Triumph Repair: Purpose and Operation of Flame Trap, flame trap, fuel vapors

Question
Greetings Howard,

My '75 TR6 has one flame trap installed between the bass of the front carb and the distributor vacuum port.  However, my rear carb tap is connected directly to the EGR valve despite the fact that all the books I look at show it requiring a flame trap.

What would be the impact of not having that flame trap and, furthremore, what is the purpose and operation of the flame trap in the carburetion process?

Thanks

Answer
Hi Nelson,
The trap is a fuel trap which you can call a flame trap as it is a bad idea the have fuel vapors condense in the hose and get into the diaphragm of the EGR valve even though there is no connection between the flames of the exhaust in the EGR valve and the diaphragm. The fuel vapors can condense in the hose and cause raw fuel to collect in any diaphragm so thus fuel traps. The heat around the EGR valve will probably keep any fuel that might migrate into the diaphragm vaporized and not cause a problem. I have seen many cars operate without the fuel trap. If you can locate one it would still be a good idea to put one on. It will not alter the operation of the valve with or without a trap.
Howard