These Seacocks are designed for thru-hull applications and are typically characterized by a mounting flange which helps distribute the side-load when the handle is turned. The MF 849 Flanged Seacock Series has NPS straight (aka parallel) threads at each end, and is designed to be fitted with straight thread thru-hull fittings and straight thread tail pieces.
Straight threads are not "self-sealing". You must use pipe joint compound, thread seal compounds, or "Teflon tape" to seal the threads when making connections.
The advantage of parallel threads over tapered threads, however, is that there is maximum engagement between the mating threads providing an especially strong connection.
These seacock assemblies are made of exceptionally strong, fiberglass-reinforced Marelon. Marelon is both electrically and chemically inactive - making for easy installation, very low maintenance, and long service life for the end user, without the worry of possible corrosion over time. It is very light weight, has exceptional UV resistance, and will not freeze or become brittle with age.
Marelon exceeds ISO standards, is approved by the ABYC, and passes the same stringent Marine UL tests as bronze.
• Lightweight, yet extremely strong injection-molded parts
• For use above or below the waterline
• NPT parallel (straight) threads
• Completely free from electrolysis or reaction to any metals - no electrical bonding required
• Completely free from any corrosion
• Minimal maintenance requirements - requires periodic lubrication
• Accepts adhesives and coatings (bottom paint) easily
• Can be used on aluminum, steel, wood, or fiberglass hulls
• Can be used with metal fittings
• Long term reliability