900 pipe has an allowance for surges where ASTM D-2241 pipe does not.

IS IT JUST A DIFFERENCE IN THE THICKNESS (SDR)? OR IS IT SOMETHING MORE?
SDR is SDR is SDR. It's just the ratio of the pipe OD to wall thickness. A C900 pipe, (pressure class 150) has a DR of 18 whereas an ASTM D-2241 (pressure rating 160) has a DR of 26. For given pressure ratings and pressure classes, there are differences in thicknesses depending on the requirements of the spec, but for a given SDR (or DR) the thicknesses will be the same regardless of the spec.

I'm rambling on to much and not really going anywhere so let me get a little more pointed.

If you want to find out about the various PVC pipe specs, get a few people in your office together, call the local PVC pipe rep and ask for a lunchtime presentation about PVC pipe. Also see if you can get him to pony up a Uni-bell handbook for the office.

As for what to tell the contractors and/or what ot put on your plans, find out what SDR under ASTM D-2241 the AHJ requires and call out that. There are only 2 SDRs that are common between ASTM D-2241 and ASTM D-3034, SDR 41 (which no one around me uses for gravity or pressure service) and SDR 26 (which is in common use around me for both gravity or pressure service).

A word to the wise: If you use ASTM D-2241 SDR 26 for your gravity application, make sure your plans clearly call it out as ASTM D-2241 pressure pipe, check the product submittal carefully, and, perhaps most importantly, make sure your constuction observer checks the actual pipe in the field to the approved submittal.

 

[WILDWINGS27]

THANKS FOR THE HELP