On Fri, 28 Aug 2009 23:45:18 +0100, John MacLeod
wrote:

Yes. I run a caravan site and have come across that problem frequently.

If so, what use are
these repair fittings?

Very little :-(

Thanks, that explains it.

Someone mentioned HDPE but I could only find MDPE, will that do? How
come that doesn't burst, are the walls very thick?