OhioRiverCigarett

I have a 1981 33 foot cigarette with "original" raw water strainers. I am not sure who made these, but they are brass with a clear plexiglass top and a single 3/8 bolt down through the top. I had to machine new plexiglass tops (1/2 in thickness).

How much pressure should it stand up to? Do you need to permitex the top in. It has a flat rubber gasket around the outer edge. It is leaking around the edge.

Thanks for any help