This is the PWC section... so they aren't going to know. I'll move it to the boat section for you. But, I'm unsure what you are asking. A ball scupper has a rubber seal, cup, and a ball. The seal normally doesn't have anything making it a unidirectional part. Can you post a pic?
I'm assuming you mean part nbr 23 in the pic below. It doesn't show any differences in the sides as to which way to position. Being that that the through hull fitting is where it's sealed, I'm not sure positioning matters.
I agree with Dr. Honda, post a pic of the part in question so we can see what you're referring to.
I assume he means the tapered seal that gets sandwiched between the boat hull and the plastic scupper housing. The tapered part is what the ball seals against, so it faces out when installing it.
This is the PWC section... so they aren't going to know. I'll move it to the boat section for you. But, I'm unsure what you are asking. A ball scupper has a rubber seal, cup, and a ball. The seal normally doesn't have anything making it a unidirectional part. Can you post a pic?
I assume he means the tapered seal that gets sandwiched between the boat hull and the plastic scupper housing. The tapered part is what the ball seals against, so it faces out when installing it.