@orly61 Hi you asked me directly for an estimate of how many actuations would be required to bed in valves.

The answer is too complex to be reliably given, I will explain why this is.

Different manufacturers each have their own methods of fabricating valves although the process is the same for all manufacturers, the fine detail does vary due to variations in raw materials and fabrication methods and tooling.

Additionally when a manufacturer fabricates a series of products which are designed to be identical they do not end up being identical, this is due to inaccuracies in manufacturing tolerances allowing minute variations and is unavoidable.

Also different manufacturers use different metals for the valves and even the same metals may have slight differences within the metal depending upon the foundry they came from and the different proportions of each element in the alloy.

Monel for example is a mixture of copper nickel iron manganese carbon and silicon. different monels used by different manufacturers have slightly different amounts of each element in the alloy and this alters the hardness of the resulting monel.

These differences make valves wear in or bed in at different rates and for this reason it is impossible to predict the rate of bed in for any instrument when we do not fully understand the hardness of each of the metals.

We do know the position of each metal on Mohs scale, but the Mohs scale value of each metal is simply not accurate enough to assess complex wear rates to be able to answer your question.

Add to this the variations in the amount of oil present around the valves in use and we have another factor which also alters significantly the rate of bed in or break in of the valves and this renders the Mohs hardness value moot.

The result is it cannot be predicted how long it will take or the number of actuations it will take to bed in or break in any given set of valves. There are simply too many unknown variables.

The answers given by ROWUK DR GO flugelgirl and the other knowledgeable members are the best anyone can come up with.

Or to put the answer simply, - It depends.

All I am prepared to say is, it will take as long as it takes.