If you are pulling plugged tips every few passes, the tips are not the problem. Something upstream is letting debris through, or the screens are the wrong mesh for the tips you run. Sprayer filtration is a chain: a coarse screen at the tank or suction to protect the pump, a finer line strainer on the pressure side to protect the boom, and a tip strainer at the nozzle to protect the orifice. Each one should be finer than the one before it. The trick is matching the last screen to the tip size without choking the flow.
1. Find where the plugging comes from
- Same tips plug every time, near the boom end — debris settling in the boom plumbing. Pull the boom end caps and flush. Check the tip strainers in those bodies; they may be missing.
- Everything plugs after a tank of a dry product — undissolved powder or granule. Agitate longer, use a 50 mesh line strainer instead of 80 or 100, and consider 50 mesh at the tip instead of 100 mesh.
- Plugging started after a repair — teflon tape, poly shavings or a cut gasket from the new fitting. Pull the line strainer bowl; you will usually find it.
- Black flakes or rubber crumbs — a hose, diaphragm or gasket breaking down. Find the chemical-attacked part and replace it; the screens are only catching the symptom.
- Rust — steel tank, steel boom pipe or a cast pump. A 50 mesh screen catches most of it; the fix is in the tank.
- Pump losing prime or cavitating after you went to a finer suction screen — suction screen too fine. Go back to 16 or 20 mesh on the suction side.
2. Why mesh matters
Mesh is wires per inch, so the number goes up as the hole gets smaller. On Banjo's stainless screens, 16 mesh is about a 1190 micron opening, 30 mesh 595, 50 mesh 297, 80 mesh 177 and 100 mesh 149 microns. The screens are color-coded by rib: brown-red 16, flame red 30, gentian blue 50, zinc yellow 80, traffic green 100. TeeJet's 8079-PP tip strainers follow the same colors: white 24, blue 50, yellow 80, green 100. Open area drops as mesh goes up, so a 100 mesh screen in a 1" T strainer passes a lot less than a 16 mesh one. That is why the suction side stays coarse: a fine screen there starves the pump.
At the tip, TeeJet's guidance is simple. Use 100 mesh strainers for low-flow tips, typically 02 size and smaller, and 50 mesh for larger tips. A 50 mesh tip strainer behind an 015 tip will let through particles that plug the orifice; a 100 mesh strainer behind an 06 tip plugs itself before the tip ever would.
3. The strainer and screen for your setup
Banjo's poly T strainers use glass-reinforced polypropylene bodies, 316 stainless screens and an EPDM bowl gasket as standard, with FKM (Viton) available for oil-based or solvent-type carriers. Pressure rating is 300 psi on the current LST series; check the bowl if you have an older 150 psi body.
4. Getting it right
- Depressurize and open the strainer over a bucket. The bowl holds concentrate.
- Finer downstream, never finer upstream. Suction 16–30, line 50, tip 50 or 100. If the line strainer is finer than the tip strainers, it plugs first and you lose pressure across the whole boom.
- Match tip strainers to the smallest tip you run on that boom, not the biggest.
- Pull and rinse the line strainer every tank of dry product and at the end of every day. A screen packed with powder passes less than a plugged tip.
- Tip strainers only work in bodies that have them. Count them when you change tips; a missing one is the first thing to check on a body that keeps plugging.
- If a screen tears, do not reuse it. A 50 mesh screen with a hole is a 0 mesh screen.
- Replace the bowl gasket when you replace the screen. A sucked-in gasket on the suction side is an air leak and a prime problem.
Not sure which strainer or screen you need? Send a photo of the strainer body and the tip you run to sales@spraycenter.com or call (509) 838-2209.
Spray Center Electronics stocks Banjo, Green Leaf, Hypro and TeeJet line strainers, screens, gaskets and tip strainers in Spokane, WA. Part numbers here come from the manufacturers' parts sheets; if your meter, boom or fittings have been changed over the years, send a photo of the tag or the part and we'll match it before you order.