Any Metallurgy Engineers?

[Skywagon]

Non-bike related so hang up if not interested

I want to mill a pipe that is roughly 12 inches long and about 3/4 inch in circumference . I will drill two separate non connecting holes the full length, and drill and tap for my need. One side will carry low pressure water and the other side gasoline low pressure 
 

This questions is where I need help. The inside water jacket will have salt water flowing through it continuously while in operation. It could be idle for a couple of weeks with no flow of water. I’m looking for the right material for that environment that will minimize corrosion and salt water plugging up

The existing aluminum (not sure of grade like 304) will plug up with salt, sand, etc after a while causing the fuel to not be cooled properly and creating vapor lock or other sensors to engage a problem alarm/shutdown

 

Im looking at tungsten but have no experience with it. I’m a nut and bolt guy not an engineer. 
 

Thanks if you have advice

 

[Joe Frickin' Friday]

Naval brass?

[MachineJoe]

If you are truly using aluminum I could see where the corrosion could happen and have sand and salt start to dam things up

The 304 that you're referring to sounds more like a stainless steel grade. I don't believe it would be aluminum.

 

A less corrosive grade of stainless would be 316 - (considered marine grade)

https://www.mcmaster.com/metals/stainless-steel/shape~round-tube/

 

I'm not a real metallurgist, but I did play one on TV

[Skywagon]

Thanks guys.... MJoe...I'm not sure of the exact material.  Mitch....hmmm.. that seems worth a try.  I don't think this piece will be in contact with any other metal so probably that will work.  I'll try some 316 and MIL Brass and see what happens.  

[TSConver]

316 SS for Marine use.  Titanium but that is hard to mill.

[Rougarou]

Beryllium copper

[LBump]

Would HDPE pipe work for you application?

[ESokoloff]

1 hour ago, LBump said:

Would HDPE pipe work for you application?

Plastic won’t transfer heat well. 
 

https://www.sciencedirect.com/topics/engineering/thermal-conductivity-coefficient

 

[realshelby]

Stay away from titanium. 304 Stainless would probably be just fine and is easier to find. 316 Stainless is a higher grade and better corrosion properties. Can still be machined fairly easy. ( Both can ). Sounds like you want round bar, not pipe ( pipe is hollow ). Online Metals is where I get most of the material I machine for parts. 

Drilling side by side holes through a 3/4" x 12" bar will have some challenges. Could you use something like 1/2" hex bar 316 stainless and drill a 1/4" hole through the center of two pieces of that? Then weld them together? I assume you are wanting to heat or cool the gasoline? 

 

Link to 316 hex bar:  https://www.onlinemetals.com/en/buy/stainless-steel-hex-bar-316-cold-finish

[Skywagon]

Thanks Terry. Yes not pipe. It is to cool gasoline inside a hot engine compartment. There is an existing factory part so not just trying to make up a fix for something. The fix I am trying to do is find a metal that doesn’t fill up with salt water, corrosion, and block water flow causing the gas to create a vapor lock situation when hot with stop and start

 

The existing part is sealed on both ends. When it clogs you buy a new one and spend 3-4 hours changing out. AMHIK. My thought is to make one with the best resistance metal, and tap both ends with a flush part. It might be over my head but  I want to give it a try. Heck there might even be a small market for it

[realshelby]

The hard part in what you describe will be drilling the holes. Over 6 inches from each side and another set parallell. Takes some precision drilling for that, along with precision setup on the parts. 

If the smaller hex bar welded side by side would fit, we could chuck the bar up in the lathe and drill from both sides down the center. But if that don't fit....

[ESokoloff]

On 12/13/2021 at 7:32 AM, Skywagon said:

The existing aluminum

If using a material different then original you will have to make allowances for proper heat transfer. 
 

Copper alloy looks to be a good compromise between material resistance/durability & heat transfer ability. 
 

McMaster Carr offered Copper-Nickel 

Pipe Fittings

 

https://www.mcmaster.com/Standard-Pipe-Fittings/copper-nickel-unthreaded-pipe/copper-nickel-pipe-and-pipe-fittings

 

perhaps worth considering.