Valve and choke stem packing assemblies

A stem packing assembly comprising:

• a first annular member defining a central axis;
• a second annular member defining a central axis coaxial with the central axis of the first annular member;
• and
• an annular energizing member defining a central axis coaxial with the central axis of the first annular member,
• wherein the first annular member comprises a PAEK, such as PEEK, wherein the second annular member comprises a PTFE, and wherein the annular energizing member at least partially comprises a PTFE.

A stem packing assembly comprising:

• a first annular member defining a central axis;
• a second annular member defining a central axis coaxial with the central axis of the first annular member;
• an annular energizing member defining a central axis coaxial with the central axis of the first annular member, the annular energizing member including a jacket and an energizing element, wherein, when viewed along a plane extending radially outward from the central axis of the annular energizing member, the annular energizing member includes at least one scraper;
• wherein the stem packing assembly has a leakage rate according to ISO 15848-1 of less than 1×10−4 mgs−1m−1 for at least 500 cycles at 160° C., and less than 1×10−4 mgs−1m−1 for at least 500 cycles at −46° C., and wherein the first annular member comprises a PAEK, such as PEEK, wherein the second annular member comprises a PTFE, and wherein the annular energizing member at least partially comprises a PTFE.