Hi All – Martin Evans in his description of his 7-1/4" Highlander Black Five gives a drawing for the use of in-line water check valves (ME 3 February 1967) but from what I can see makes no reference to exactly where and how they should be fitted. It is also interesting to note that he opts for the use of in-line valves in place of valves mounted in the top feed unit as for the prototype and also as adopted by Don Young for his 5" gauge Black Five. I would be interested to hear the views of builders who have opted for the use of in-line valves and what are the advantages/disadvantages of using them. One obvious question arises regarding just how thet should be mounted i.e whether vertically or in the horizontally, the latter implying of course that the balls would not naturaly be resting their seats. Does this then mean that one would have to adopt the use of springs in order to keep the balls on thteir seats? All views and opinions would be much appreciated – Reg