0000921739-97-000012 SC 13G 1 19970212 NONE CENTRAL SPRINKLER CORP 0000766041 3490 232328106 PA 1031 SC 13G 34 005-37077 97526364 451 N CANNON AVE LANSDALE PA 19446 2153620700 451 N CANNON AVE LANDSDALE PA 19446 DELAWARE MANAGEMENT HOLDINGS INC 0000921739 6282 232693133 DE 0331 SC 13G ONE COMMERCE SQUARE 2005 MARKET ST PHILADELPHIA PA 19103 2157512926 ONE COMMERCE SQ 2005 MARKET ST PHILADELPHIA PA 19103 SC 13G 1 000092173997000012-001-seq1-sc-13g.txt 13G FORM