This part of EN 10226 specifies the requirements for thread form, dimensions, tolerances and designation for jointing pipe threads, sizes 1/16 to 6 inclusive, for joints made pressure-tight by the mating of the threads. These threads are taper external and parallel internal and are intended for use with pipes suitable for threading and for valves, fittings or other pipeline equipment interconnected by threaded joints. An appropriate thread sealant or jointing compound should be used on the thread to ensure pressure-tight joints. NOTE 1 Threaded joints using taper external threads and taper internal threads are detailed in prEN 10226-2 NOTE 2 The requirements for taper external threads are identical in EN 10226-1 and prEN 10226-2 NOTE 3 For pipe threads where pressure-tight joints are not made on the threads see EN ISO 228-1 NOTE 4 prEN 10226-3 gives details of recommended gauging systems for the verification of thread dimensions and thread form.