has a non metallic plug closing one end thereof the plug has the hall effect sensor oriented therein to closely oppose the magnet on the magnet holder so that movement of the armature and resulting corresponding movement of the magnet will cause the hall effect sensor to produce a signal indicative of movement of the armature application_number US 80504407 A description the solenoid portion 10 of a solenoid operated valve is illustrated in the drawing the solenoid portion 10 includes a solenoid body 11 having a hollow cylindrical non metallic bobbin 12 on which is wound many turns of wire 13 to form an annular coil 14 the annular coil 14 is encased in a non metallic synthetic resin shell 15 which has a radially outwardly extending flange 16 having a plug socket 17 formed therein so that electrical contact prongs 17 a are exposed in the socket for electrical connection to a plug not shown the contact prongs 17 a are electrically connected to the wire 13 forming the annular coil 14 so as to facilitate the provision of electrical energy to the coil 14 in this particular embodiment the shell 15 is oriented inside a steel cup 18 having a through hole 20 in the bottom wall 19 thereof and with the flange 16 projecting through a slot 18 a in the rim of the open end of the cup 18 the shell 15 is retained inside the steel cup 18 by press fitting a washer 18 b into the open end of the steel cup in this particular embodiment a compressible spring o ring type seal 18 c is oriented between the washer 18.