open vent system expansion pipe configuration

[elmsoft]

I am re-siting my boiler and the existing expansion pipe is no longer directly vertical above the flow and pump . What is the minimum vertical length of pipe I can get away with before a horizontal section to connect with the existing vertical pipe?

 

[denso13]

I am re-siting my boiler and the existing expansion pipe is no longer directly vertical above the flow and pump

It doesn't have to be, no strict rules about pipe lengths. You'll see all sorts of different layouts if you search for open vent images.

 

[elmsoft]

So if tee about 150mm and then run the expansion pipe horizontally for say1000mm before connecting to the vertical pipe to the tank that will be OK?

 

[denso13]

run the expansion pipe horizontally

I'd slope it upwards slightly so everything rises towards the feed and expansion cistern.

 

[elmsoft]

Excellent advice. On those numbers I could manage a 45 degree slope which would make for easy pipework.

Thank you so much.

 

[bernardgreen]

45 degree is good

 

[Bargain Bucket]

The pipe coming out of my indirect vented cylinder comes out vertically and then runs horizontally i.e. 90 degrees from the verical for a foot before rising straight up verically to the vent. Should it slope up slightly or will a short run of horizontal cause me no real issue?

 

[denso13]

Should it slope up slightly or will a short run of horizontal cause me no real issue?

No issues at that length.

 

[Bargain Bucket]

Thanks. Much appreciated.