I'm about to add a feed to a new sink which involves a fairly long run
of pipe. I'm going to use 15mm plastic and Speedfit fittings as I
have used them before and like them.

However I want a few valves to allow me to isolate the new run (that
means a valve in the loft) and to isolate the sink tap (which means a
valve under the sink). The Speedfit valves seem horribly expensive
compared with all the other Speedfit stuff so I'm wondering about
alternatives.

So, firstly, can I use ordinary 15mm compression fittings on the
Speedfit pipe, I'm fairly sure the answer is yes but I'd like to be
sure.

If I can use ordinary fittings then which of the following would be
best:-

http://www.toolstation.com/shop/Plum.../sd2696/p67155

http://www.toolstation.com/shop/Plum.../sd2696/p14624

What I'm really asking is whether the ball valve is significantly
better than the other as regards flow constriction?


--
Chris Green

In article , writes
I'm about to add a feed to a new sink which involves a fairly long run
of pipe. I'm going to use 15mm plastic and Speedfit fittings as I
have used them before and like them.

However I want a few valves to allow me to isolate the new run (that
means a valve in the loft) and to isolate the sink tap (which means a
valve under the sink). The Speedfit valves seem horribly expensive
compared with all the other Speedfit stuff so I'm wondering about
alternatives.

So, firstly, can I use ordinary 15mm compression fittings on the
Speedfit pipe, I'm fairly sure the answer is yes but I'd like to be
sure.

Yes, no problem, just make sure you use the appropriate pipe insert.
It's actually my preference to use compression fittings on speedfit
where they might be subject to movement.

If I can use ordinary fittings then which of the following would be
best:-

http://www.toolstation.com/shop/Plum...lve+Handled+15
mm/d20/sd2696/p67155

That's not a full bore valve and will add a small restriction to the
flow to the tap. On mains pressure you may not notice it however.

http://www.toolstation.com/shop/Plum...Valve+15mm+Blu
e/d20/sd2696/p14624

Although not mentioned in the text, the swelling in the body shown in
the photo indicates that this is a full flow valve that will not
restrict flow. It is the safe option if you want max flow and easy
isolation.

What I'm really asking is whether the ball valve is significantly
better than the other as regards flow constriction?

Yep, a full flow ball valve is just like having a full bore pipe when
open and a good make will reliably cut off the flow.
--
fred
it's a ba-na-na . . . .

In article , fred writes

Although not mentioned in the text, the swelling in the body shown in
the photo indicates that this is a full flow valve that will not
restrict flow. It is the safe option if you want max flow and easy
isolation.

ps: if you don't mind using a screwdriver to isolate the supply then
this will do the job at lower cost:

http://www.toolstation.com/shop/p11495

it will be a full ball valve but is more compact w/o the lever (or
butterfly).
--
fred
it's a ba-na-na . . . .

On Wed, 18 Jan 2012 15:40:22 +0000, wrote:

However I want a few valves to allow me to isolate the new run (that
means a valve in the loft) and to isolate the sink tap (which means a
valve under the sink).

Why two valves?

So, firstly, can I use ordinary 15mm compression fittings on the
Speedfit pipe, I'm fairly sure the answer is yes but I'd like to be
sure.

Yes, but you must use a pipe insert, in fact you should use an insert
in the end of the pipe for every joint. This makes the already
smaller bore of plastic pipe even smaller. As for Speedfit valves
they really restrict the flow, a 22mm Speedfit valve has hole through
it the same size as the ID of 15mm tube...

http://www.speedfit.co.uk/Home/Techn...ort/FAQ-s.aspx

What I'm really asking is whether the ball valve is significantly
better than the other as regards flow constriction?

Both are ball valves... The isolation valve will restrict the flow,
the lever operated one looks to be full bore but doesn't say it is.
If this is a gravity system use the full bore type.

