This figure shows the two types of close coupled outlet valves. In the first valve (Type 1), the smallest diameter of the large end of the flare (b) must be greater than the inside diameter of the outlet line (d) plus the depth of the flare (h). Also, the greatest distance from the valve seat to the small end of the flare (a) must not be more than the diameter of the outlet line (d). In the second close coupled valve (Type 2), the seat of the valve is flush with the inner wall of the pasteurizer. The greatest distance from the valve seat to the inner wall of the pasteurizer (a) must not be greater than the inside diameter of the valve outlet (d). The diameter of this passage must be uniform.