The paper reports concerted experimental and numerical investigation on the dynamic
behavior of a pneumatic pressure regulator valve. It has been pointed out that in
case of leakage, laminar flow may develop in the orifice cross-section and thus, the
isentropic or sonic orifice models applied in pneumatic simulation must be treated
with criticism. The tests showed that a spring-like behavior of the flexible seal
is essential for realization of small clearances of valve opening compensating the
leakage.
