Marelon Pipe to Hose Adapters
What Are Marelon Pipe to Hose Adapters?
Marelon pipe to hose adapters are specialized marine plumbing fittings designed to bridge the gap between threaded pipe connections and flexible hose runs aboard a boat. Whenever a rigid pipe system — such as one threaded into a seacock, raw water strainer, or marine pump — needs to transition to a flexible hose, a pipe-to-hose adapter provides the critical link. Without this fitting, it would be nearly impossible to create a leak-free, reliable connection between these two different plumbing formats.
The defining feature of fittings in this category is their Marelon construction. Marelon is a glass-reinforced composite material engineered specifically for the marine environment. Unlike traditional bronze or brass fittings, Marelon is fully corrosion-resistant — it will not corrode, dezincify, or react galvanically with other metals aboard the vessel. This makes it especially valuable below the waterline and in raw water systems where saltwater exposure is constant. Marelon fittings are also significantly lighter than metal alternatives, which can be meaningful on performance-oriented sailboats and powerboats alike.
Why Pipe to Hose Adapters Matter on Your Boat
Marine plumbing systems combine rigid pipe threads (typically NPT or BSPP) with flexible hose runs to accommodate engine vibration, hull flex, and the need to route plumbing around tight spaces. Pipe-to-hose adapters are the workhorses that make these hybrid systems possible. They are commonly used with seacocks, raw water intake strainers, bilge pump outlets, head systems, and livewell plumbing. Choosing the correct adapter ensures a secure, watertight seal and adequate hose seating area for double-clamping — a best practice in any below-waterline application.
When selecting a Marelon pipe to hose adapter, consider the pipe thread standard (NPT or BSPP), the nominal pipe size, the hose inner diameter you need to match, and whether a straight or angled (90-degree or 45-degree) configuration best suits your routing. Standard-flow fittings match pipe size to hose ID, while full-flow designs maintain unrestricted internal diameter for applications where maximum flow is a priority.
Top Brands in Marelon Pipe to Hose Adapters
Forespar is the originator and leading manufacturer of Marelon marine fittings. Forespar developed the Marelon composite specifically for marine plumbing, and their pipe-to-hose adapters are widely regarded as the benchmark for corrosion-free, lightweight performance in demanding onboard environments. Their fittings are available in a range of sizes and configurations to suit virtually any marine plumbing layout.
Groco is a marine hardware institution with a heritage going back over a century, known for precision-engineered pipe-to-hose fittings designed for use with seacocks, raw water strainers, and any application requiring a tapered female pipe thread connection. Groco offers fittings in multiple configurations — including straight, 90-degree, and full-flow designs — ensuring secure, reliable transitions from threaded pipe to flexible hose.