Front LHS Water Filter Valve Repair

It was 2012 when I last wrote about Sentinel 7109's water tank filter valves. There I described how they worked and could be used to drain water pipes to avoid frost damage.

Early in 2016 just after 7109 had begun her new steaming career, there was a frost forecast so I followed the procedure and removed the drain plugs to empty the pipes.

That evening I received an urgent phone call saying that water was pouring out of the LHS of the water tank. This was not good news 25 miles away on a dark cold night.

Investigation showed that the front LHS valve was not only emptying the pipes but the entire tank!

I consulted Justin Goold who informed me that although these valves had a phosphor bronze valve spindle, they had a cast iron valve seat. The seat tended to corrode over time leaving the valve unable to close properly.

The solution was to machine out the valve seat and replace it with a brass insert which would not corrode and hence be more reliable for the future.

I couldn't do this myself and it needed to be done quickly between steamings. John Goold did the honours and it now works as it should.

New brass valve seat insert

Many thanks to John and Justin. What would I do without you!