[peva]

I see this note on their silicone hose pages:

Note: This hose is NOT formulated for use in oil or fuel plumbing applications. It will handle an air-fuel mixture and will survive occasional spills and oil leaks, but it will not stand up to continuous exposure to liquid petroleum.

I'd have to try it to see, but have my doubts that it would last in the hot and caustic crankcase blowby gas and oil and their condensates PCV environment.

In what experimenting I did, I concluded that hoses for use in PCV use had to be formulated for that purpose. While silicone is the absolute best for coolant and, from my personal experience, very hot coolant (like turbo coolant outlet hose) applications, I don't know what the correct rubber formulations are for PCV, but I know that no hoses designated tor coolant that I tried held up for any length of time for PCV use.

EDIT: On looking at this page on Summit Racing: PCV Hoses and Tubes - Free Shipping on Orders Over $99 at Summit Racing
I see neoprene (Buna-N) mentioned in some of the descriptions. I guess that is the "secret" ingredient. And no doubt there are specific formulations of that that hold up better than others. I wonder how Viton would do.

 

[peva]

(It won't let me edit that post again)

It seems that Viton is better than neoprene for higher temperature and most fuel and oil applications until you get below 5°F (may be OK for low pressure PCV hoses in cold temperatures?): What's the Difference Between Buna vs Viton O-rings?

 

[polmanter74]

so while i was removing the inner tie rods from the rack, i think this hose busted because i pushed on it too hard or something? im not sure, but it looks like it might be a vacuum line (?)
is there any chance youd know what that is and how to repair it?
View attachment 42095

(It won't let me edit that post again)

It seems that Viton is better than neoprene for higher temperature and most fuel and oil applications until you get below 5°F (may be OK for low pressure PCV hoses in cold temperatures?): What's the Difference Between Buna vs Viton O-rings?

There is also a kinda silicone hose that does hold up oil I can't remember the name but it starts with an F, but it is very expensive like $70 a foot. This picture above looks like the exact one that was on my pvc valve before I upgraded, I don't know what material it was made of since it's a factory . But I completely removed mine and put in a oil catch can

 

[peva]

View attachment 42188 View attachment 42188

There is also a kinda silicone hose that does hold up oil I can't remember the name but it starts with an F, but it is very expensive like $70 a foot. This picture above looks like the exact one that was on my pvc valve before I upgraded, I don't know what material it was made of since it's a factory . But I completely removed mine and put in a oil catch can

Perhaps they use silicone for the main wall thickness for the bulk mechanical support and temperature resistance but have a smaller thickness liner material that is maybe more expensive per volume but has better resistance to the harsher chemicals

 

[polmanter74]

Perhaps they use silicone for the main wall thickness for the bulk mechanical support and temperature resistance but have a smaller thickness liner material that is maybe more expensive per volume but has better resistance to the harsher chemicals

 

[polmanter74]

Perhaps they use silicone for the main wall thickness for the bulk mechanical support and temperature resistance but have a smaller thickness liner material that is maybe more expensive per volume but has better resistance to the harsher chemicals

It's like this, this is a blue silicone radiator hose, but the ones needed for oil resistance look the same but are made of a different kinda silicone

 

[peva]

I've used the blue silicone before (NAPA carries it). Another brand I've used has a pastel green outer material (maybe it's NAPA that carries the green - I forget - but the blue is real purty!). I'm guessing the silicone is the red interior. The blue covering is probably some other material to prevent clamps from cutting the relatively soft silicone and possibly resist attacks of certain chemicals (petroleum products?) that it might be exposed to in the working environment (car engine compartment or whatever).

I've read that plain silicone hose is somewhat permeable to water, resulting in coolant loss over time, so the outer covering maybe also helps reduce water/coolant loss?

Would be interested to know about the silicone hose for petroleum - if a special formulation of silicone is used for the inner lining or if it's something else.

https://whdcanada.com/wp-content/uploads/2020/04/master-assembly-catalog.pdf

 

[polmanter74]

I've used the blue silicone before (NAPA carries it). Another brand I've used has a pastel green outer material (maybe it's NAPA that carries the green - I forget - but the blue is real purty!). I'm guessing the silicone is the red interior. The blue covering is probably some other material to prevent clamps from cutting the relatively soft silicone and possibly resist attacks of certain chemicals (petroleum products?) that it might be exposed to in the working environment (car engine compartment or whatever).

I've read that plain silicone hose is somewhat permeable to water, resulting in coolant loss over time, so the outer covering maybe also helps reduce water/coolant loss?

Would be interested to know about the silicone hose for petroleum - if a special formulation of silicone is used for the inner lining or if it's something else.

Actually both layers are silicone, the blue is just a color for to make your application look custom, it comes in many colors, you can replace any hose or vacuum line on your car with silicone hose, but since the pvc valve has oil in it you need a special kind its called Fluorosilicone. It's the only silicone you can use for a pvc system because it's more oil resistant