A Groove depth is the machined depth into one surface, whereas a Gland depth consist of the groove depth plus diametrical clearance and is used to calculate seal compression. To create seal compression the groove depth must be less than the seal cross section. To compensate for this compression, the groove width must be greater than the seal cross section.
Static applications are more tolerant of material and design limitations than dynamic applications.
The maximum volume of the O-ring should never surpass the minimum volume of the gland. For reciprocating seals passing O-rings over ports is not recommended. Nibbling and premature wear and seal failure will result. The closer the application is to room temperature, the longer an O-ring can be expected to effectively seal. Avoid using graphite-loaded compounds with stainless steel, as they tend to pit the stainless steel surface over time.