Petcock fuel line nipple

Is there supposed to be an o-ring on here?
When I got the motorcycle the nipple for the fuel line that slides into the petcock had been pulled out of the petcock body. I've read some posts that are discussing these nipples saying they just press back in there but this one appears to have a slot for an o-ring. So is there supposed to be an o-ring here or does that channel lock into something up inside the petcock body? Thanks . Also, should this nipple be oriented pointing directly down?

 

Nope, no o-ring.....those nipples are really a press-fit into the petcock body.

 

Thanks I guess they just put that groove in there to mess with us

 

I had similar with a brass nipple pulling out of a pot-metal petcock body. 40 years of exposure had got into the interface that was supposed to be a close push-fit, resulting in corrosion which had no grip on the brass.
Solution was a smear of epoxy about ten years ago.

 

Yeah I bought some "seal-all" yesterday just in case. I'm going to put some of that on there and Hopefully shouldn't have to worry about it coming out ever again. I've been leak testing it for 24 hours and so far so good, but I'm definitely going to add the seal-all still yet cuz I don't want it coming out of there and pouring gas everywhere unexpectedly

 

I was having a problem with the nipple coming out when pulling the fuel line off. A little loctite fixed that.