Connecting 25mm MDPE to galvanized pipe

[thediyman]

I'm trying to improve the water flow at my home. It is supplied by 7/8" [external diameter] galvanized/iron pipe which I am replacing with 25mm MDPE.

Some background - I contacted Severn Trent and they quoted around £900 to reconnect to my MDPE which is just too much money. I called them to ask why it is such a high cost and they said the water main is the other side of our road and they would need to dig up the road to replace the pipe from their main to the stop tap and then dig up the pavement to reconnect my MDPE to the stop tap.

So I thought I'd replace the iron pipe up to the boundary of my house to see if that makes much difference to the flow first. There's probably around a 10m run of iron to the house so I'm hoping it will help.

The question is, how can I connect my 25mm MDPE to a sawn off 7/8" galvanized iron pipe? Can anyone advise? Thanks!

 

[Biggles..]

Look at Philmac fittings or Viking Johnson.

Lee

 

[tonybhoy]

You need a transition coupling like one of these below,probably the philac is your best bet but there are other types available.


http://www.tycowaterworks.co.uk/upe/product2.php?ID=233&Dept_ID=68


http://www.philmac.co.uk/Products/UTC.asp

 

[muggles]

If you're not replacing all the way back to the outside stopcock then I suspect you won't achieve your aims - if the flow is being restricted by the 7/8 OD galv then it still will be unless you remove all of it.

 

[thediyman]

Thanks for the responses; I'll try the Philmac connector out.

>If you're not replacing all the way back to the outside stopcock then I
>suspect you won't achieve your aims - if the flow is being restricted by
>the 7/8 OD galv then it still will be unless you remove all of it.

This was my initial thought. But I then read something on a newsgroup somewhere that made me change my mind - unfortunately I can't find the posting any longer.

The post basically said that the flow rate is proportional to the resistance to flow and to the pressure. If the pressure stays constant then the flow rate is proportional to the resistance to flow. Based on this, the theory is that each metre of the old pipe provides a higher resistance to flow than the MDPE will and so I should see an improvement in flow by effectively reducing the resistance. If my theory is wrong then the only option at present will be to pay Severn Trent £900 to replace their pipework. Also, there are people in the Yellow Pages saying they solve flow problems so I might give them a try if it comes to it.