QDB1: Overdose B, A Dose too Short

The B dose has overshot, forcing an A dose that, when combined with B, is too large for the mix manifold capacity.


Check for pressure pulsations: 

  1. Close all the manifold valves. 
  2. Turn on the circulating pumps and all the booth equipment (such as fans and conveyors). 
  3. Check if the ProMix 2KE is reading any fluid flow. 
  4. If the ProMix 2KE shows there is fluid flow and there are no leaks from the gun or any other seals or fittings, the flow meters are probably being affected by pressure pulsations. 
  5. Close the fluid shutoff valve between the fluid supply system and the flow meter. The flow indication should stop. 
  6. If necessary, install pressure regulators or a surge tank on the fluid inlets to the ProMix 2KE to reduce the fluid supply pressure. Contact your Graco distributor for information.

See Ratio Low Error and Ratio High Error, R1 and R4.

It may be necessary to restrict the flow rate through the component B dose valve by adjusting its hex nut.