300 TDi to Puma Bulkhead heater connection

Almost finished rebuild of 300tdi Auto with full Puma Bulkhead/dash.
Have been told that when connecting up the heater pipes from the rear of the TDi to the Puma
heater control valve i have to include a bypass loop because of the heater valve fully closing.

Thoughts/solutions/ideas and pictures please.

I recall this being a issue on the mark 2 golf where someone was supposedly scolded when the heater matrix ruptured and they recalled them to fit the bypass and pressure relief valve to eliminate the problem take a gander

Thank you Mystery for that link. Going to have to make up my own bypass using T pieces in-between the flow and return pipes,
Cant get it that close to the valve but it think it will help.

remember you will need a relief valve or the flow will take the easiest path the bypass there are several fitted to saab vacuum type https://www.ebay.co.uk/itm/271023467501?hash=item3f1a41ebed:g:fgEAAOSwft9asRQD r , cable operated https://www.t7design.co.uk/tx2-heat...=1&gclid=EAIaIQobChMIi6_ul7_C_wIVyp1oCR0wLg9z electric https://www.ebay.co.uk/itm/404205714926