Twin entry valves - injector pipes

[joncox]

I've got a perfectly happy 8mm microbore system.

One rad with (I've discovered) a broken off injector pipe - hence the poor flow.

Struggling to locate a supplier for a replacement. So, two questions:

1) Can I bodge it with a length of 8mm copper or plastic (easier since more flexible?)
2) How long (in relation to the radiator) should they be to achieve a decent flow?

many thanks

Jon

 

[kevplumb]

yes
2/3

 

[chrishutt]

Depends on arrangement of rad valve tapping in relation to bottom waterway of rad. typically double panel rads will require very flexible insert, whereas single panel rads can take a straight pipe (8 mm copper).

I don't think insert needs go that far into rad - typically 100mm or so. It's enough to stop short circuiting between flow and return.

You could alternatively ditch the twin entry valve and switch to separate opposite end rad valves.