BS EN ISO 228-2:2003 pdf free.Pipe threads where pressure-tight joints are not made on the threads – Part2:Verification by means of limit gauges.
BS EN ISO 228-2 specifies the verification, by means of hmit gauges, of cylindrical threads, the dimetisiuns and tolerances of which are given in ISO 228-1.
For industrial applications (see for example ISO 1179), it may be necessary to carry out additional checks.
2 References
ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads — Part 1: Designation, dimensions and tolerances.
ISO 1179, Pipe connections, threaded to ISO 228-1, for plain end steel and other metal tubes in industrial applications.
ISO 1502, ISO general purpose metric screw threads — Gauging.
3 Symbols and explanations
The symbols used in this part of ISO 228 are the same as those used in ISO 1502 for the ISO thread gauges, plus some additional symbols (n, S,u), as shown in table 1.
4 Function, control and use of gauges
4.1 Gauges for external threads and their check plugs
4.1.1 Solid GO threaded ring gauge
4.1.1.1 Function
The threaded GO ring gauge checks the virtual size of the external thread on the GO side (gauging the viltudl pitch diameter), i.e. it checks the maximum material limit of the ptch diamctcr, taking into account deviations ot form (departures from roundness and lack of suaiylitiiess of the thread axis over the gauge length) and pitch errors, helix variations and errors in the flank angles, which produce an apparent enlargement of the pitch diameter (virtual pitch diameter). In addition, this gauge checks whether the length of the straight flank is adequate, i.e. that the rounding at the root of the profile does not encroach too far upon the flank of the thread.
This gauge shows the maximum material limit.
4.1.1.2 Control
The solid threaded GO ring gauge manufactured accoidiiiy Lu the prescribed sizes shall be checked using the threaded GO and NOT GO check plugs and should be controlled regularly with the wear check plug.
If the NOT GO check plug is not used, other provisions shall be made so as to ensure that the maximum size of the pitch diameter of the threaded GO ring gauge is not exceeded.
4.1.1.3 Use
The threaded GO ring gauge screwed by hand, without excessive force, shall pass over the whole length of the thread. If this is nut possible, the thread does not comply with the specifications.
4.1.2 Threaded check plugs for new solid threaded GO ring yuge