Forespar® "93" series of valves and thru-hull fittings meet all design criteria and exceed all mechanical property requirements specified by the international standards organization (ISO 150/188) "small craft-seacocks and thru-hull fittings-part 2: Non-metallic"
Exceeding ABYC recommendations and meeting all UL standards; its unique design provides easy installation in a wide variety of valve configurations. It allows the OEM to design systems never before possible. All Marelon ® integrated valves are sold as a complete system. The assembly consists of thru-hull, valve body and tailpipe barb or female pipe thread end. The thru-hulls use a buttress style thread for exceptional strength and are not compatible with any other valves. Thru-hulls cannot be sold or used separately. All valves have one part number for the complete assembly. Each valve is factory assembled and pressure tested. Forespar ® cannot be responsible for valves dissembled and modified or reassembled improperly.
In case of an emergency, all non-screened thru-hull style valves are supplied with a handle cap/plug that is designed to plug the thru-hull from the outside. The plug can be put in place while the vessel is in the water. The valve can then be removed from the king-nut and any blockage cleared. Warning - Never leave a boat unattended while plug is in place and valve is dissembled. The plug is for temporary use only. The plug can also be used during winter storage to keep debris from collecting or insects from nesting inside thru-hull.
Per ABYC/UL requirements, a flat surface approximately the same diameter as the king-nut is needed inside the hull for proper installation. Al valves are full port. The I.D. of the hose barb is carried thru the ball so there is no restriction of flow.
General Note: Forespar threaded plumbing fittings (like most true marine plumbing fittings) use NPSM Threads - National Standard Free-Fitting Straight Mechanical Pipe Thread. NPT - National Pipe Threads are tapered, NPSM Threads are parallel. The two types are not designed to work together.