Petrol taps & pipes

All A, B, C and M pre unit models have a 3/8 BSP thread in the tank for the tap. Initially the tank end of the tap was without a filter and had a 1/8 BSP thread that screwed into an adaptor with a 3/8 BSP male thread and a filter. It was this that screwed into the tank. Later taps were fitted with a filter and had a 3/8 BSP thread and so dispensed with the adaptor.

Most taps had a 1/4 BSP threaded outlet and originally used a rigid copper pipe with soldered fittings. For a few years the A group used a spigot on the lower end of the tap and a ‘banjo’ fitting on the petrol pipe.

Where a tap, at the time of writing, is not available a suitable alternative is suggested, however as new items are being discovered all the time it would be wise to check the price list for current availability.

The sizes given with the taps listed are British Standard Pipe or BSP thread sizes, tank end is given first then the outlet. A tap with a 1/8 BSP thread will need the 27-8436 adaptor with filter or A16-96, a tap with a 1/4 BSP thread will need the A16-90 adaptor. BSP thread sizes are confusing because the size relates to the size of the pipe not the thread. Nominal thread sizes are as follows (male then female):- 1/8 BSP .375, 0.35; 3/16 BSP 0.425, 0.375; 1/4 BSP 0.515, 0.468; 3/8 BSP 0.650, 0.609. All sizes of threads are 19 TPI except the 1/8, which is 28.

This table shows the more popular applications.

Descriptive List of Available Taps and Fittings – Applications are listed below under model headings