PRESSURE B     [mv force + press]     P.mv - P.r = mv force
  1. P.r is the pressure variable in the mv force.  This pressure drop is determined by the stiffness of the mv stack.  A stiffer mv stack will produce LOWER pressures, given there are no changes to the bv stack  (see graph below). 
    • This is because a stiffer mv stack will create a greater press drop (P.mv - P.r).
  2. P.r is dependant on the icspr, and does not fluctuate with valving changes, but will increase slightly as the temperature increases.
    • The press increases due to thermal expansion of the oil (there is no actual gas with an icspr).
  3. Consider P.r as a secondary pressure and P.mv as primary. 
  4. 'mv force' comes from P.mv - P.r.
  5. If P.mv increases from a stiffer bv, P.r increases as well. 
    • See  'Fk Dyno . press c'  tab.