A fitting for collecting or distributing high-pressure fluid via fluid transmission lines is provided. The fitting includes a body, and a plurality of apertures formed in the body in a common plane, intersecting inside the body such that all of the apertures are in mutual fluid communication. The fitting also includes first and second compression members positioned on opposing sides of the body and coupled thereto so as to exert a compressing bias to the body in an axis perpendicular to the common plane. The compression members each comprise a raised contact surface corresponding to the region of the body where the plurality of apertures meet, and through which the compressing bias is exerted. The fitting may be an elbow-fitting, a tee fitting, a cross-fitting, or some other configuration.