The Pitch Diameter of Pipe Taper Thread Measurement and Uncertainty Using Three-Wire Probe

Authors: J. Kloypayan, W. Pimpakan

Abstract:

The pipe taper thread measurement and uncertainty  normally used the four-wire probe according to the JIS B 0262.  Besides, according to the EA-10/10 standard, the pipe thread could be  measured using the three-wire probe. This research proposed to use  the three-wire probe measuring the pitch diameter of the pipe taper  thread. The measuring accessory component was designed and made,  then, assembled to one side of the ULM 828 CiM machine.  Therefore, this machine could be used to measure and calibrate both  the pipe thread and the pipe taper thread. The equations and the  expanded uncertainty for pitch diameter measurement were  formulated. After the experiment, the results showed that the pipe  taper thread had the pitch diameter equal to 19.165mm and the  expanded uncertainty equal to 1.88µm. Then, the experiment results  were compared to the results from the National Institute of Metrology  Thailand. The equivalence ratio from the comparison showed that  both results were related. Thus, the proposed method of using the  three-wire probe measured the pitch diameter of the pipe taper thread  was acceptable.

Keywords: Pipe taper thread, Three-wire probe, Measure and Calibration, The Universal length measuring machine.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1090894

References:

[1] JIS B 0262, "Measuring Method of Pitch Diameter of Taper screw Plug Gauge and Inspection.” JIS Handbook, pp.187-206, 1998.
[2] ISO 7-1, "Dimensions, Tolerances and Designation,” Pipe Thread Where Pressure-Tight Joints are Made on the Threads, 1994.
[3] EA-10/10, "Guidelines on the Determination of Pitch Diameter of Parallel Probing,” EA European Co-Operation for Accreditation, 1999.
[4] EA-4/02, "Expression of the Uncertainty of Measurement in Calibration,” EA European Co-Operation for Accreditation, 1999.
[5] Thomas M. Adams, "A2LA Guidelines for the Estimation of the Uncertainty of Dimension Calibration and Testing Results,” 2002
[6] J. Kloypayan, W. Pimpakan, "Measuring Accessory Component Design and Analysis for Taper Thread Measurement,” International Congress on natural Science and Engineering, pp. 180-186, 2013.
[7] J. Buajarern, K. Naoi, "Asia Pacific Metrology Program Intercomparison of high precision Roundness measurement,” APMP.L-S4 Roundness intercomparison Protocol, Version 3, pp. 16, 2012-2013.