Eccentric Reducers on Pump Suctions Redux - FOT/FOB

These two sites contradict each other; McNally Institute says FOT at pump suction and The Pump Handbook (via Fluide Design) says it should be FOB. Any comments out there? Could the Pump Handbook actually be wrong?

<a href="http://www.mcnallyinstitute.com/CDweb/p-html/p015.htm">http://www.mcnallyinstitute.com/CDweb/p-html/p015.htm</a>

"Make sure eccentric reducers are not installed upside down at the pump
suction. The top of the reducer should go straight into the suction flange."

"Use eccentric reducers rather than concentric reducers at the pump
suction. Concentric reducers will trap air. Be sure the eccentric reducer is not installed up side down."

"Be careful to install the eccentric reducer with the straight side up
to prevent trapping air at the pump suction."

<a href="http://www.fluidedesign.com/download-free/guidel_pump_syst-extract.pdf">http://www.fluidedesign.com/download-free/guidel_pump_syst-extract.pdf</a>

"Always use an eccentric reducer at the pump suction when a pipe size
transition is
required. Put the flat on top when the fluid is coming from below or straight (see
Figure 1) and the flat on the bottom when the fluid is coming from the top. This will
avoid an air pocket at the pump suction and allow air to be evacuated."

[This text is followed by a graphic showing a *flat-on-bottom* eccentric reducer directly connected to a pump suction with suction line coming in from the top (as if feeding the pump from a piperack). The image is credited to "The Pump Handbook published by McGraw-Hill.] Received on Fri Feb 25 19:35:00 2005