Chemical Strainers for Soft Wash and Downstream Injection

When an injector quits pulling soap mid job, the cause is usually a five dollar screen nobody checked. A chemical strainer sits at the end of your pickup tube and stops grit, surfactant clumps, and tank crud before they reach the injector orifice. Sun Brite Supply keeps weighted strainers, check valve versions, and inline filters on the shelf in Gaithersburg. Call 301-519-9274 if you are not sure which end of the line needs which filter.

Picking the Right Chemical Strainer

Weighted or Not

A weighted strainer pulls the end of your suction hose to the bottom of the bucket or tank and keeps it there. That sounds minor until you watch an unweighted line float to the surface halfway through a roof and start sucking air. For any open bucket or drum setup, the weighted style is the default. The weight also keeps the screen pointed down into the liquid, so you draw chemical to the last inch of the container instead of leaving a quart behind.

The Check Valve Question

Strainers come with or without a built in check valve, and contractors argue about it. The case for the check valve: it holds prime in the line, so the injector picks up chemical the moment you switch tips instead of waiting for the hose to refill. That matters most on 12 volt systems and long suction runs. The case against: it is one more moving part, and a sticky check ball adds restriction that weakens draw. Most downstream injectors already have their own check valve, so some flatwork guys run the plain version and never miss it. We stock both for under six dollars, so try each and see which your rig likes.

Plastic or Brass Around Bleach

For SH and soft wash mixes, plastic bodied strainers with stainless screens last longest, because bleach slowly eats brass. Chrome plated brass versions are heavier, which improves pickup in deep drums, and they hold up fine for detergents and degreasers. If you run 12.5 percent SH daily, buy plastic and treat the strainer as a wear item. At three or four dollars each, keep two spares in the glove box.

Do Not Forget the High Pressure Side

A pickup strainer protects the injector. It does nothing for the debris already in your hoses. An inline 5,000 PSI filter at the gun or lance catches rust flakes and Teflon tape shreds before they plug a nozzle, which is the difference between swapping a tip and clearing a blockage forty feet up a ladder. Run both and nozzle clogs mostly disappear.

Chemical Strainer and Filter Lineup

The weighted plastic and ZF2 strainers are counter stock items here. Call 301-519-9274 to confirm the rest before you make the drive.

From the Field

Weak chemical draw gets blamed on the injector nine times out of ten, and the injector is innocent about half the time. Before you rebuild anything, pull the strainer and look at the screen. Surfactant residue dries into a film that chokes flow, and one afternoon of drawing from a drum with sediment in it will mat the mesh. Rinse the screen in warm water at the end of any chemical day. While you are at it, check that the pickup hose has not gone stiff and cracked at the barb, because a pinhole above the liquid line kills suction just as dead as a clogged screen. The parts that fix all of this cost less than lunch. That is why we tell people to buy strainers in pairs and hose by the foot.

Related Collections

• Chemical injectors and chemical hoses
• Soft wash equipment and X-Jets
• Chemical handling and chemical additives
• Strainers and inline filters
• Water filters and all filters
• Soap and foam tips
• 12 volt pumps
• Visit the Gaithersburg pressure washer store for counter help

Frequently Asked Questions

Do I need a check valve on my chemical strainer?

It depends on your setup. A check valve holds prime so chemical arrives faster when you switch to the soap tip, which helps on 12 volt systems and long suction lines. Most downstream injectors already have a check valve of their own, so a plain strainer draws slightly stronger. Both styles cost only a few dollars, so testing each is cheap.

Why did my injector stop pulling chemical?

Check the cheap parts first. A clogged strainer screen, a cracked pickup hose, or a stuck check ball causes most draw problems. Rinse the screen, inspect the hose barb, and only then look at the injector itself.

Should I use a plastic or brass strainer with bleach?

Plastic with a stainless steel screen. Sodium hypochlorite corrodes brass over time, so brass strainers belong on detergent and degreaser lines. If you soft wash daily, treat plastic strainers as consumables and keep spares.

What hose size do these strainers fit?

Most weighted chemical strainers fit the standard 1/4 inch and 3/8 inch ID suction hoses used on downstream injectors and soft wash systems. Check the barb size on the product page, and call 301-519-9274 if your hose is an odd size.

How often should the screen be cleaned?

Rinse it at the end of every chemical day, and inspect it any time draw feels weak. Dried surfactant and tank sediment build a film that chokes flow well before the screen looks visibly blocked.

What is the difference between a chemical strainer and an inline filter?

The strainer works on the suction side, keeping debris out of the injector. An inline high pressure filter installs near the gun or lance and protects the nozzle from rust and scale already in the system. A rig with both rarely sees a clogged tip.