Net Weight Filler Product Supply - AODD

Consistent controllable flow is important for accuracy when filling with the net weight method.  Air Operated Double Diaphragm (AODD) pumps are notorious for their inconsistent flow rates.  In order to alleviate the surges from the AODD a surge dampener must be installed.  

The attached illustration shows the proper plumbing for the surge dampener.  The dampener is piped at the outlet of the pump.  A throttling valve serves to introduce back pressure to the line and improve performance of the dampener.  Air is supplied from a common line to both the pump and dampener from the filler.  The filler typically supplies air only when needed.  While it is possible to simply close a down stream pump and stall or deadhead the pump, this results in a pressurized feed line which can cause splashing when the vale is again opened.  By controlling air flow to the pump, splashing is greatly reduced.