00372nam a22001457a 4500 1801 1801 200204b ||||| |||| 00| 0 eng d 621.197 N873 1415 Northcroft, L. G. Steam trapping and air venting 3rd London Hutchinson 1952 172p. Steam Traps BK 0 0 ddc 0 621_197000000000000_N873 0 4732 CL CL 1953-02-25 A. H. Wheeler 621.197 N873 01524 2020-02-04 BK