RV Parts and Plumbing Supplies

Start with the system: water, waste, power or climate

This aisle is organized by the system you are working on. Fresh-water parts include pipe, fittings, valves and pumps; waste parts are drains, traps and strainers; the rest cover lighting, ventilation and heating, power and electrical items, and interior fittings. Decide which system the part belongs to before you pick a size, because the same thread or diameter appears in several systems and the pressure, temperature and material needs differ. Drinking-water parts should be marked suitable for potable water.

Waste lines are the usual starting point for repairs. Match the nominal pipe size of the fitting to the pipe, and remember that sizes are names rather than measurements: a 3 inch pipe does not measure 3 inches across. Traps in several pipe sizes are listed under drain stoppers, strainers and traps.

Thread, press or glue: how the parts join

Check how a fitting connects before its size. Tapered NPT threads seal with tape or paste, while garden-hose GHT threads are straight and seal against a rubber washer, so a 3/4 inch hose thread will not screw tightly onto a 3/4 inch pipe thread. Press fittings need the maker's press tool and jaws, and solvent-cement joints are permanent. Thread adapters and clamps are gathered under hose fittings, adapters and clamps.

Material is the second check. Brass and stainless steel suit hot and drinking water, PVC suits cold lines and drains, and malleable iron or galvanized steel belong to heavier industrial pipework. Mixing dissimilar metals in a wet joint can corrode it, and plastics soften with heat, so check the temperature rating for water-heater and hot-water runs.

Questions about RV Parts and Plumbing Supplies

What is the difference between NPT and GHT threads?

NPT is a tapered pipe thread that seals by wedging and needs tape or paste. GHT is the straight thread on garden hoses and many RV water inlets, sealed by a flat washer. They look similar at the same nominal size but should not be forced together.

Is every part in this aisle safe for drinking-water lines?

No. Look for a mention of potable or drinking-water use, or a lead-free marking, in the description. Parts meant for drains, compressed air or industrial fluids may contain materials that you would not want in a fresh-water line.

How do I size a replacement fitting?

Identify the connection type first, then measure the pipe's outside diameter or read the nominal size marked on the old fitting. Note male or female ends, the thread standard and the pressure rating. If the markings are worn, compare the old part against a thread gauge or a ruler.