New Water Main 25mm or 32mm...????

[DIYGavlar121]

Hi, having an extension done at the mo and part of the work involves having a new water main laid in to the house from the water meter on the pavement. The distance is about 15metres, we generally have good water pressure in the area. The old pipe is original from 1955

My builder has asked if I want a 25mm or 32mm plastic water pipe laid but he doesn't know the difference in performance..!!

Which one should I go for to give me max water pressure in the house..??

Thanks for any advice.

 

[omegaman]

If you want max water pressure then the obvious choice would be 32mm.

 

[gas4you]

The pressure will remain the same whatever size you go for.

What will change, is the flow rate. 32mm will give greater flow.

 

[stardanny]

Urm.... I thought the bigger the pipe is , the more the flow rate.

The water pressure remain the same no matter what size the pipe is.

If you have unvented hot water, I'll go for 32mm.

Dan

 

[DIYGavlar121]

OK thanks for the reply, just trying to understand the diff between flow rate and water pressure.!!??

I've just done a quick test on present system and it was delivering 17litres in a minute, what's considered a good pressure/ flow rate..??

cheers guys

 

[Whitespirit66]

Pressure is the amount of force that water flows through a pipe. Measured in BAR or lbs per sq. inch.

Flow is the volume (eg litres per min) of water flowing through a pipe.

Big pipes shift large volumes of water. Think of a sewer, high flow, low pressure.

A pin hole in a pipe would give great pressure of the escaping water (shooting several feet), but would have a very low flow or volume of water.

 

[MarkSmith]

I've just had my old lead pipe (i/d about 15mm) replaced with 25mm MDPE, and to be honest that's enough pressure for me. Now if I turn the kitchen tap on full (it's the sort where you can do that in one movement) water hits the sink with such a force that it sprays back up and I get a face full of water. Quite glad I didn't go for the 32mm!

 

[Bon]

I've just had my old lead pipe (i/d about 15mm) replaced with 25mm MDPE, and to be honest that's enough pressure for me. Now if I turn the kitchen tap on full (it's the sort where you can do that in one movement) water hits the sink with such a force that it sprays back up and I get a face full of water. Quite glad I didn't go for the 32mm!

Get yourself one of these

That is, unless you like washing your face everytime you turn your tap on

 

[MarkSmith]

Gosh, £45

 

[Agile]

The 32mm pipe is so little more than the 25 mm pipe and the cost of pipe about 5% of the cost of digging and burying it that there is no point in having the smaller size.

The pipe has to be buried at a min of 750 mm and should be laid by a water regs qualified installer or the water supplier's inspector called to look at it before its covered.

It does not sound as if you builder is qualified to do anything much!

Tony

 

[Bon]

I suppose a snorkel would be cheaper!

 

[Bon]

The 32mm pipe is so little more than the 25 mm pipe and the cost of pipe about 5% of the cost of digging and burying it that there is no point in having the smaller size.

The pipe has to be buried at a min of 750 mm and should be laid by a water regs qualified installer or the water supplier's inspector called to look at it before its covered.

It does not sound as if you builder is qualified to do anything much!

Tony

Is any builder??

I've just been trying to explain to a Main Contractor that even with all the best will in the world, our lads can't draw a 63mm MDPE main through a 4" plastic duct!!

 

[Agile]

I have to say that I have met some quite well qualified and knowledgeable builders.

Where it goes wrong is that they assume that they know all about heating and try to specify a system and then get some east european to install it and then wonder why it does not work well.

I was called at 6 pm on a saturday when I was getting ready to go to a party by a builder whose client was returning in three hours and had no hot water anywhere in spite of two boilers, a megaflow and two showers.

Stupidly I agreed to help him out as he was panicking! He had this Turkish installer who was completely out of his depth. I managed to get the two showers to give some water and the Megaflow to be heated by the immersion so they had hot water.

When I got to the party the food was all gone! The pittance he gave me was probably more than a days wages to the Turkish but it did not make me feel well paid for that time and day on an energency call.

Tony