Re: Washout plugs and boiler check valves

Washout plugs are just that... brass threaded plugs which are generally located in the four corners (if your engine like hours has a keyhole boiler I don't know if later boilers which are not this design have four or two drain plugs ) of the mudring. To wash the boiler out you basically just wait until there's no pressure in the boiler ( maybe use the blowdown to lessen the pressure ) and then you just remove the plugs with a big wrench. When you're done rinsing you just replace them.
A check valve basically just consists of a tongue which is a thing which look sort of like a silver dollar, and a (circular) valve seat , which has a thing around it usually to prevent the tongue from escaping. All that happens is that when the injector or feed pump is not on, the tongue is held by boiler pressure against the seat which prevents water from leaking out ( in theory ) . When you put the injector / water pump on there is higher pressure on the side going into the boiler, the tongue is pushed forward, and in that position water can enter the boiler. Usually when you get "blow back" something has clogged the seat of the check valve, and it's therefore not seating properly and consequently some pressurized water from the boiler is coming back to the injector even when it's shut off. If you're confused maybe someone knows where you can find a photo of a disassembled check valve, when you see one you'll quickly understand what I mean.
My terminology is very rough as I don't really know the proper names for the components I mentioned, however I'm sure there are many folks who can fill in where I missed and provide the correct terms..
Regards,
Trevor H.
M.N.G.R.R.Co.&M.
Portland, ME