--
Cheers
Dave.

fred wrote:
In article , fred writes

Although not mentioned in the text, the swelling in the body shown in
the photo indicates that this is a full flow valve that will not
restrict flow. It is the safe option if you want max flow and easy
isolation.

ps: if you don't mind using a screwdriver to isolate the supply then
this will do the job at lower cost:

http://www.toolstation.com/shop/p11495

it will be a full ball valve but is more compact w/o the lever (or
butterfly).

Yes, it's just that I'm never really convinced that they won't get too
sticky to be turned easily with a screwdriver.

Thanks for the other comments.

--
Chris Green

Dave Liquorice wrote:
On Wed, 18 Jan 2012 15:40:22 +0000, wrote:

However I want a few valves to allow me to isolate the new run (that
means a valve in the loft) and to isolate the sink tap (which means a
valve under the sink).

Why two valves?

Because it's a long run, I want to be able to isolate it in case of
problems. Also it would be a pain to have to climb up into the loft
to isolate it at its start when doing some work on the tap at the
other end.


So, firstly, can I use ordinary 15mm compression fittings on the
Speedfit pipe, I'm fairly sure the answer is yes but I'd like to be
sure.

Yes, but you must use a pipe insert, in fact you should use an insert
in the end of the pipe for every joint. This makes the already
smaller bore of plastic pipe even smaller. As for Speedfit valves
they really restrict the flow, a 22mm Speedfit valve has hole through
it the same size as the ID of 15mm tube...

http://www.speedfit.co.uk/Home/Techn...ort/FAQ-s.aspx

I do always use inserts, that's a point about them reducing the bore
though, maybe I shouldn't worry too much about the effect of the valves.


What I'm really asking is whether the ball valve is significantly
better than the other as regards flow constriction?

Both are ball valves... The isolation valve will restrict the flow,
the lever operated one looks to be full bore but doesn't say it is.
If this is a gravity system use the full bore type.

OK, thanks.

--
Chris Green

In article , writes
Dave Liquorice wrote:
On Wed, 18 Jan 2012 15:40:22 +0000, wrote:

Yes, but you must use a pipe insert, in fact you should use an insert
in the end of the pipe for every joint. This makes the already
smaller bore of plastic pipe even smaller. As for Speedfit valves
they really restrict the flow, a 22mm Speedfit valve has hole through
it the same size as the ID of 15mm tube...

http://www.speedfit.co.uk/Home/Techn...ort/FAQ-s.aspx

I do always use inserts, that's a point about them reducing the bore
though, maybe I shouldn't worry too much about the effect of the valves.

This might be a case where Hep2o pipe with its thinner and short
shouldered metal inserts would be better (the pipe's more manageable
too).
--
fred
it's a ba-na-na . . . .

If it's hidden and there's plenty of space go for the long lever: easy
to operate, easy to see the state. The screwdriver ones are neat and
compact, but can stiffen and burr.

On 18/01/2012 15:40, wrote:
I'm about to add a feed to a new sink which involves a fairly long run
of pipe. I'm going to use 15mm plastic and Speedfit fittings as I
have used them before and like them.

However I want a few valves to allow me to isolate the new run (that
means a valve in the loft) and to isolate the sink tap (which means a
valve under the sink). The Speedfit valves seem horribly expensive
compared with all the other Speedfit stuff so I'm wondering about
alternatives.

So, firstly, can I use ordinary 15mm compression fittings on the
Speedfit pipe, I'm fairly sure the answer is yes but I'd like to be
sure.

If I can use ordinary fittings then which of the following would be
best:-

http://www.toolstation.com/shop/Plum.../sd2696/p67155

http://www.toolstation.com/shop/Plum.../sd2696/p14624

What I'm really asking is whether the ball valve is significantly
better than the other as regards flow constriction?


As others have said, compression joints are fine with Speedfit pipe as
long as you use the right inserts.

