Sight Glass on the Trevithick Boiler

Not real happy about this one, but it is necessary if I am to run the dredger engine in public, at club meetings etc.

The original dredger engine had 3 taps to check on the boiler water levels,  like this.

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An earlier stage of construction, using taps to reveal the boiler water level.

Unfortunately that setup is unacceptable for boiler certification, so I have installed a sight glass using the same penetrations.

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The red colour does not help.  But when I run the engine on steam, this is what will be seen.   Functional, but nothing like the original.  If I use compressed air, or steam from an outside boiler (i.e. my burner not being used), I can reinstall the taps.

The sight glass is a bit short, but it should comply with the regulations.

I have spent another half day experimenting with different spring configurations, so that the safety valve releases at 40-50psi.  Eventually I decreased the coil pitch of the spring, and the valve now releases at 45-50psi.  That will do.