when you turn the internal dial up on your varistream it increases the cut off pressure.
macmac don't believe me then fine but the fact remains tht the vessels are only designed to be used up to a max of 147psi and everytime I disconnect the pole it gets very close to the limit - I'd rather just be careful. Anyway whats wrong with putting the vessel before the pump or more to the point WHY would I put it after the pump (don't know why I have a vessel in each van - already got 2 after my ro)
Every time you disconnect your pole everything from the pump to end of hose is under the same pressure- pipe, connections, stop-end etc. surely, if the pressure was so great that it was of concern evrything would start popping off & bursting?
I've run 2 DI vessels for 4 years & on some big jobs taken them out of van & run them from mains, again with stop ends on hose. both vessels have been under massive pressure & never failed nor had even to be maintained in any way. A typical domestic radiator has a max working pressure of 10 bar & yes, if was subjected to such pressure for 15 years, with natural corrosion it might just fail. The concequenses of this happening though could be quite drastic ( flooded house ). What would be the worst could happen to you with a 50 quid DI vessel in the back of your van?
You worry too much
As for DI after pump, in my experience doing it this way is less likely to get air in the system from the connections on the DI's, that's all.
Tony