Ooops!
I've never really thought about it before, but what kind of steam pressures & temps are we talking about from a stm train loco?
In English units please!

On average, depending on the type of engine you are talking about 250 psi at 405 degrees fahrenheit, but 300 degrees higher if using superheated steam, with say bulleid pacific classes being run at 280 psi at 750 degrees F., superheated.

I hate dislike steam! It can be nasty stuff - as your photo shows - it used to amaze me in my days of the Grey Funnel Lines when people, who should have known better, would go searching for superheated steam leaks with the back of their hand! 
We used to steam at 550psi 850oF
And they are reluctant to work on the wet soggy low pressure stuff we have at work.

Yes Andy, it must be treated with great respect!

Your great fear on the footplate, apart from blowbacks from the firebox, is that the drain cocks are not fully opened with steam blown through, before applying the regulator after a stop.
Any water in the cylinder can destroy it, or at least blow the cylinder covers off, when the piston pushes against said water, as water cannot be compressed!! Very nasty!!
