① Test instrument—Steady flow testing machine

② Testing basis：

ISO 5840-2:2015

③ Steady-state forward flow：

Transvalvular pressure differences on the inflow and outflow sides of the valve were measured at 5 L/ minute intervals at a flow rate of from 5 L/ minute to 30 L/minute. 

④ Steady state leakage：

Valve leakage was measured at 5 isobaric nodes at a backpressure of 5.2 kPa–26 kPa (40 mmHg–200 mmHg).