The garden taps are plumbed in below-ground MDPE and connected to the
water main via a Floplast stopcock, which is at the bottom of a small
vertical access chamber. Something was leaking so I've dug-out the area
around the stopcock and think the problem is down to metric-imperial
mismatch, but I don't know enough about MDPE to know what I need.
The input of the stopcock is 17mm OD black (I assume that's 3/8"
imperial) and is not leaking. The output is 20mm OD blue pipe, which
fits loosely into a plastic retaining ring and O ring that fit into the
output side of the stopcock. The ring and O ring are about 21.2mm ID so
I assume are for 1/2", and that this is the problem. I think I need
replacement retainer and O rings for 20mm, but I can't find them.
What do I need?

On 26/04/2018 17:21, wrote:
The garden taps are plumbed in below-ground MDPE and connected to the
water main via a Floplast stopcock, which is at the bottom of a small
vertical access chamber. Something was leaking so I've dug-out the area
around the stopcock and think the problem is down to metric-imperial
mismatch, but I don't know enough about MDPE to know what I need.
The input of the stopcock is 17mm OD black (I assume that's 3/8"
imperial) and is not leaking. The output is 20mm OD blue pipe, which
fits loosely into a plastic retaining ring and O ring that fit into the
output side of the stopcock. The ring and O ring are about 21.2mm ID so
I assume are for 1/2", and that this is the problem. I think I need
replacement retainer and O rings for 20mm, but I can't find them.
What do I need?

You could always get a transition fitting - they are designed to go
between odd and irregular pipe sizes and types. BES have a good range of
such things.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 27/04/2018 11:58, John Rumm wrote:
On 26/04/2018 17:21, wrote:
The garden taps are plumbed in below-ground MDPE and connected to the
water main via a Floplast stopcock, which is at the bottom of a small
vertical access chamber. Something was leaking so I've dug-out the area
around the stopcock and think the problem is down to metric-imperial
mismatch, but I don't know enough about MDPE to know what I need.
The input of the stopcock is 17mm OD black (I assume that's 3/8"
imperial) and is not leaking. The output is 20mm OD blue pipe, which
fits loosely into a plastic retaining ring and O ring that fit into the
output side of the stopcock. The ring and O ring are about 21.2mm ID so
I assume are for 1/2", and that this is the problem. I think I need
replacement retainer and O rings for 20mm, but I can't find them.
What do I need?

You could always get a transition fitting - they are designed to go
between odd and irregular pipe sizes and types. BES have a good range of
such things.


I was hoping to find a metric lock ring to fit into the stopcock and
replace the imperial one (no luck so far). The problem with a
female-female transition is that I don't have any imperial pipe to run
from the stopcock to the adapter. I suppose I need a transition coupling
with a 1/2" male spigot on one side, but they all seem to be BSP
threaded, rather than plain.

wrote:

On 27/04/2018 11:58, John Rumm wrote:
On 26/04/2018 17:21, wrote:
The garden taps are plumbed in below-ground MDPE and connected to the
water main via a Floplast stopcock, which is at the bottom of a small
vertical access chamber. Something was leaking so I've dug-out the area
around the stopcock and think the problem is down to metric-imperial
mismatch, but I don't know enough about MDPE to know what I need.
The input of the stopcock is 17mm OD black (I assume that's 3/8"
imperial) and is not leaking. The output is 20mm OD blue pipe, which
fits loosely into a plastic retaining ring and O ring that fit into the
output side of the stopcock. The ring and O ring are about 21.2mm ID so
I assume are for 1/2", and that this is the problem. I think I need
replacement retainer and O rings for 20mm, but I can't find them.
What do I need?

You could always get a transition fitting - they are designed to go
between odd and irregular pipe sizes and types. BES have a good range of
such things.


I was hoping to find a metric lock ring to fit into the stopcock and
replace the imperial one (no luck so far). The problem with a
female-female transition is that I don't have any imperial pipe to run
from the stopcock to the adapter. I suppose I need a transition coupling
with a 1/2" male spigot on one side, but they all seem to be BSP
threaded, rather than plain.

BES, as someone just said do a 20mm or 25mm pushfit plastic tube to
plain 15mm or 22mm brass spigot (siuitable for a compression fitting,
but you need supports to stop it coming out axially as the olive won't
dent it much) adaptor.


--

Roger Hayter