Installing outside tap - Help!

[vw]

I have already made up the Tee connection to branch off from water main. There is isolation valve at end of the copper pipe. Its position is ready to drill through the wall. I am about to buy the materials and finish the job following: I would be very much appreciated if you could have a look. Any commons will be great. Thanks

Materials (diameter is 15mm):

Self-cutting valve with check valve,
Wall plate elbow
MDPE or copper pipe
Drain off valve,
Fittings (90 degree, etc),

I also have few questions:

What is different between MDPE and copper pipe? Can I use MDPE pipe outside house (4 meter outside)? If both of them do not resist low temperature (frozen pipe), which material shall I use to lag them?
Is the check valve the same as the non-return valve?
Do I need another stop valve after water main?
Do I really need drain off valve?

Thanks

 

[BoxBasher]

Is the check valve the same as the non-return valve?
In the terms that you are speaking, yes.

Do I need another stop valve after water main?
Yes

Do I really need drain off valve?
Yes -although it depnds on the layout of your pipework


Installation should be as follows (after the tee off)

Isolating valve/stopvalve : Drain off : Double check valve (all inside the building).

Then the pipe should have protection/insulation as it passes through the wall and any exposed pipework (outside) should be insulated.

 

[EliteHeat]

Why not make life easy on yourself and use one of these

I'm not a plumber and know that they hate them. They are easy to fit though.

 

[Terrywookfit]

Why not make life easy on yourself and use one of these

I'm not a plumber and know that they hate them. They are easy to fit though.

Because you can **** quicker!!

 

[breezer]

Why not make life easy on yourself and use one of these

I'm not a plumber and know that they hate them. They are easy to fit though.

Because you can p**s quicker!!

Thats true, but didn't the OP first say

"Self-cutting valve with check valve"

its the self cutting bit that worries me

 

[Dan Robinson]

I know my G&t is a particulary stiff one but

Isolating valve/stopvalve : Drain off : Double check valve (all inside the building).

shouldn't that be:

Isolating valve/stopvalve : Double check valve : Drain off : (all inside the building)

???

 

[BoxBasher]

I know my G&t is a particulary stiff one but shouldn't that be:

Isolating valve/stopvalve : Double check valve : Drain off : (all inside the building)

???

Nope,

How do you drain the water out of the DCV if the drain-off is after?

Drain-off is to drain the water from everything after the stoptap.

Although not a regs requirement it makes things easier if the feed comes up not down...

 

[vw]

I know my G&t is a particulary stiff one but

Isolating valve/stopvalve : Drain off : Double check valve (all inside the building).

shouldn't that be:

Isolating valve/stopvalve : Double check valve : Drain off : (all inside the building)

???

Hi, thanks for the reply. I found the tap with check valve from screw fix, so do i need the non-return valve inside house. another question: which pipe shall I use to fit (MDPE or Copper pipes)?

Thanks again for all of you.

 

[yerino]

after you have teed of the mains feed all you need after it is a mini valve and then in the winter close the mini valve and drain the water through the outside tap itself to avoid freezing pipes.

and with check valves built in the tap you'll find they will block eventually and you will just end up breaking the bit insside the tap anyway, so sometimes it is better to fit a tap without a check valve built in.. altho it is against the water regs... but?? up to you!

 

[BoxBasher]

Hi, thanks for the reply. I found the tap with check valve from screw fix, so do i need the non-return valve inside house.

Yes,

taps with a built in Double check are only for making an existing (pre-'99) installation compliant.

For a new installation as you are doing, the double check must be seperate from the tap and inside the building.

 

[vw]

Thanks a lot for your help

 

[ChrisR]

after you have teed of the mains feed all you need after it is a mini valve

Generally, "mini valve" means nothing in plumbing.
If you mean the cheap screwdriver operated ball type, they aren't appropriate for garden supply where you want max flow, they're too restrictive.

 

[yerino]

after you have teed of the mains feed all you need after it is a mini valve

Generally, "mini valve" means nothing in plumbing.
If you mean the cheap screwdriver operated ball type, they aren't appropriate for garden supply where you want max flow, they're too restrictive.

To restricted?? It's main cold pressure!! The same on your cold tap :S

 

[Dan Robinson]

IMHO they should not be used anywhere! Too restrictive, too likely to leak. Too *****!


Edited as Chris rightly point out... Hangover is kicking in now... .

 

[ChrisR]

It's main cold pressure!!

Yerino you must be doubly dimwitted. Doesn't it occur to you that I know it's mains pressure therefore it's YOU who has a knowledge problem?

Flow is not the same as pressure

Dan I assume meant to say they shouldn't be used anywhere.... in which case I would tend to agree, the cheap ones are pretty awful.