All O-ring seal applications are categorized in terms of relative motion. In situations involving little or no motion relative to the seal, the O-ring application is STATIC. In situations involving reciprocating, rotating, or oscillating motion relative to the seal, the O-ring application is DYNAMIC.
Recently, one of our customers contacted us about a problem she was having with an O-Ring that sits on a siphon neck of a liquid nitrogen dewar. Here's what we did to help her.