Nipple Fittings

A pipe nipple is the short threaded connector that ties your pump, unloader, coil, and plumbing together, and the right one costs a couple bucks while the wrong one strips out at 4,000 PSI. Sun Brite Supply carries nipple fittings in steel, brass, stainless, and poly, from 1/8 inch close nipples to BSP outlet and bypass nipples for hot water machines. Not sure if your machine needs NPT or BSP? Call 301-519-9274 and read us the numbers stamped on the old part.

How to Pick the Right Nipple Fitting

Three questions sort out almost every nipple fitting purchase: what thread, what material, and what length. Get all three right and the joint outlives the machine. Miss one and you get leaks, galled threads, or a fitting that rusts solid before the next rebuild.

Nipple Types Explained

A close nipple is threaded end to end with no bare pipe in the middle. It puts two fittings almost face to face, which keeps manifolds compact, but there is nothing to grab with a wrench, so removal takes an internal nipple wrench or a sacrifice. A hex nipple adds a wrench flat in the center, and on a pressure washer that hex is worth paying for every time. Standard pipe nipples come in set lengths, measured thread tip to thread tip, and give you spacing where you need it. Reducing nipples step between sizes, like 3/8 to 1/4, in one part instead of a bushing stack. Hose nipples have threads on one end and a barb on the other for clamped low pressure lines like bypass and chemical feeds. Bypass nipples, like the K7 series we carry for hot water skids, route unloader bypass water back where it belongs and are machine-specific parts, so match the part number.

Steel, Brass, Stainless, or Poly

Plated steel is the workhorse for high pressure lines. Our steel hex nipples are rated for the outlet side of a pressure washer, with some rated to 5,000 PSI, and they shrug off the torque a gorilla with a pipe wrench puts on them. Brass will not rust and machines nicely, so it is the pick for water inlets, chemical paths, and anything that sits wet, but keep it on the low pressure side of the pump on bigger machines. Stainless costs the most and earns it around softwash chemicals and salt air. Poly is for chemical suction lines only, never pressure. One more rule from the corrosion books: threading bare steel into brass in a wet system sets up galvanic corrosion, and the joint you saved two dollars on becomes the joint you cut out with a sawzall.

NPT, BSP, and JIC Threads

American machines use NPT, a tapered thread that seals as it wedges tight with sealant. Many pumps and unloaders built in Italy or Germany use BSP, which has a different thread angle and pitch. The two look similar and will even start together, then leak forever and ruin both parts. If your pump is a European brand, assume BSP on the ports until proven otherwise. That is why we stock 3/8 BSP outlet nipples alongside the NPT lineup. JIC nipples seal on a 37 degree flare cone instead of the threads, which makes them reusable and leak-free without sealant, and you will find them on better-built skids.

Nipple Fittings by Type and Price

Most of these are special-order or counter items that come and go, so call ahead to confirm availability on the exact size you need.

From the Field

The nipples that come across this counter cut in half tell the same two stories. Story one is rust. A plated steel nipple buried in a wet manifold for three seasons welds itself in place, and the repair that should have taken ten minutes takes an afternoon. If a nipple lives somewhere damp and low pressure, spend the extra dollar on brass. Story two is thread damage from reusing sealant-caked fittings. Old tape and pipe dope hide cracked threads and shed debris into your unloader. At one to four dollars a nipple, replace it during a rebuild instead of reinstalling a questionable one. And keep a spare high pressure hex nipple in the truck box. It is the part that fails at 7 am on a Saturday when every supply house is closed.

Related Collections

• Close nipples
• Steel pipe fittings
• Brass pipe fittings
• Stainless steel pipe fittings
• Polypropylene fittings
• Hex bushings
• Hex couplers
• Hose barbs
• 90 degree elbows and tees
• All fittings, or visit our Gaithersburg store

Frequently Asked Questions

What is a nipple fitting?

It is a short pipe section with male threads on both ends, used to join two female-threaded fittings or ports. Length is measured end to end, including the threads.

What is the difference between a close nipple and a hex nipple?

A close nipple is threaded its full length with no gripping surface, so it packs fittings tight together. A hex nipple has a wrench flat in the middle, which makes installation and removal far easier.

How do I know if my pressure washer pump uses NPT or BSP threads?

Check the brand. Italian and German pumps and unloaders usually run BSP ports, American equipment runs NPT. The threads look alike but do not seal together, so verify before you buy.

Can a steel nipple handle 4,000 PSI?

High pressure rated steel nipples can, and some we carry are rated to 5,000 PSI. Standard plumbing-grade nipples cannot. Check the rating on the product, not the material alone.

What does a bypass nipple do?

It routes water from the unloader back to the pump inlet or float tank while you are off the trigger. They are machine-specific parts, so replace them by part number.

Do nipple fittings need thread sealant?

NPT and BSP tapered threads do, either tape or paste. JIC nipples seal on the flare cone and need nothing on the threads.

How do you remove a stuck close nipple?

Use an internal pipe nipple extractor that grips the bore from inside. Pliers on the threads will destroy them. If it is rusted solid, cut it out and replace it in brass.