New branch to existing clay pipe

jell1234 · Post: # 99783Post **jell1234** Mon Jul 07, 2014 9:45 am

Hi there,

I need to connect a new branch junction to an existing underground 4" clay pipe which I intend to do using a PVC Y junction. I know I need to use adjustable couplings to connect the old clay to the PVC, but all the Y junctions available seem to be either double or triple socketed, and obviously the adjustable coupling wouldn't go straight from clay spigot -> PVC socket. So what is the usual way of doing this? Should I just use a short section of PVC pipe at the socket end to "convert" the socket into a spigot that I can use the adjustable coupling on?

Many thanks for you help.

Mon Jul 07, 2014 9:55 am

I know what you mean exactly
yes you just need to insert a 140mm piece of pipe into the PVC Y junction

then use your AC4000 adaptor
you normally need to use at least 2 slip collars for this as well

LLL

jell1234 · Post: # 99788Post **jell1234** Mon Jul 07, 2014 10:00 am

Thanks for the reply - thanks for confirming what I thought. I'm not sure what you mean about using 2 slip collars as well though. I thought it would just be

clay pipe --> adjustable coupling (AC4000) --> 140mm piece of PVC pipe --> Y junction socket, then at the outlet side Y junction spigot -> AC4000 -> clay pipe.

Am I missing something?

Post: # 99790Post **seanandruby** Mon Jul 07, 2014 10:57 am

.....I think LLL is assuming your joining into an existing run where you would need to use slip collars. If it is an open end run don't worry just join on with ordinary collars.

jell1234 · Post: # 99791Post **jell1234** Mon Jul 07, 2014 11:01 am

Hi seanandruby

Thanks for taking the time to reply.

Yes he is correct that I am joining into an existing run, but I don't understand the purpose of the slip collars as well as the adjustable couplings. What are the slip collars for and where do they fit in relation to the adjustable couplings?

Excuse my ignorance, I'm a keen DIYer but haven't done a lot of underground drainage yet - appreciate your advice to make sure I am doing it right.

Cheers.

Mon Jul 07, 2014 12:52 pm

its ok on with the ad400 or ad4000 they act like a slip collar anyway.

the important part is that the new bit is almost to the mm the same size as the section you cut out.

no 30mm play to make it easy etc thinking hte collar with do the job it'll just provide a nice spot for a blockage

so if your y and short stub of pipe is 350mm long say your cut in the clay wants to be 350mm or as near as possible and wants to be a straight clean cut

teh slip collars are for when insert a connection into 110mm plastic with no rubber adapters they allow you to get the section of pipe in and connected

jell1234 · Post: # 99794Post **jell1234** Mon Jul 07, 2014 12:59 pm

Hi GB_Groundworks,

That makes sense - thanks for the advice about getting the length exactly right. I suppose if I leave a bit of extra length on the Y + pipe stub then make the gap in the clay pipe a fraction shorter then I can cut to exact size by trimming off the PVC stub, much more confident cutting PVC to exact size than the clay!

Many thanks to all for all your advice.