Flushing out slinkies and refilling?

[dilalio]

Several hundred metres of slinkies.
GSHP pipework, buried under ground and river.

Full of stale glycol and water.
Need to get it out and refilled with new mix.

Approx 500litres.

Have arranged for 1000litre IBC to flush it into with power flusher so that it has capacity to take more than required for dilution to fresh water.

This will be disposed of by waster company.

But, trying to figure best way to get the new volume of properly dosed blend into the pipes, as they will already be filled with fresh water! Not like filling an empty tube and waiting until it spouts out.

Any suggestions?

Cheers

 

[Madrab]

You will need to displace the fresh water with the mix I presume, is the fresh water going to drain? Presume the new mix containerised? Valve on the opposite end , then use a grey water pump to pump mix then shut off valve once mix container is empty?