Solvent Cement Joints PVC Sewers 1

[allie075]

Hi everyone,

I am based in the Caribbean. Can anyone tell me why ASTM D3034 and ASTM D2855 would not be applicable for this region? There are no local sewer jointing standards but the local Approval Agency seems to be against solvent joints. Is there substantial evidence that these joints do not work and if so, why hasn't ASTM withdrawn the standards for solvent joints?

Thanks,
Allie

 

[bimr]

Underground pipe typically uses a "push-on" gasket style of pipe that compresses a gasket into a space formed between the two adjoining pieces. Push-on joints are available on most types of pipe. Under buried conditions, gasket-joint pipes allow for lateral movement due to soil shifting as well as expansion/contraction due to temperature differentials.

Push-on joints are considered to be flexible joints. Solvent welded pipe joints are considered to be rigid, not flexible and will tend to break with lateral soil movement.

That is why water and sewer pipe are not solvent welded.

 

[stanier]

BIMR There is nothing wrong with solvent welded joints. In fact they outperform rubber ring joints. RRjs are subject to root ingress, deflection due to ground movements and leakage due to poor installation.

As for why ASTM do not cover Solvent cemented joints i csannot answer. But in other parts of the world this type of joint is OK.

PVC-U uses a solvent cement joint rahter than a solvent welded joint. The latter is used in ABS piping.

 

[bimr]

I did not post that there is anything wrong with solvent welded joints.

What I posted is that underground water and sewer piping typically use flexible jointed piping.

 

[rconner]

A similar subject was discussed some time ago at

http://www.eng-tips.com/viewthread.cfm?qid=217072.

[Maybe only other thing I could add may be that a standard rubber ring joint is normally "unrestrained", though a solvent weld joint is also supposed to offer restraint.]

 

[Hoagie]

Some of the Carribean islands have very corrosive ('agressive') soils...also, some of the islands are located in highly active, hazardous seismic zones.

When I lived in the Carribean in the 90s, the (design)attitude was to allow for flexibility and..."let it move where it wants to move.."

For sewers, I'd spec a push-on type joint with a corrosion resistient gasket (Nitrile, Fluorocarbon, etc) in lieu of a rigidly glued joint.

H.

 

[stanier]

If you read the results of the Kobe earthquake disaster you will fond that rubber ring joints were found to be the cause of many leaks in the sewer system. No the authoirities no lionger want to use this type of joint and have movbed to other solutions.

 

[rconner]

[I agree with the vulnerability of pvc rubber ring joints in seismic events, see however also comment re “solvent weld pvc” and seismic performance in slide on page 4 entitled “House Services” at

http://www.pnws-awwa.org/Files/4-Ballantyne - Pipelines.pdf

]

 

[allie075]

Hey guys,

Thanks alot for your responses. Synopsis: solvent weld is the worst type of joint to use in sewers within earthquake zones. Gasket joints aren't too good either but perform better than solvent weld joints except in extreme earthquake events. Cool.

Allie.