For a mobile flare, the spare parts worth holding are the ones whose failure stops the flare or makes it unsafe to run: the blower, the main gas valve, the flame detection devices and the ignition parts. A spares quotation for a mobile flare in Australia grouped its items into exactly those categories, and the structure is a useful checklist for any operator.

The challenge: remote sites and long lead times

A flare that stops can mean gas venting unburned, a breach of permit conditions or a site that has to shut down. For equipment shipped to Australia, the quotation allowed five to six weeks to make the parts in the UK, then one to three weeks by air or seven to nine weeks by sea. A spare that is on the shelf saves months compared with a part ordered after a failure.

The approach: grouping spares by function

The spares list for the mobile flare was organised into four groups.

Critical

• Blower and inverter, as a set. The blower moves the gas to the flare. If it fails, the flare cannot burn anything. The inverter varies the blower speed, so the two are best held together.
• Main gas valve. The valve that opens to feed gas to the burner and closes in a fault.

Safety

• UV eye. The sensor that detects ultraviolet light from the flame, telling the controller the flame is alight.
• Flame watcher. A further flame monitoring device.
• Pressure switch. Monitors pressure in the gas line.

Ignition

• Ignition transformer. It raises the voltage to create the spark.
• Ignition electrode. It carries the spark to the pilot or burner and is exposed to heat.

Control and monitoring

• Orifice plate differential pressure transmitter. It measures gas flow.
• Suction transmitter. It measures pressure at the blower inlet.

The same pattern elsewhere

A separate spares enquiry for an enclosed flare in North Africa followed the same logic. It covered a gas valve with a motorised actuator, an ignition electrode, an ignition transformer, a UV sensor and a thermocouple. The valve had a lead time of eight to ten weeks from the UK, while the electrical items took seven to ten days. The valve is a good example of a long-lead item that should be held in stock.

The supplier also noted that, with the information given, it had made assumptions, and that the end user must check the parts are compatible with the existing equipment. For older flares, send the serial number and photographs of the nameplate.

Why it works

Groupings turn a long parts list into decisions. The critical items would stop the flare. The safety items would stop it or make running it unsafe: if the flame detector fails, the controller cannot confirm the flame, so the flare shuts down to protect itself. The ignition items wear out through use. The control items would not stop the flare but would leave the operator blind to flow and pressure.

What to consider for your own project

1. Rank by consequence of failure, not by price.
2. Check lead times. Ask which items take more than a few weeks and hold those.
3. Hold a wear kit. Ignition electrodes, UV bulbs and thermocouples are the parts most often replaced.
4. Keep the serial number and drawings. They save time when ordering.
5. Plan the freight route. Air freight is faster but costs more than sea. Decide in advance which you will use in an emergency.

For the UK context, see the Environment Agency’s guidance on managing landfill gas. For the flare itself, see our post on mobile open flare for low-methane landfill gas.

FAQ

What spares should I keep for a landfill gas flare?

Start with the blower, the main gas valve, the flame detector, the pressure switch and the ignition parts.

What is a UV eye?

It is a sensor that detects ultraviolet light from the flame and tells the controller the flame is lit.

Why is the main gas valve a critical spare?

It controls whether gas reaches the burner and must close in a fault. Without it the flare cannot run.

How long do spares take to arrive?

In these examples, from a few days for electrical items to eight to ten weeks for a motorised valve, plus shipping.

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