Outside mains value and 22mm or 15mm for water softener?

[Sup9]

I'm looking to install a Monarch Master HE ( or the Midi He, not decided yet). I have 20mm mains pipe coming into the house, then the mains valve is 20mm->15mm converting, then I have 15mm all the way inside the house. I have couple of questions before I can get the materials for the job,

1. Outside mains valve
I find the below right in front of my driveway, I assume this is my outside mains valve and the red one is the mains valve? I can't seem to move it by hands is there a special tool for it?
View media item 104121View media item 104118

2. If I can manage to switch off the outside mains valve, I 'd like to change the inside mains valve to leveller ball valve. I measured the pipe and it's 20mm, should it not be 22mm as all the valves on screwfix are 22/15/28mm?
View media item 104119View media item 104120

3. If inside mains valve is changes to 22mm one, is it worth to have 22mm pipe feeding the water softener then convert to 15mm to feed the inside of the house? I don't know whether doing this way I can have minimum drop of water pressure and flow? or should I just convert to 15mm from the mains valve and feed the water softener? I can order the softener with 15mm or 22mm bypass valve and fitting kit.

Thanks a lot for any advices.

 

[denso13]

Blue MDPE comes in 20mm external, roughly 15mm internally http://www.mdpewaterpipe.co.uk/mdpe-product-information/mdpe-pipe-dimensions. Just connect the softener to the existing 15mm copper.

 

[JohnD]

Is it 20mm external diameter?

Is it plastic or steel?

 

[Sup9]

Blue MDPE comes in 20mm external, roughly 15mm internally http://www.mdpewaterpipe.co.uk/mdpe-product-information/mdpe-pipe-dimensions. Just connect the softener to the existing 15mm copper.

lol never thought the incoming pipe is plastic. The plumber that came in the other day said I had good incoming cause it's 22mm.....
So I wouldn't bother with 22mm, all the way 15mm then. How about the mains valve (the inside one), should I get a new ball valve or just keep the current one (don't touch it if not failed approach?)?

Is it 20mm external diameter?

Is it plastic or steel?

Yes 20mm external diameter. Tried to scratch the pipe and I 'm sure it's plastic. So it's the 20mm external 15.4 internal diameter MDPE pipe that denso13 linked.

 

[denso13]

should I get a new ball valve or just keep the current one

I don't think it is worth the trouble to be honest unless is it is causing problems. It wont improve the flow that much.

 

[Sup9]

I don't think it is worth the trouble to be honest unless is it is causing problems. It wont improve the flow that much.

Yea, tried it this afternoon I think it still shut off completely. Guess I'd better take one step at a time and get the plumbing work for the water softener right this time.