File: PVE-4711, Last Updated: Nov 17/2010, By: LB

It’s that time of year again. The weather is getting colder, Christmas displays are in the stores and pressure vessel engineers are thinking about code updates.

Under National Board registration, a manufacturer will create a production drawing and state “latest code and addenda” under the code conditions block. A calculation set will be made to the current code and addenda. Copies of the vessel can be manufactured for the rest of the calendar year. After the year end rolls around one of two things happens. Either the code calculations are re-run (easy to do with commercial software) or the calculation set is reviewed and signed off that no code changes affect the calculation set. Production continues for another year. The drawing does not get updated until a code update forces a design change or some manufacturing detail changes.

Those familiar with the CRN system will realize that we crazy Canadians have succeeded in making this simple process more difficult and more expensive. In Canada we do not allow the words “latest code and addenda” on pressure vessel drawings when they are being registered. When the vessel is submitted for CRN registration, the drawing states an actual year and addenda. The calculation set is also done to the same year and addenda. After getting a CRN, non-Canadian manufacturer often revise the drawing set to show “latest code and addenda” so that the drawing does not need to be unnecessarily updated every year.

If the vessel is registered in one province in one year, and then the manufacturer wants to register it in another province in a later year, then the calculation set needs to be updated. The drawing no longer matches the calculation set so it needs to be updated. The updated calculation no longer matches the one registered with the first jurisdiction. Two choices are available: 1) update the registration with the first province, then register in the second – the CRN number is the same in both provinces – or – 2) Get a new CRN number in the second province. The vessel will end up with two CRN numbers. This becomes a nightmare if the vessel ends up in a province that does not match the CRN number on its nameplate (think shipping a vessel to a customer in one province who puts it on a skid and ships it on to a different province).

I have been told that the jurisdictions have been trying for years to work around this unnecessary and expensive complexity. For now we wait.