lower lcp cavity portion is also of a narrowed diameter and it is that aspect of the valve design which secures the float flt u2032 into the lower lcp cavity portion in conjunction therewith the float flt u2032 means is characterized by a selection from the group consisting of it is substantially spherical and fully present in said lower lcp cavity portion it is disk shaped and fully present in said lower lcp cavity portion it is substantially tubular shaped with an upper lip present inside said lower lcp cavity portion said upper lip being of a diameter which is larger than that of the narrowed diameter of said lower end of said lower lcp cavity portion said substantially tubular shaped float flt u2032 means being at least partially encompassing of said projected rod r of said rod means which is projected out of said lower lcp cavity portion it is substantially tubular shaped with an upper lip present inside said lower lcp cavity portion said upper lip being of a diameter which is larger than that of the narrowed diameter of said lower end of said lower cavity lcp portion said substantially tubular shaped float flt u2032 means being at least partially encompassing of said projected rod r of said rod means which is projected out of said lower lcp cavity portion said float flt u2032 means having at its lower extent an open bottom ob 0 but otherwise closed cavity for containing an air bubble it is substantially tubular shaped.