2002-04-27 http://www.nibs.org/cmcnews.html
http://www.nibs.org/MetricNews/2qtr99.PDF Go to the first site above to access the newsletter index of the Construction Metrication Council and to the 2-nd link to specifically download the one pertaining to pipe. We have discussed on this list in the past the fact that the inch names given do not reflect the true size of any of the pipes, inside or out. A metric version of the names exists and uses the prefix DN, for diameter nominal. This version takes into account the actual size of the pipe and is not just a name conversion from FFU to SI, as is done in the French case below. For example, the 1/2 inch is real DN15, the 3/4 inch is DN20, etc. If you ever measure pipe you will find that it comes much closer to a true metric size then FFU. The electrical pipe (conduit) I have in my home has a 16 mm id and a 18 mm od. I used precision dial callipers to measure it. And water pipe has a 16 mm od and I will assume a 14 mm id, as I have no spare piece lying about. Thus an average of 15 on the water pipe. And when I measured it, the needle varied <0.1 mm from true zero. So maybe the original British designers of pipe were using metric in secret. John ----- Original Message ----- From: <[EMAIL PROTECTED]> To: "U.S. Metric Association" <[EMAIL PROTECTED]> Sent: Saturday, 2002-04-27 12:36 Subject: [USMA:19709] RE: Metric Standards and the USMA On Sat, 27 Apr 2002 10:50:11 -0400, [EMAIL PROTECTED] (Joseph B. Reid) wrote: >French plumbing follows British plumbing pipe standards, However the names >have been changed to metric. A 1/2" pipe is "un treize" (a 13) and a 3/4" >is "un dix-neuf" (a 19). Except that UK pipes are now 15, 22 and 28 mm. Chris -- UK Metric Association: http://www.metric.org.uk/
