Oil Heating Accessories - Tank Accessories This is an important section of our product range for some 40 years. Whatever your requirements, our system components cover most pipeline accessories required for any fuel or heating system installation, from tank vent-caps to boiler safety components. Air supply dampers for boiler room air control and stabilisers for regulating chimney draughts are also available. You can rely on our experience. If you need any assistance please click here to contact us or call us on the number above. Product Name Application Image Leaflet Download Filler Cap A basic cap to fit on a fuel tank. Versions are available in grey ABS plastic and brass; the latter has a fitting for use of a padlock. Both models are 2"BSP.   - Further Info. Vent Cap  A drop-down type vent cap moulded in grey ABS plastic available in 1 ½" and 2" BSP.   - Further Info.  Combivent As the vent cap, but provided with 1 ½" BSP tread to accommodate the Afriso MTF 500 float gauge.  - Further Info.