Honeywell ABV DU144 and DU145

[John Carroll]

The DU144 gives excellent control over different by pass requirements especially where high pump heads are required. Even with pump heads of 6M or more a broad range are bypass flows are available, but the DU145 (angled type) has completely different flow characteristics (bottom flowchart) so basically useless with a high pump head requirement, ie pump head of 6M with ABV set to index 6 gives a minimum flowrate of ~ 800 LPH, 13.3LPM forcing the installation of a manual (throttling) by pass valve in line with this ABV if bypass requirements are less than this type of ABV, these characteristics seems true of all ABV manufacturers but I certainly wasn't aware of it until I read of someone posting on here who required a high bypass flow of > 14LPM, 840LPH using a 8M pump and I thought it was a faulty ABV as the straight type will provide this at a index setting of 6 (0.6) or less but I was looking at the wrong type of ABV, the DU144 instead of the installed DU145.