Delavan 1/8 long nozzle adapter 28738-001

The Delavan 1/8 long nozzle adapter (SKU 28738-001) is a reusable metal fitting that connects an oil nozzle to the fuel supply line inside an oil burner. It positions the nozzle securely within the combustion head, ensuring correct distance from the diffuser or blast tube. The adapter features a hex body and is designed for 1/8 inch thread size, typically BSP or NPT. It is not a consumable but a durable component that should be cleaned and replaced only if threads are worn or the sealing surface is scored.

Parts of this type are selected by matching the thread standard (typically 1/8 inch BSP or NPT) to both the nozzle and the oil pipe union. The 'long' designation refers to the overall length, which must correspond to the burner assembly geometry to position the nozzle correctly. Before ordering, verify the thread size and measure the required length against the original part. Inspect the sealing face and hex body for damage, as any defects can cause leaks or air ingress.

When such fittings fail, common issues include oil leaks or air ingress due to damaged sealing surfaces or worn threads. This can disrupt pump pressure and atomisation, leading to sooting or ignition delay. Check the adapter for scoring on the sealing face and thread wear, and replace if necessary.