New main from 25mm pipe to 20 to 15 copper before stop cock?

[loziv]

Hi

We have just had a new water main installed and a new stop cock in a new location ( through the wall into our kitchen cabinet under the sink)

They have used insuduct but I just wanted to know why they used 25mm pipe up until the 90 degree bend in the ground then 20mm mdpe pipe in the insuduct then 15mm copper through the wall into our internal stop cock

Is this normal, as looking over the insuduct instructions it's not how they describe how insuduct should be installed and why they reduced from 25 > 20 > 15 which must affect the flow rate into the property!

We were told that you can't connect 25mm mdpe into
a stop cock and had to reduce it to 20 then 15 which
I realise now is not the case

 

[St0rmer66]

No reason why they couldn't have come in as far as the stop cock in 25mm and had a reducing stop cock. Insuduct specifically says it's for 25 and 32mm pipes. 20mm is usually only used for repairs to an existing pipe and not for running a new pipe.

That said, is the flow rate improved and sufficient for your needs? A small length of reduced size pipe is unlikely to affect it a massive amount. But if I'd paid for a renewal in 25mm I'd be annoyed at this lack of attention to detail, screams of cutting corners to me. Perhaps they ran out of 25mm and didn't want to buy more etc.

 

[loziv]

Exactly they had plenty of 25mm pipe so no idea why they then used 20 and then 15mm copper before getting to our stop cock

The flow is marginally better than before but it's hardly noticeable it just annoying that you just want a good job done and you trust them
Yet they don't do a proper job which is frustrating

 

[St0rmer66]

The sooner you bring it up the better. Is there still access to get to the part where it reduces to 20mm? Are you in a position to withold any money owed until it is completed to your satisfaction?

I can't understand why anyone would do all that reducing... sounds like MORE hassle??

 

[loziv]

They would have to make one dig again by the insuduct as it's where the 25 mm goes into 20mm

We thought it was done to satisfaction it's only because it's leaking in about 3 places under our sink at the moment and I was looking into this and insuduct I started to question why they have reduced it down, when on the insuduct tech install it states 25 or 32 pipe going through to the stopcock

Would this reduction from 25 to 15 over say a metre or so before it enters our stop cock affect flow rates that much?

 

[St0rmer66]

Not if it's a 15mm stop cock and 15mm pipework after it.

 

[loziv]

It's a 15mm stop cock, pipework after is standard 15mm as normal in all houses

So it doesn't make a difference ? Ie if it was 25mm into a 25mm stop cock then to 15mm internal copper you are saying the flow would be the same?

 

[St0rmer66]

Wouldn't make a difference for that short of a distance. But it would over the whole length of the water main.