1947 - 1/4" NPSMF 1/4" NPTM
1977 - 3/8" NPSMF 1/4" NPTM
1978 - 3/8" NPSMF 3/8" NPTM
1979 - 3/8" NPSMF 1/2" NPTM
1980 - 1/2" NPSMF 3/8" NPTM
1981 - 1/2" NPSMF 1/2" NPTM
1982 - 3/4" NPSMF 3/4" NPTM