Fuel dispensing - getting the metrics right

Whilst the specification for fuel management is usually very detailed, there is very little consideration given to fuel pump/dispensers.

Very often it is just an afterthought without any thought about performance and reliability of the pumps, according to Stephen Hannan, sales director of MIS Fuel Monitoring, a leading depot fuelling supplier.

“In fact the fuel pumps are essential to the overall fuel management strategy. So beware of such complacency – you are putting your reputation on the line.

“The consequences will be felt should the pumps break down due to overuse or when pumping accuracy deteriorates to a point when the company auditor/accountant can see that there are discrepancies in the reconciliation between delivery, consumption and stock balance.

“It is important that fleet operators scrutinise every component of the installation from the point of view of the operational requirement, performance and through life costs of ownership.

“The pumps are key to the availability of fuel and the accuracy of the monitoring facilities. No one is their right mind would risk everything by making this selection based on price alone.

“Don’t be fooled by stylish enclosures. It is what is under the covers that matters and some important questions need to be asked of the pump supplier in order to insure that that the equipment is up to the job. It is essential to specify exactly what the customer / operator expects from the pump/dispenser in terms of accuracy, ease of use and durability?

Each of these is summarised below.

Accuracy

How accurate do the readings need to be?

Factors to check out:

• Positive versus non positive displacement meters - only positive displacement meters measure every drop of fuel passing through the pump.
• Air Separation versus no air separation - only pumps with air separation can ensure that only actual product is metered and that any air within the product is removed prior to metering. Air held within the product is a variable that will lead to poor accuracy and worse still inconsistent accuracy that cannot be "tuned" out.
• What are the design tolerances for the meter?
• Above + or - 1% is poor and often unacceptable for auditors.
• Between + or - 0.5% and + or - 1% is satisfactory for lighter users.
• Between = and - 0% and + or - 0.25% is acceptable.
• Ask the OEM to state design accuracy and better still to warrant this accuracy over a known throughput.
• Good pumps will include a built in filter unit within the pump unit to protect the meter from dirt and other contamination.

Ease of use

• Some pumps use mechanical registers which require manual reset and are rarely lit. Better pumps feature illuminated electronic displays with auto-reset thus reducing pump wear and easing usage.
• Where vehicles fuel from both sides the meter flow should be visible from each side. Many Health and Safety officers are now insistent that fuelling personnel must be capable of observing what quantity of fuel is being delivered as it happens to avoid spillage.
• Length of hose is a major factor. Too short and they will be pulled and damaged. Too long and they will trail on the floor and become subject to excessive wear and being run over. They may also create trip hazards.
• Where longer hoses are used consideration should be given to using either a high hose mast assembly or even a retractable hose reel. Overhead swing arms are generally not recommended. The fitting of a hose safety break coupling is essential.

Durability

• Does the pump meet the operational requirements in terms of reliability and quality performance of the fuel delivery components.
• What is the design standard for the pump unit and motor?
• What does the original equipment manufacturer state is the expected lifetime and usage limits.
• How powerful is the pump motor? Will it stand up to the type or pattern of throughput?
• How are the frame and panels constructed, does the OEM offer any specific bodywork warranty?
• What is the quality and specification of the hose and nozzle – the most used parts of the dispenser.