Polypropylene Fittings for Chemical and Soft Wash Plumbing

Bleach eats brass. That is the whole reason this category exists. Polypropylene fittings from Banjo and AR do not corrode, do not react with sodium hypochlorite, and cost less than the metal they replace. If you are plumbing a soft wash skid or a chemical transfer setup, call 301-519-9274 and read us the size stamped on your old fitting. We will match it in minutes.

Why Poly Belongs on the Chemical Side of Your Rig

Copper-based metals do two bad things around sodium hypochlorite. They corrode, and the copper they shed actually speeds up the breakdown of the bleach in your tank. So you get a weaker mix and a seized fitting at the same time. Carbon steel rusts even faster, and even 316 stainless can stress-crack after long chloride exposure. Polypropylene stays chemically inert at the strengths soft washers actually run, 12.5 percent SH and below. That is why every serious soft wash rig plumbs the chemical side in poly and hose barb connections.

The trade-off is pressure. Poly fittings are built for the suction and low-pressure side of the system, generally in the 100 PSI class depending on size and style. Keep them on tank plumbing, 12V pump lines, batch mixing, and downstream chemical feed. High-pressure discharge plumbing still belongs to stainless steel or brass on the water side of the machine.

Know Your Poly Fitting Types

Most of this collection is Banjo cam lever hardware, the yellow-armed quick couplers you see on ag sprayers and soft wash trailers. A male adapter slides into a female coupler, the arms cam down over a groove, and the gasket seals without any threading. You can break down a tank or swap a hose in seconds with wet gloves on. Beyond couplers, the lineup covers:

• Hose barbs that grip chemical hose with a clamp, from 1/2" pump tubing up to 1-1/2" transfer line
• Bulkhead fittings that pass through a tank wall and seal with a gasket, the standard way to plumb an outlet on a poly tank
• Line strainers with 80 mesh screens that catch debris before it reaches your 12V pump valves
• Poly check valves that stop chemical from draining back down the line when the pump shuts off
• Thread adapters for jumping between MPT, FPT, and barb ends

Getting Size and Thread Right

Poly fittings use standard NPT pipe threads, so a 1" MPT poly adapter threads into the same port as a 1" brass one. The common soft wash sizes are 1/2" for pump plumbing, 1" for chemical transfer and downstream feed, and 1-1/2" for tank fills and batch mixing where you want volume moving fast. One warning from the counter: poly threads are softer than brass. Wrap them with thread tape, start them by hand, and stop at snug. A wrench-tight poly fitting cracks at the hex, usually a week later when you are 40 minutes from the shop.

Poly Fitting Picker

Prices change with vendor costs. Call for current availability before you drive over.

From the Field

The repair pattern we see on soft wash trailers is predictable. It is almost never the poly body that fails first, it is the gasket inside the cam coupler. SH dries out standard gaskets over a season, and a hardened gasket weeps chemical on your trailer deck. Keep a couple of spares in the glovebox and swap them at the first drip. Second pattern: guys skip the line strainer to save 80 bucks, then burn up a 12V pump on tank grit that a mesh screen would have caught. The strainer is cheaper than the pump every single time. Last one: rinse the chemical side with fresh water at the end of the day. Two minutes of flushing doubles the life of every gasket, valve, and pump diaphragm in the line.

Related Collections

• Soft wash equipment
• Chemical hose
• Hose barbs
• Chemical strainers
• Check valves
• 12 volt pumps
• Chemical injectors
• Water tanks
• Brass pipe fittings
• Local pickup at our Gaithersburg, MD store

Frequently Asked Questions

Will polypropylene fittings handle 12.5 percent sodium hypochlorite?

Yes. Poly is inert to SH at the concentrations used in soft washing, including straight 12.5 percent. Heat and sunlight break down the bleach itself long before they bother the fitting.

What pressure are poly fittings rated for?

They are low-pressure hardware, generally in the 100 PSI range depending on size. That covers tank plumbing, 12V pumps, and downstream feed lines. Never put poly on the high-pressure side of a pressure washer.

Why did my brass fittings turn green on the chemical line?

Bleach attacks the copper in brass. The green crust is corrosion, and the dissolved copper also degrades the SH in your tank faster. Swap the chemical side to poly and both problems go away.

Do I need thread tape on poly threads?

Yes, use PTFE tape on every threaded poly joint. Then hand-tighten plus a light snug at most. Overtightening is the number one cause of cracked poly fittings we see.

How does a cam lever coupler work?

The male adapter slips into the female coupler and two cam arms fold down, pulling the adapter tight against an internal gasket. No threads, no tools, and you can disconnect a wet chemical line in about two seconds.

What sizes should I plumb a soft wash skid with?

Most builds run 1/2" at the pump, 1" for chemical supply and downstream feed, and 1-1/2" for tank fill lines. If you are unsure, call 301-519-9274 and we will walk your plumbing diagram with you.