Gasket and pressure/Temperature rating Standards

[selmagis]

Here is 1514-2:

[link Point to another website Only the registered members can access]
Here is 1092-1:2002:

[link Point to another website Only the registered members can access]

[SuzzH]

Hi All,
Can anyone help me to point to the requirement that the gasket need to cover at least 80% of the joint area? I saw some info about that but couldn't find in the standard... I could be missing... your help will be much appreciated...