Reusable fittings
Reusable fittings are among the most common in Fast Road, track and many race cars. They offer greater clamping force than standard fittings, therefore aid reliability on high performance engines, and in many circumstances allow better routing of the hose to give a neater installation than the standard set-up.
They also allow the end user to create their own hoses, as the reusable fittings don’t require specialist tooling.
An anodised aluminium spanner can be bought to be used with the fittings, and as this has the same material hardness as the fitting it won’t chip or damage it in the way a conventional spanner could.
They work by effectively squeezing the hose on to the fitting. The red nut sleeves over the hose and screws to the blue part of the fitting. In doing so the rubber hose is squeezed into a machined edge within the fitting, which creates a tight seal. The other end of the fitting (usually female) is then screwed to the relevant component, such as the fuel pump.
The fittings for PTFE hose work in a similar way, but given the hardness of the PTFE material have to be slightly different. The silver nut sleeves over the hose, but rather than squeezing the hose into a machined edge in the fitting. The fitting acts more like a thread with the PTFE effectively pinched between the outer nut and the main body of the fitting.
This type of fitting can only be used on the smooth bore PTFE hose, as the fully convoluted hose would have potential leak paths due to the uneven nature of the hose’s bore. For use with fully convoluted hose a fixed draw swage fitting is required.