According to one aspect, a manifold assembly includes a skid, a low pressure manifold connected to the skid, and a high pressure manifold connected to the skid. In another aspect, the high pressure manifold has a modular configuration so that the high pressure manifold is disconnectable in whole or in part from the skid, and reconnectable in whole or in part to the skid. In yet another aspect, the high pressure manifold includes high pressure modules, all of which are in fluid communication with each other and each of which is adapted to be in fluid communication with at least one pump. In still yet another aspect, the low pressure manifold includes one or more flow lines, the high pressure manifold includes fittings, and the manifold assembly includes vibration isolators to dampen dynamic loading, the vibration isolators being disposed between the fittings and the one or more flow lines.