Collection: Speedflow Filler Caps & Weld Bung Assemblies

Browse Speedflow filler cap and weld bung assemblies for custom tank and filler fabrication, plus a separately sold replacement cap. Select by bung bore, weld-neck material and exact part number.

Listed assemblies

• 1-inch bore: aluminium 460-16 cap and bung assembly.
• 1.5-inch bore: raw aluminium 460-24, black-cap aluminium 460-24-BLK, and stainless steel weld-neck version 460-24-SS-BLK with a black aluminium cap.
• 2-inch bore: aluminium 460-32, black-cap aluminium 460-32-BLK, and stainless steel weld-neck version 460-32-SS-BLK with a black aluminium cap.

The bore measurement refers to the bung's internal diameter, not the cap's outside diameter or thread size. The assemblies use matching threaded caps and bungs; listings describe female-threaded caps with O-ring seals and finger grips.

Replacement cap

C4600-24-BLK is a black anodised aluminium replacement cap listed to suit the Speedflow 460-24 weld-on filler neck. It is sold individually, not as a cap-and-bung assembly. Confirm the exact neck and cap compatibility before ordering.

Selection and fabrication

Match the weld-neck material to the component being fabricated and check the neck dimensions, cap clearance and filling access. Do not assume a stainless steel weld-neck assembly has a stainless steel cap.

Confirm cap and O-ring compatibility with the intended fluid, temperature and operating conditions. Check venting requirements separately rather than assuming the cap provides tank ventilation, pressure relief or a coolant pressure-cap function.

Have welding carried out by a suitably qualified fabricator using the appropriate process and filler for the materials. Follow the manufacturer's installation guidance and inspect and test the completed assembly before use.