Scott's Highland Services in London, Ontario, Canada makes excellent valves for Scottish Highland Bagpipes and Scottish Smallpipes. I use them on all my pipes and have found them to be much better than any other valve I've ever used. You can buy them directly from Jim Scott or I can mount them for you. There are two sizes:

Small Pipe Valve

This fits most Thracian blowpipes and any other blowpipe (bellows or mouth blown) that is less than ¾" in diameter. It usually requires no modification of the tenon end. All that need be done is strip off the old wrappings, cut the copper tab on the valve to fit the flat on the side of the tenon, and tie the valve on. Because of the reverse fold of the flapper it presses tightly against the opening and seals exceptionally well. The left picture shows the valve and the right shows it mounted on a blowpipe.

SmallPipeValve

Little Mac Valve

This fits most Rhodope and Macedonian blowpipes and any other blowpipe (bellows or mouth blown) that is ¾" or more in diameter. It is a more reliable valve than the Small Pipe Valve because the valve flapper and seat are a single prealigned unit but it requires significant modification of the tenon end. The tenon end must be cut flat and then the throat of the blowpipe must be reamed out to accept the stem of the valve. Scott's Highland Services sells the correct reamer if you choose to do this yourself, but I already have it and the tools to modify the blowpipe tenon.The left picture shows the valve and the right shows it mounted on a blowpipe.

LittleMacValve