Hi Alan ,

An injector can certainly be used for feeding a small stationary engine boiler but it is not always best choice .

Any one injector has a feed rate which cannot be varied very much so to use just one to maintain boiler level 'automatically' over a long period with varying demands for steam is tricky .

Two ways forward :

(1) Fit an injector with more than adequate capacity and turn on and off manually as required .

(2) Fit two injectors . One small one which can be on most of the time to keep some water going into the boiler all the time and one larger one turned on as required for fast top ups .

Injectors will work for extended periods of time but are prone to 'knocking off' and will not usually restart themselves . 'Knocking off' occurs when any minor disturbance interrupts steam or water flow – most common causes are a water droplet in the steam or an air bubble in the water .

Many people prefer pumps – either power driven or hand worked – and it is actually a bit unusual to see injectors used on small stationary engine boilers .

Many full size boilers had steam powered reciprocating pumps . One of these would be interesting to model . Most common types are Scotch crank and Weir types .

Regards ,

Michael Williams .

Edited By MICHAEL WILLIAMS on 26/04/2012 23:45:29

Hello again ,

(1) Injectors are generally quiet in operation but you can usually hear a slight ' chirp chirp ' noise when they are working properly .

(2) Just for interest :

My earliest boilers were simply filled up at start of a running session and then allowed to cool down and filled again when the water was all gone . Not very scientific but quite satsfactory with simple pot boilers and I sometimes achieved 40 minutes of running between fill ups .

MikeW