CSN EN ISO 5211 This document specifies requirements for the attachment of part-turn actuators, with or without gearboxes, to industrial valves. The attachment of part-turn actuators to control valves in accordance with the requirements of this document is subject to an agreement between the supplier and the purchaser. This document specifies: - flange dimensions necessary for the attachment of part-turn actuators to industrial valves [see Figures 1 a) and 1 c)] or to intermediate supports [see Figures 1 b) and 1 d)]; - driving component dimensions of part-turn actuators necessary to attach them to the driven components; - reference values for torques for interfaces and for couplings having the dimensions specified in this document. Original English text of CSN EN Standard. The price of the Standard included all amendments and correcturs.