If it is the same R .whites company im thinking of. It was near Dudley road hospital, which use to have R. whites pop. My dad and grandad worked at the company.
Have you looked here Dave
https://forum.birminghamhistory.co.uk/showthread.php?t=2762&highlight=R.White
Yes that's right, along with Rawlings, who were already owned by R. White. Did you work for the B'ham R. White?
The idea with syphons is they are a 'sealed' container and the heads and spout are cleaned before re filling, but I see your point. Yes they do sometimes explode when filling if the glass has a fracture from use. When they are new, or reconditioned, they are tested to twice the normal working pressure. The old swing stoppers were a good idea, everything was sterilised and re used. No waste.