Here is a normally-closed solonoid valve (the 24VDC  one) which i wish to use to keep open (or indeed closed) a pipe of water in a domestic household in UK
have many years experience in specifying and supplying solenoid valves.
Customers seldom need the degree of details you are asking for, exception is product development, as seems to be your case,and should because of this be properly supported from supplier and producer directly.
There could be several reasons you are not able to get information from your supplier:
-the supplier do not bother with this degree of service
-the data are not readily avialable (good producers and suppliers should be able to answer relatively fast)
- the variation from valve to valve, defaults in practical applications, and failures will be larger and wide compared to data.
- data never checked by producer.
Conclusion: try producer directly or a competitor to compare (some hundreds on world-wide basis, at least some tens available within UK?), or try to get a supplier to support with a number of valves to check out and experiment.
If this is a one-off case you will probably just have to buy 'best available' for all components and jump into testing directly if dependability is important.

MORE NEWS