Replace asbestos cement water pipe, help.

[Cantick]

We have a private 1500 meter water pipe feeding our rural property. The first section 300m is laid in 32mm blue plastic pipe and the remaining 1200m is 2” asbestos cement pipe (75 years old). The property is about 10 meters above the start of the run. Would replacing to whole run in 32mm pipe have a detrimental effect to the pressure and flow feeding the property? What is the most cost effective solution? Thanks in advance.

[Conor]

I'd avoid going near the AC pipe unless it's leaking badly. It's not doing any harm. We've thousands of miles of AC pipe in this country.

 

A 2" AC pipe will have more than three times the capacity of a 32mm mdpe pipe. If you have current flow/pressure issues, they will get worse. You'd want to replace with 50mm or 63mm mdpe.

 

If you do replace the ac main, leave it buried and lay the new pipe in a new trench. Either that or pipe burst. Either way, it'll be a big chunk of money.

[joe90]

“If it ain’t broke, don’t mend it” Is one of my motto,s. If you do replace it run new pipe and leave the old buried.

[Cantick]

3 hours ago, Conor said:

I'd avoid going near the AC pipe unless it's leaking badly. It's not doing any harm. We've thousands of miles of AC pipe in this country.

 

A 2" AC pipe will have more than three times the capacity of a 32mm mdpe pipe. If you have current flow/pressure issues, they will get worse. You'd want to replace with 50mm or 63mm mdpe.

 

If you do replace the ac main, leave it buried and lay the new pipe in a new trench. Either that or pipe burst. Either way, it'll be a big chunk of money.

Unfortunately the the old pipe is not laid deep enough and we get three or four leaks a year. The current pressure and flow is not bad even with the 32mm pipe at the front end. How much pressure/ flow drop would be felt if the whole run was 32mm pipe?

[Conor]

27 minutes ago, Cantick said:

Unfortunately the the old pipe is not laid deep enough and we get three or four leaks a year. The current pressure and flow is not bad even with the 32mm pipe at the front end. How much pressure/ flow drop would be felt if the whole run was 32mm pipe?

Replace it then. You'll have a load of leaks on that pipe as it is and that'll be dropping your pressure a bit.

 

There are a lot of variables and I'd need more info to model it, but I'd not lay 32mm pipe over that length. If laying a new pipe, you may as well go up a diameter or two, as the biggest expense will be the excavation, laying and backfilling. Do you own all of the land along the pipe route? You want to keep a good 1-2m away from the AC main. E.g. if it runs along the verge of a lane, lay the new pipe on the other side