Use full-bore lever valves such as
http://www.screwfix.com/p/full-bore-...lve-15mm/13103 which
will make sure that you don't restrict the flow, and will be easier to
operate after a long period of inactivity. Valves with only a
screwdriver slot are very unreliable, and plastic butterflies can shear
off if the valve is tight - but a metal lever is much more robust and,
of course, provides lots of leverage.

One thing which nobody else has mentioned is how to react the operating
torque. If the tap simply has a piece of flexible pipe either end,
there's nothing to react against if it takes a lot of torque to turn it.
You either need to find a way of holding the tap itself in position, or
need to use short lengths of copper pipe either side of the tap, held
down by pipe clips. You can then join copper to plastic with either
push-fit or compression connectors - whichever you prefer.
--
Cheers,
Roger
____________
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checked.

Roger Mills wrote:

One thing which nobody else has mentioned is how to react the operating
torque. If the tap simply has a piece of flexible pipe either end,
there's nothing to react against if it takes a lot of torque to turn it.
You either need to find a way of holding the tap itself in position, or
need to use short lengths of copper pipe either side of the tap, held
down by pipe clips. You can then join copper to plastic with either
push-fit or compression connectors - whichever you prefer.

Yes, I'm always a bit worried by this, it'll be T-eed off some copper
pipe so I guess that valve can be all copper one side at least and
maybe I'll do what you say and have a short length of copper the other
side as well.

--
Chris Green

On Wed, 18 Jan 2012 18:21:59 +0000, wrote:

http://www.speedfit.co.uk/Home/Techn...ort/FAQ-s.aspx

Forgot to mention that soft copper olives are recomended as well not
hard brass ones.

I do always use inserts, that's a point about them reducing the bore
though, maybe I shouldn't worry too much about the effect of the valves.

All the restrictions are cumulative... Probably not a problem if this
is mains pressure starting at a handful of bar but if gravity and
only 1 bar to start with all the little pressure drops across each
restriction soon add up.

--
Cheers
Dave.

On 18/01/2012 23:03, YAPH wrote:
On Wed, 18 Jan 2012 15:40:22 +0000, tinnews wrote:

If I can use ordinary fittings then which of the following would be
best:-

http://www.toolstation.com/shop/Plum...solating+Valve
+Handled+15mm/d20/sd2696/p67155

http://www.toolstation.com/shop/Plum...ver+Ball+Valve
+15mm+Blue/d20/sd2696/p14624

What I'm really asking is whether the ball valve is significantly better
than the other as regards flow constriction?


Advantage of push-fit valves is you can rotate them so you can actually
get at the handle. With compression the valve rotates on the pipe as
you're tightening it and it's the devil's own job to get them to end up
with the lever facing the way you want.


Not if you've got two hands (and two spanners)! You hold the valve in
the right orientation using one spanner on the flats on the body, and do
up the compression nut with another spanner.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On Thu, 19 Jan 2012 13:12:58 +0000, Roger Mills
wrote:

Advantage of push-fit valves is you can rotate them so you can actually
get at the handle. With compression the valve rotates on the pipe as
you're tightening it and it's the devil's own job to get them to end up
with the lever facing the way you want.


Not if you've got two hands (and two spanners)! You hold the valve in
the right orientation using one spanner on the flats on the body, and do
up the compression nut with another spanner.

And it still puts a slight twist in the plastic pipe, so the valve
handle ends up slightly off line. You just compensate for that halfway
through the tightening.

On Thu, 19 Jan 2012 09:15:32 +0000 (GMT), "Dave Liquorice"
wrote:

I do always use inserts, that's a point about them reducing the bore
though, maybe I shouldn't worry too much about the effect of the valves.

All the restrictions are cumulative... Probably not a problem if this
is mains pressure starting at a handful of bar but if gravity and
only 1 bar to start with all the little pressure drops across each
restriction soon add up.

Which is why, in my own place, I've used the copper/brass inserts - as
being thinner so less accumulative restriction.
For everyone else's I used the plastic ones.