Valve seal problem! Urgent

songxguan

Hello, everyone. I'm doing reseach about the rubber seal between a valve disc and valve body. Most company use rubber compressed in them. but how much should the "compress pressure" be? As u know, if the pressure is too little, the fluid (water) will leak; otherwise, the "wear" will be greater.

Is there a prediction or empirical equation about the relation between "seal compressed pressure" and the "hydaulic pressure", which the rubber seal ring can resist.

It's very urgent, does anyone know? please, help!