Dust Cap 

Emco Wheaton F0499 Series API Dust Caps are designed and tested to take the punishment of the long haul. Requiring just a one handed operation, the caps not only seal and hold pressure, but they retain their shape even if dropped or mishandled. The caps are lightweight, corrosion resistant and best of all, they utilize a special, proprietary coating that makes them extremely durable. The finish will not chip or peel, even under extreme conditions.

Emco's F0499 API Dust Caps provide the durability - and more importantly - the pressure rated seal you demand.