WENTGATE Electron Beam Welders Models Manual WENTGATE Electron Beam Welders Models BW-510-PG, BW-502-PG and BW-602-PG. Operating and Maintenance Manual with a Supplement "Precision Filament Manufacture and Alignment Procedure". Manufacturers: Wentgate Models: BW 501 PG BW 502 PG BW 602 PG Contents: Operators Manual Maintenance Manual