Nebojsa has used a considerable amount of ingenuity in the construction of his heater.

He was unable to purchase a suitable metering valve, and so he made up his own using a standard 19mm (3/4") pipe collar for the body, into which he silver soldered the inlet connection.

The valve assembly was made out of a regular water tap bonnet as seen more clearly in the photo at left. To achieve the necessary fine adjustment he removed the normal tap washer and drilled the shaft to accept a steel needle which he ground to shape with a high speed grinder.

The seat is merely a plug which has been drilled out and had the outlet pipe soldered into place with the end of the pipe forming the seat against which the needle seals.

I am so impressed with this idea, that I will be making one up to test for my own heater, as I feel that the long needle will give a much finer adjustment of flow. In my present heater, there is only 1/4 of a turn from minimum flow to maintain a flame, to the maximim flow that my heater can burn,... although the valve will open further.