An injection system comprises a fluid control member and a reciprocating member; wherein the fluid control member is configured to form a carbon composite-to-metal seal with the reciprocating member in response to application of a compressive force; the carbon composite comprising carbon and a binder containing one or more of the following: SiO2; Si; B; B2O3; a filler metal; or an alloy of the filler metal, and the filler metal comprising one or more of the following: aluminum; copper; titanium; nickel; tungsten; chromium; iron; manganese; zirconium; hafnium; vanadium; niobium; molybdenum; tin; bismuth; antimony; lead; cadmium; or selenium.