Hello,

I ordered a spare brew valve for my Mitica. I noticed a difference with the original brew valve (besides the fact that the original is all brass, and the replacement has a steel stem), namely the original one has indentations on the four edges of square part holding the seal:



Whereas the new one does not have any indentations:



I searched online and saw images of both types but found no explanation.

1) Why are there the indentations?
2) Can I safely replace the indented one with the non-indented one?

Thanks for any insight...
Nicolas

Indentation are to help the valve pin engagement point with the camme during the rotation of the camme itself.

The indentations have no purpose at all once the valve is in the machine. I don't know why they're there, maybe they have some purpose in the machining process, maybe they're a measuring mark on the brass square rod from which the part is machined by some suppliers.

Once in the machine, that mark is completely hidden down in the bore of the E61 head and interacting with nothing.

Interesting! So I suppose I can just plunk it in there and forget about this riddle

I misunderstood the OP question, never mind, JRising is right.