Used for some through hull fittings under the waterline on Catalinas built after the mid 80's. Used for some head sink drain valves, engine raw water intake valves, or salt water hand pump intake valves. They are impervious to rust and corrosion and are now used as standard equipment by many of the world's largest boat builders.
It is important to replace the garden variety bronze gate valves used in early Catalinas. Have your boat surveyed by a qualified marine surveyor. Without exception the report you receive will list the bronze pipe nipple "through hulls" and gate valves as must replace.
The nipples are glued to the hull with the same polyester resin used to build the boat. Polyester resin is a good boat building material but not a strong adhesive. Replace the bronze nipples with real through hull fittings. See the related items below for replacement fittings.
Molded Marelon offers superior strength and corrosion resistance. Marelon is lightweight, corrosion and electrolysis free, ideal for thru-hull valves. Marelon is a modern material formulation of polymer composite compounds that uses resins and additives to produce an extremely strong marine-grade product that will not deteriorate like traditional bronze marine plumbing parts.
National Pipe Straight Mechanical (NPSM) threads used in marine fluid systems that requires thread compound or Teflon tape to seal. The female component incorporates a straight, non-tapered thread with an inverted 30° chamfer of the male connector on the seat of the female. This is a mechanical seal.
• Thread type: 1/2" National Pipe Straight Mechanical
• Body diameter: 1-7/8"
• Body length: 3"
• Overall length (including handle): 4"