Composite downhole tools for hydrocarbon production and methods for using same. The downhole tool can include an annular body having a valve assembly disposed therein. The valve assembly can include a first member preventing flow in a first direction through the annular body; a second member preventing flow in a second direction through the annular body; and a shoulder disposed on an inner diameter of the body between the first and second members. The shoulder can have a first end contoured to sealingly engage an outer contour of the first member and a second end contoured to sealingly engage an outer contour of the second member.