The carpenters came up with the stairs for kids idea, Slim. My knuckle dragger mind did notta thunk it.
The Triumph has a tank vent valve and a tipover valve from the factory. They have enough capacity for the standard bike or a moderately hopped up one, plus, the tipover valve is plastic. There might not be enough flow capacity for what I am doing and I want metal fire resistant ones.
These are metal valves made by Newton in London
www.newtn-equipment.com They are small and just right for a bike although some are recommended for F1. They were bought from Fuel Safe here in America
www.fuelsafe.comThe little guy is a TRL7 in-line tipover valve. Air can be pulled into the system through it or expelled out if the valve is nearly vertical. The valve shuts if it is tipped to the side and liquid tries to pass out through it. This will keep fuel from flowing out of the vent in a tipover.
The big fellow is a TPV8 tank vent pressure release valve. It allows air to go into the tank if internal pressure drops down to less than 0.08 psi below atmospheric. This lets air in as the fuel level drops or the fuel cools and shrinks. The valve lets vapor out if the tank pressure is more than 0.725 psi above atmospheric. This keeps the fumes in the tank and it releases them if there is substantial internal pressure, only.
There is some debate if a gravity flow fuel system should pull against any valve, even one as soft as this. The tank vent valve will be bypassed during racing. The vent will be open to the atmosphere. ERC recommends this.