You can get Hep2O flexible hoses, but they also do a bewildering array of tap connectors. I've got 10mm Hep2O pipe taking hot to various basins and am also considering the same for cold to cisterns. Is there any reason not to like the HD26A/10W which is plastic hand tighten and includes a rubber washer. It's all white which helps it to blend in. Is a visible Hep2O pip considered naff vs a flexible hose? 10mm Hep2O is more discrete in many ways.

 

Plumbing Superstore have a good price on them (£1.70inc each) but delivery on top pushes it up. 

1 hour ago, MortarThePoint said:

I've got 10mm Hep2O pipe taking hot to various basins and am also considering the same for cold to cisterns

The flow rate is much lower than 15mm, which is fine for low lpm flow rate outlets, however, I have done this a couple of times and then noticed the cisterns take around twice as long to refill. 
 

Not a problem in say a cloak WC, I actually plumbed one like this early on this week, but if you wake up to use an ensuite and flush the loo, you don’t want the torture of waiting an age for the sound of it filling to stop.  
 

I stay in a lot of hotels and the one I’m in atm has a gravity CWS that fills the WC’s. Takes bloody ‘forever’ for it to shut up so my brain can tune back out. 
 

I’d recommend sticking with 15mm feeds to all WC’s or accept the above bug. 

42 minutes ago, Nickfromwales said:

The flow rate is much lower than 15mm, which is fine for low lpm flow rate outlets, however, I have done this a couple of times and then noticed the cisterns take around twice as long to refill. 
 

Not a problem in say a cloak WC, I actually plumbed one like this early on this week, but if you wake up to use an ensuite and flush the loo, you don’t want the torture of waiting an age for the sound of it filling to stop.  
 

I stay in a lot of hotels and the one I’m in atm has a gravity CWS that fills the WC’s. Takes bloody ‘forever’ for it to shut up so my brain can tune back out. 
 

I’d recommend sticking with 15mm feeds to all WC’s or accept the above bug. 

 

That's a good point since the maximum flowrate through a 10mm pipe is probably around 10L/m[1] so a 6L flush would take 36 seconds. That maximum flow rate is even for short sections dropping relatively high pressures.

 

For a larger diameter pipe, I guess it is limited by the filler mechanism itself.

 

Edited September 4Sep 4 by MortarThePoint

25 minutes ago, MortarThePoint said:

That's a good point since the maximum flowrate through a 10mm pipe is probably around 10L/m[1] so a 6L flush would take 36 seconds

Plus turns, bends, restrictions of joints and inserts, and more   The pipe alone isn’t representative of ‘real life’ (in my direct experiences). 

inside my grohe concealed cisterns the flexi from the twist stop  to filler valve is narrow bore, probably 8mm I’d guess so bottleneck there too.

Just now, crispy_wafer said:

inside my grohe concealed cisterns the flexi from the twist stop  to filler valve is narrow bore, probably 8mm I’d guess so bottleneck there too.

Yup, which means ‘don’t add to the problem’