... leaking proof steel ball fitted at both ends, in case glass pipe broken nominal flage size: DN20, needle valve fitted ... at bottom of the level meter for easy cleaning and sample taking purpose. Leaking proof ... steel ball fitted at both ends, in case broken of glass pipe.Nominal length: L=300, 500, 600, 800, ... )(I,II),L=300-1,700, HG5 HG-5 glass pipeline liquid level meter