Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

My only minor gripe about the Ragleth is that a set of operating instruction weren't included. I downloaded a set from Accucraft, which states that the boiler should be filled to the top and the blow down valve opened a turn while steaming up, allowing liquid water to flow down and out of the valve as the steam headspace (not sure if that's the correct term) builds, pressure rises and off it goes. I tried this method this a.m. and it works fine, although run time was about 5 min less than when I filled the boiler, removed 30ml of water and fired it up, ignoring the blow down valve.

So...

Does the valve serve any real purpose other than to relieve steam pressure at the end of a run?

Thanks,