Samson 3730 Series Mounting And Operating Instructions page 37

Attachment to the control valve – Mounting parts and accessories
Should other valve accessories be used
which vent the actuator (e.g. solenoid valve,
volume booster, quick exhaust valve), this
exhaust air must also be included in the pur-
ging function. The connection over the
adapter at the positioner must be protected
with a check valve mounted in the piping.
Otherwise the pressure in the positioner
housing would rise above the ambient pres-
sure and damage the positioner when the
exhausting components respond suddenly.
37
EB 8384-3 EN