GRP Pipe Thickness

[Maher K]

Hello,

While looking into the GRP pipe catalogue, I found out that the thickness of the pipe decreases with the increase of the pipe class especially when it increases from PN10 and higher. This is totally different to what we used to know for ductile iron pipes.

Any idea behind this?

 

[LittleInch]

Can you past a link or the catalogue.

Doesn't seem right.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Maher K]

Attached the a copy of the catalogue.

 

[LittleInch]

Hmmm. Interesting.

I looked at their brochure.

I'm not sure but it may be that they add more steel to the higher pressure pipes which results in thinner wall.

Difficult to tell.

Have you asked them?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Maher K]

Yeah, I sent them an email. Will update you o

 

[saikee119]

This is just my interpretation.

I believe the pipe in question is a standard product which can be used in different pressure conditions. For example if one buys a 400mm diameter GRP pipe and subject it to 3 bar the relevant thickness is 7.84mm. However if the same pipe is used in a 32 bar condition this pipe should be considered having 7.2mm thickness. All GRP pipe has a resin rich layer internally and externally and the manufacturer arrangement can vary slightly for differet pressures and different purposes.

My experience on GRP pipes is the selection is based on the stiffness class SN as nearly all my projects the pipes would be buried. I dealt with large diameters mainly and I know for a fact most pipe suppliers would recommend a thinner pipe, with less thickness and so less material, to be burried with a highest possible grade of backfill. In other word the offer pipe has a lowest possible stiffness class and too flexible but it can do the job if I surround it with rock that can hold it in shape when under load. The AWWA design codes do allow sucjh arrangements.

If a pipe is above ground where the load is mainly internal then you can have it used on higher pressures and lower stiffness classes.