BS ISO 7319:2021 pdf download – Aerospace — Fluid systems — Interface of 24° cone metric couplings.
1 Scope This document defines the geometry of the interface of removable 24° cone couplings for fluid systems in aircraft. The connection with the pipe of each one of the connecting elements can be of different design. This document specifies the dimensions which allow the interchangeability of the male and female elements and of the nut used for the connection. The dimensions define the maximum volume of the male fitting. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 5855-3, Aerospace — MJ threads — Part 3: Limit dimensions for fittings for fluid systems 3? Terms? and? definitions No terms and definitions are listed in this document. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — IEC Electropedia: available at http://www.electropedia.org/ — ISO Online browsing platform: available at https://www.iso.org/obp 4 Coupling assembly and sealing principle The coupling comprises three elements as follows. a) A female element including a frustum with a cone angle equal to 24°, with which the male element comes into contact to provide sealing. The contact line is a circle with a theoretical diameter, E. b) A male element, included inside a shell composed of two frustums connected by a spherical section with which the female element comes into contact to provide sealing. The contact line is a circle with a theoretical diameter, E. c) A nut allowing assembly of the male and female elements of the coupling. 5 Dimensions The dimensions shall be as shown in Figure 1 and given in Table 1.
Point A: origin at E/2 from the XX′ axis Point B: point located at a distance R from point A, on the perpendicular to the line tilted 12° relative to XX′ and passing through point a Point C: located at B/2 from the XX′ axis and at a distance P from point A Line CD: tangent drawn from C to the arc of the circle with centre at B and radius R Line EF: tangent tilted 12° 50′ relative to the XX′ axis on the arc to the circle with centre at B and radius R. The point of tangency thus obtained is designated E NOTE The profile involves exclusively those machined male elements which do not lose their shape. Nevertheless, the male element can be in the form of a sleeve fitted over the end of the pipe and which, during coupling to the female element, is compressed onto the pipe and changes its shape such that the correct profile is obtained.