Earlier publications on static electricity by UPP/Petrotechnik have had an aura of science and sense that is now gone with the latest material published on http://www.upp.co.uk/nonconductive/index.html. The flyer and so called white paper contain several basic factual errors.
Quick introduction flyer - comments on a few statements:
"A non conductive pipiework system utilises material which naturally limits the amount of energy build-up; no means to dissipate energy is necessary."
It is well known that very high static voltages can build-up on non-conductive materials. Non-conductive is the term for materials that lack ability to "naturally limit the amount of energy build-up". Non-conductive objects cannot be grounded to allow dissipation of static charges. This does however not mean that dissipation is not necessary or desirable, especially in flammable atmospheres.
"With no additional continuity inserts required and greater flexibility, installation [of non-conductive systems] is simpler and faster"
Only if you don’t earth all conductive items. If you provide this earthing (essential with non-conductive systems, but only nice to have with conductive systems), the installation of non-conductive piping requires more effort. Also the effort involved in putting in an insert is pretty minimal compared to differences in the number of welds needed with different systems etc.
"A simpler annular test procedure means no line purging, no isolating from terminations, no site downtime and no added cost."
This is completely wrong! It is wrong that pipes must be emptied, disconnections made and the site closed to check continuity of a conductive piping.
UPP/Franklin also ignores the fact that in a non-conductive system ALL bonding and earthing of metal objects in ALL chambers and in the proximity must be checked. Not only are these arrangements more likely to fail, they are many and very time consuming to check. And in reality very few non-conductive installations will have proper bonding and grounding of metal objects even to begin with!
"The non-conductive pipework system is environmentally and operationally safe, offering protection from static risk, corrosion, and leakage and it is approved for use with all EN and UL recognised fuel types."
Since incidents with electrostatic ignitions in non-conductive piping systems in fact do occur it is completely wrong to say that the systems offers protection form static risk.
A non-conductive material is never completely safe to use in a flammable atmosphere.
"An energy brush discharge from a non-conductive (plastic) object cannot ignite fuel vapours because they are too weak"
This is simply not true. There is extensive scientific literature in the form of papers (key authors include Heidelberg, Gibson, von Pidoll but there are probably hundreds), textbooks and standards, for example CENELEC TR50404 covering the ignition of standard hydrocarbon fuel mixtures by brush discharges from plastic objects.
"Highly conductive biofuels pose no risk."
True, but not all bio-components are highly conductive. The charging of various classes of FAME, that can be put in biodiesel is unknown and could pose a risk. Diesel at present seems to charge less than petrol but this may not always remain the case.
"Non-conductive pipes generate much lower discharge energy than insulated conductive."
There are no insulated conductive pipes after they have been installed. They are then connected to earth. It is so much more common to see un-bonded, un-grounded metal objects like jubilee clips and fittings in non-conductive systems. And they can cause high energy sparks!
"When the flow stops any charge [in a non-conductive system] is naturally relaxed within minutes."
The charge will still be present when the driver disconnects the delivery hose and replaces the caps on the fill point connections. Asking the driver to wait 10-15 minutes after delivery to do this is NOT realistic.
"Hundreds of thousands of installations, around the world, demonstrate a wide margin of safety between levels of static electricity generated and those necessary to create an ignition hazard. No spark means no ignition of vapors."
Only if there are no ignitions, which is incorrect. Even if there were no ignitions, this could only prove that there is a margin, not how wide it is. There could be a wafer thin margin that would be eroded by a slight change in conditions. Indeed this is what the voltage measurements done by Hearn suggest.
"In contrast, artificially conductive plastic pipework is somewhat new and the pipe-to-pipe connectors used do not have the same track record that is associated with non-conductive pipework."
The first conductive KPS pipe was installed in 1996, which is 15 years ago. The track record for conductive pipes is actually better than for non-conductive as there are NO recorded incidents for conductive piping.
"There is a recurring cost of compliance when conductive systems are employed. Cenelec Code of practice CLC/TR50404, IEC 60079-32 and NFPA77 require the periodic testing of the earth connections through the whole length of piping when conductive lined pipe systems are employed. Third-party testing will be mandatory for licensing and insurance purposes.”"
The recurring cost to check compliance will be much higher for a non-conductive system! In a non-conductive system ALL bonding and earthing of metal objects in ALL chambers and in the proximity must be checked. Not only are these arrangements more likely to fail, they are many and very time consuming to check. The checking of conductive systems is quicker and easier.
For a length of conductive pipe the necessary check is reduced to the need to verify end-to-end continuity, which is a single simple measurement on a well-designed system. In contrast, the checking needed on a non-conductive system involves verifying the continuity of tens of minor items on every line: a much bigger task.
"Because fuel conductivity can falsify an annual test result, it will be necessary to drain, disconnect one end and gas-free every fuel line before its electrical continuity may be tested."
Fuel conductivity cannot falsify a test result. Product lines are always filled with fuel during operation so testing with fuel in the pipes is a valid continuity test.
"A non-conductive pipework system utilises material which naturally limits the amount of energy build up; no means to dissipate energy is necessary."
It is well known that very high static voltages can build-up on non-conductive materials. Non-conductive is the term for materials that lack ability to "naturally limit the amount of energy build-up". Non-conductive objects cannot be grounded to allow dissipation of static charges. This does however not mean that dissipation is not necessary or desirable, especially in flammable atmospheres.
"The use of non-conductive polyethylene fuel pipework for the transport of fuel underground does not constitute any increase in electrostatic hazard over metal pipework or artificailly conductive pipework."
This is wrong. The recorded incidents show that the risk with non-conductive pipework is worse than with metal pipework which is inherently free from static hazards and also worse than with conductive plastic pipework.