copper fuel pipe?

[dmorley]

I just pulled up Title 46 sec. 56.50-70 of the Code of Federal Regulations and it states, "(a) Material. (1) Fuel supply piping to the engines shall be of seamless drawn annealed copper pipe or tubing, nickel copper, or copper nickel pip or tubing meeting the requirements of subpart 56.60" Basically a 3/8 diameter line needs to have walls .035 thick. Given I need to make a custom fuel line and copper is easy to work with, can anybody think of a disadvantage to using copper?<br /><br />Also, the same document states, "(2) A short length of suitable metallic or nonmetallic flexible tubing or hose, or a loop of annealed copper tubing shall be installed in the fuel supply line at or near the engine to prevent damage by vibration." Is this a new requirement and if so is the Coast Guard olding older boats to this spec? I know my original fuel line was one piece.

 

[rodbolt]

Re: copper fuel pipe?

hello<br /> what they are trying to tell you is the use of a seamless non corrodeing tubing. annealed copper is softer and less prone to cracking. all flares for tubing fittings should be a double flare although its no required. the section wher the fuel line goes from the bracket on the stringer to the engine either has to have at least one coil or be a non-metallic flexable line. if your ran a line from the stringer straight over to the engine it would jerk it and cause a leak.<br /> you can also use rubber lines for gasoline just look up the specs for that, diesel and kerosene fuels reqire a different rubber than gas.<br />good luck and I hope all is clear now

 

[dmorley]

Re: copper fuel pipe?

Rodbolt,<br />What is a double flar? Also, with my setup the solid fuel line comes from the fuel pump which is mounted on the engine and therefore should move with it. You are right, however, if it came from a stringer or some other point external to the motor.

 

[rodbolt]

Re: copper fuel pipe?

from the pump to the carb or injector rail MUST be a solid mettalic line. the suction lines can be either. a double flare is what is used on brake lines. it allows more stress to be carried without the flare splitting.<br /> good luck and keep posting

 

[rodbolt]

Re: copper fuel pipe?

hello<br /> let mee modify the solid part. some manufacures are using a double braid rubber with a mettalic cover sheath. while the coast gaurd allows it it tends to be short lived. the regs can get confusing cause you have to know what your looking for and which section to look in. most the regs are more than 50-60 years old and some go bake to the teens and 20';s.<br /> good luck and keep posting