a syphon package incorporates a deformable , resilient plastic sealing member which , in its normal position , blocks passageway for dispensing seltzer water stored under pressure in the package . tube , valve sealing member and insert are assembled by bonding insert to flange with sealing member in place . the resulting assembly is then bonded to interior wall of necked opening . a syphon head has a one - piece actuator bonded to body , with actuating rod supported on resilient diaphragm for downward movement by lever to deform sealing member out of sealing engagement with passageway .