Concrete water tank connector

[defadog]

Hi all, hoping someone can come up with a cuuning plan for me.

I have a rain water tank which holds about 6 tonnes of water. When it was built, the outlet was imbedded in the concrete base using 3/4" galvanised cast pipe With a 90 degree elbow embedded level with the internal base of the tank. No idea when it was built, we have been here 14 years and it was in place when we moved in.

Having emptied the tank to clean it, it is apparent the outlet pipe is rusting internally and getting blocked. I wish to fit a new 22mm pipe in copper into the side of the tank, but cannot find an easy way to connect through the 100mm tank wall. My questions are

Does anyone know of an extended flanged tank connector that would do the job?

If not, can I get a tight enough fit of a pipe into a compression fitting to end-feed solder it? My idea is to use two of these https://www.screwfix.com/p/flomasta-compression-tank-connector-22mm/36982 using flange End on one side soldered directly to the pipe and compression end on the other again soldered directly onto the pipe.

This would effectively extend the fitting as though it had been cut in half and an extension added. All other options considered!

Thank you.

 

[defadog]

Update. The concept worked just fine, giving me an extendable tank connector. If trying this, use a tight fitting dowel inside the compression fitting to prevent solder seeping past the compression collar as you solder it.

One minor problem, tank wall is actually 410mm thick...and came across what I suspect is a steel I beam or similar embeded in the concrete. So plan on hold whilst I reassess options.

 

[martygturner]

It will probably just be the concrete reinforcement mesh. If the galavinesed pipe is accessible from the outside why not just tap it through with a sledge and use that holle with a bit of resin sealent. or reline it with some plastic pipe shoved / pulled through it. The flow will be cut a bit but if the pipe was rusty you might not notice.

 

[jeff the gasman]

Fit a siphon pipe instead. Once primed it’ll run forever or until yo run out of water.