further formed with an opening 130 substantially opposite the exterior channel 126 and extending through the wall of the sleeve 124 the sharp corner 132 between the inside surface 134 and the flat end 136 of the sleeve 124 functions as a valve seat for the valve 110 as will be described hereinafter the operator for the valve 110 includes a solenoid coil 138 wound on a bobbin 140 which is then encapsulated in plastic 141 and surrounded by a magnetic yoke 142 the yoke 142 has a pair of opposed openings 144 and 146 axially aligned with the bobbin 140 a non magnetic plunger tube 148 extends into the bobbin 140 the plunger tube 148 is flared outwardly at 150 where it is welded to an externally threaded metal stamping 152 the other end of the plunger tube 148 is welded to an internally threaded pole cap 154 which extends outwardly from the yoke 142 a magnetic pole piece 156 is threaded into the pole cap 154 the pole piece 156 is formed with a circumferential groove for holding an o ring 158 which seals the plunger tube 148 the plunger tube 148 the metal stamping 152 the pole cap 154 and the.