This standard specifies the characteristics of welded straight nippels for inch series pipe couplings, 37°, spherical, in heat resisting steel, for aerospace applications. Nominal pressure: Class D in accordance with 6771
DS/EN 4552:2003 history
2003DS/EN 4552:2003 Aerospace series - Pipe coupling, 37°, spherical, in heat resisting steel - Straight nippels, welded end - Inch series