"Fash" wrote in message
...
Can't really see water hammer being a problem in a CH circuit,

That is why I suggested a suck it and see approach after making the point
originally. However, in other applications, it can happen and then I would
want to have a solution that relied upon the equipment design, rather than
on operating procedures. Procedures as the only way of avoiding problems is
always the last and least desirable option for any safety system.

Colin Bignell