The amount of droop your pressure regulator will see is dependent on three key factors: diaphragm area, stroke length, and spring rate.
Sometimes referred to as the ‘Proportional Band’ or ‘Offset’, droop is an inherent characteristic in all self-operated and pilot-operated regulators. Droop is a decrease in outlet pressure from the set value due to an increase in media flow rate.
Three factors that affect droop (offset):
1) Effective Diaphragm Area
– The larger the diaphragm, the more sensitive, therefore more accuracy
– Very consistent manufacturer to manufacturer
2) Spring Range
– The more sensitive the spring, the more accurate the regulator
– Jordan Valve has more spring range options than any competitor
– Note: Ideal to be at the top of the range
3) Stroke Length
– The shorter the stroke, the more accurate when ranging flows
– Jordan’s sliding gate has 1/3 of the stroke of any globe style equivalent
– A short stroke reduces diaphragm wear
– Below, the Jordan MK60 is the blue line, a well-known competitor is the pink line
