Meter Seal Requirements

By Richard Fredenburg… We wear two hats when it comes to propane inspections. Most of the time you’ll see me writing about propane safety, but we also have a responsibility for propane weights and measures. While many states, probably most, have these responsibilities in different agencies, we like the way we do it in North Carolina.

Sometimes weights and measures rules bump up against safety rules. Notice I said “bump.” I did not say conflict. One place where this happens is filling cylinders. We allow dealers to charge a flat fee for filling a cylinder and we expect it to have the full legal amount when the customer leaves with it. We also expect it to not be overfilled. That places a burden on the dealer to fill a cylinder to, but not above, the 80% level. We’re talking a fine line, here. That takes some attention to detail.

Our calibrations and sealing are in accordance with the National Institute of Standards and Technology Handbook 44, Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices. We call it NIST Handbook 44. We adopt it by reference, as do almost all other states. We also take a few exceptions to it, as do some others. Therefore, what I say in this article may not correlate exactly with your state.

Some of our inspectors calibrate meters on bobtails and on dispensers. When they finish, they attach a wire with a metal seal that makes it difficult to impossible to tamper with the calibration settings without violating (breaking) the seal. There are also private companies calibrating meters that provide their own seal to prevent undetected tampering with the meter settings.

We noticed a couple of years ago that the rate of broken seals being found on meters was increasing. While we weren’t finding evidence of tampering with the calibration, the broken-seals trend was troubling. Each broken seal means that there could have been intent to defraud the customer on each delivery. That’s why NIST Handbook 44 and state law requires a seal to be in place on any meter where the selling price is based on the meter reading. Further, our state law has a provision that, if a meter “…is inaccurate and the seal broken, [it] shall constitute prima facie evidence of intent to defraud…” That should eliminate any doubt of our seriousness about keeping seals intact.

We know that seals are going to get broken for legitimate reasons. We made plans for that and will authorize a dealer to break a seal, fix what is wrong that doesn’t affect calibration, apply their seal, and send us a seal break report. Things can happen, such as a ticket getting stuck in the printer, glass dirty enough that the numbers can’t be read, a gear slipping out of alignment, mounting studs getting loose, etc. Sometimes a wire can get snagged with a tool or cuff button. No need calling us to reseal it when a dealer’s employee can describe the non-calibration-affecting reason for breaking the seal, reseal it with a seal that identifies them, and allow it to go back into service. We call them a Limited Petroleum Device Technician. It’s a derivative of the Petroleum Device Technician License that allows the holder to perform calibrations.

The limited license is not a blanket approval for all fixes. No changes to the temperature compensator are allowed, including turning it off or on. Neither are changes from one type of register to another, changing the gear train, replacing a broken gear, and a host of other changes.

Sometimes the manufacturer ships a new meter with factory seals in place. Do not understand this as indicating any type of calibration has been performed—these seals are there to protect the equipment during shipping and handling. A meter cannot be accurately calibrated until it is installed into the piping system where it will operate. Differences in flow characteristics of piping leading to and away from the measuring chamber affect how it responds. Besides, there is an NIST Handbook 44 requirement that the meter be installed before calibrating it.

We had a situation where a dealer wanted the dispensers it was supplying to a couple of stores calibrated and sealed before they were set so the customers could start using the meter immediately. The dealer shipped the meters to a prover-equipped company and asked them to calibrate the meters bare, not installed in a dispenser system. The company dutifully sent me calibration (placed in service) reports. I noticed that the flowrates were high for dispenser meters. A call confirmed that the meters were calibrated 1) not in the system where they will be used, and 2) at a flowrate outside of their specifications. I rejected the calibration reports. The dealer agreed to ship the assembled dispenser system to the Petroleum Device Technician for calibration.

There are many “what if” scenarios for when an inspector finds a meter without the required seals. They are too numerous to go through here, and your state may not treat them as we do. We give a warning before assessing a penalty, but it doesn’t take long to exceed the grace count if the supplier has many dispensers where it owns the equipment or if it operates several trucks.

Seals are used to protect customers from fraud. We also hear that dealers want them in place to ensure their employees don’t steal from the company. Monitoring the status of your seals and making sure all metered sales are based on properly-sealed meters is a win-win situation for customers and for dealers.

Richard Fredenburg is an LP-gas engineer with the North Carolina Department of Agriculture and Consumer Services.