How to set the delayed opening time of the air valve?

Question

The manufacturer said that the air valve would be delayed by 1-2 seconds, but now the new model delayed by 0.1 s. How to set the delayed opening time of the air valve? Thank you.

Yashodhan Joshi · Answer

Hello Jing, 
 Which product are you using? HAMMER? 
 You can set the delay in air valve opening or closure by defining air flow curves. You can use the custom air flow curve option to introduce this by setting the air flow rate to zero for negative pressures. See the below article for more details; 
 Modeling Reference - Air Valves 
 In the above article, refer the section titled Using a Custom Air Flow Curve 
 Hope this helps.