|External Spring on Reservoir Spill
On building the pressure reservoir for my JS-26 I decided to use an external
spring in the relief valve. I did this because I was struggling to adjust
both the spring pressure and the opening pressure inside.
My solution was to add a stem to the valve that extended up through the vent
hole. This stem fits through a small piece of wood that spans the opening
and is fitted with a light spring. The valve is actuated with a length of
string attached to the bottom centre of the valve and the other end fixed
to a cross piece fitted across the corner of the reservoir.
The valve could also be easily actuated from the outside using a block set
to the travel distance above the stem.