Which fitting to use?

[rolyatescort]

Hi Guys, sorry if this duplicates anything, in my lounge/dining room (open-plan) i have 2 rads, they're not up to scratch so i'm replacing them. I have worked out the BTU's required for the room and checked that my combi can cope with the more powerful rads. My problem is that the 2 rads that i have now are 1150mm long and the ones i'm replacing them with are 1000mm long, there is no scope without expense to move the pipes so i want to place 75mm spacer pies between the new rads and the original pipework (1000mm rad + 2 75mm spacer pipes = 1150mm). A guy at work who used to be a plumber has offered to make the pipes up for me if i buy the fittings and pipe, but when i went to my local hardware store the guy said don't bother getting it soldered use compression fittings instead. Is this viable? I have never heard of using compression fittings on central heating systems is it safe practice? Sorry if i'm asking a stupid question but i'm only a DIYer and as safety is paramount i don't want to get talked into something dodgy.

Thanks for any help you can give.

 

[kevplumb]

nothing wrong with compression fittings if used properly
dont look to nice tho

 

[Bahco]

Why not ask your plumber to simply extend your one pipe using a solder coupler.
Look neater and less hassle

 

[rolyatescort]

It would be a cleaner job but the rads are central under windows so both ends would have to be extended and the guy at work is an ex-plumber who still knows what he's doing and is doing it as a favour, i would ask him to come and do it that way but we live nearly 70 miles apart so its a lot of hassle for him to come and also the pipes are behind long curtains so don't actually get seen anyway.

My idea if using compression fittings would be to mount the rad in place then offer up the copper pipe mark off what i need and cut to length rather than just try to measure, is that a fair way to do it? My next question is does the pipe want to be measured from the face of the fitting on the rad to the face of the water pipe fitting or slightly longer? Is there a rule of thumb to work to?

Thanks for the advice so far.

 

[kevplumb]

if you look inside the fitting there is a shoulder inside known as a pipe stop for obvious reasons take your lengh from that
good luck

 

[rolyatescort]

thanks for that little tip kevplumb