Expansion

[dormermike]

Hello

I am going to "plumb out" a dead shower pump which currently has x2 22mm (inlet) and x2 15mm (outlet) isolator taps.

All the fittings to the pump itself are 22mm (flexi quick fit) but not long enough to bridge directly. The 15mm taps on the outlet side connect to 15mm pipes which then open up to 22mm using copper fittings which is what the flexis are attached to.

I'll remove everything on the pump side of the taps, which currently rise out of chipboard flooring.

My plan is to make a pipe which will fit into each of the taps, so:

22mm pipe + 22-15mm coupling + 15 mm elbow + 15mm pipe (30cm and 12cm for each) + 15mm elbow + 15mm stub of pipe into tap.

How would i accomodate expansion? Or is that not relevant here (guess it only applies to the hot anyway). The reason I ask is, there is not a lot of flex in the copper risers and i'm not sure i want to put any strain on anything, given its all boxed underneath a chipboard floor.

Thanks
Mike

Here is a pic:

Untitled

• dormermike
• 14 Mar 2011
• 2

 

[oldbuffer]

Don't worry about the expansion. A metre of pipe will expand by 1.33 mm for a temperature rise of 80 degrees C. Your vertical pipes to the gate valves will easily accommodate that. Expansion is linear, so if your "bridge" is only 1/2 metre, expansion will only be 0.67 mm.

 

[dormermike]

Awesome answer, thanks!!!