A method of manufacturing a reinforced tubular membrane comprises the steps of manufacturing the tubular support from monofilament thread, impregnating the support with membrane dope and adjusting the inner and the outer diameter of the membrane. A coating apparatus comprises a casting bob and an orifice to adjust respectively the inner and outer diameter of the membrane. A tubular reinforced polymeric membrane comprises a tubular support and membrane substance. The tubular support is made of monofilament thread and has a sufficiently open structure (openings larger than 0.1 mm). Touching and/or engaging parts of the thread may be linked prior to impregnating the support with membrane dope. The support may comprise loops of the monofilament thread, which are also linked.