The Sprayer and Duster Weekly Maintenance SOP

Purpose

Application equipment wears a little every day and fails on a particular day nobody notices: a trigger seal starts to weep, a tip opens up, a duster's charge cakes in a humid week, a power hose grows a bulge. Each of those either puts product somewhere it should not be or changes the rate going on the wall while the ticket still names the right product. This procedure walks every unit on a truck once a week, catches those failures before the route does, takes a leaking unit off the truck with a tag nobody can miss, and leaves a log of what was checked, replaced and measured. It keeps the calibration record true between calibrations.

Scope

Covers every hand-pump and motorized backpack sprayer, compressed-air hand can, bulb or hand duster, and truck-mounted power sprayer assigned to a truck, checked weekly on the last route day or the first morning of the week.

Does not cover: the full timed-output calibration and its interval, owned by 'Backpack and Power Sprayer Calibration'; taking a sprayer apart to replace seals, owned by 'How to Service a Backpack Sprayer Pump, Seals and Nozzle'; the rinse sequence and where the rinsate goes, owned by 'Equipment Decontamination and Rinsate Handling'; refilling and clearing a duster, owned by 'How to Clean, Fill and Maintain a Bulb Duster'; and the vehicle itself, owned by the service vehicle inspection SOP.

Roles and responsibilities

Procedure

1. Reconcile the units on the truck against the roster. Every unit carries a number on its tank or body. List each one and its type. Acceptance: the count on the truck matches the roster for that truck, and every unit has a legible number and product or dedication marking. Stop rule: a missing unit is reported to the route lead before the check goes on; an unnumbered unit is numbered and added to the roster, or it comes off the truck. Hazard: units may still hold mix, so you open nothing at this step; you read numbers.

2. Confirm each sprayer is empty and decontaminated before it is pressurized with water. The weekly check runs on clean water only. Acceptance: each sprayer has been through the rinse sequence in the decontamination SOP, with the third rinse running clear from the tip and the rinsate recorded to a lawful destination. Stop rule: a unit holding mix is rinsed first or skipped and noted; a unit with residue that will not rinse out is tagged and routed to decontamination. Hazard: rinsate is still pesticide on a contact and hand-to-mouth route, so chemical-resistant gloves and eye protection stay on, and come off before you write on the log.

3. Leak-hold each sprayer at working pressure for one minute. Fill with a few gallons of clean water, pump or charge to working pressure, and hold with the trigger closed for a full minute, the same hold the calibration card uses. Watch the lid, the pump, the outlet, the hose ends, the trigger valve and the nozzle cap. Acceptance: no drip or weep at any joint over the minute and pressure holding (a gauge, where fitted, holds its reading). Wrong looks like a bead at the trigger that the tech wipes off and calls dry. Stop rule: any drip or weep, bleed the pressure first. A lid seal or cap O-ring swapped from stock without opening the pump is allowed once, followed by a fresh full-minute hold from zero; any other leak, or a repeat after the swap, and the unit is tagged out of service at step 8 and goes to service. Nobody tightens a fitting under pressure to pass it. Hazard: stand to the side of the wand rather than in line with the tip, glasses on, tip below chest height, because a fitting that is going to let go does it under pressure.

4. Check the strainers and the tip against the record. Bleed the pressure, open the nozzle cap and look at the tip strainer and the basket strainer under the lid. Read the tip marking. Acceptance: strainers clear and intact, and the tip marking matches the marking on the unit's last calibration record. Wrong looks like a tip swapped on a route because the old one clogged, with nobody writing it down. Stop rule: a torn strainer is replaced and noted; a tip that does not match the record means the unit goes to calibration before it treats again, and the log says so. Hazard: the strainers hold residue the rinse missed, so gloves stay on; never blow through a tip by mouth.

5. Run the weekly output check on each sprayer. With the recorded tip and pressure, catch the output into a graduated container for the same time used at the last calibration, and compare it with the catch volume recorded there. Acceptance: within 5 percent of the calibration catch, the shop's band, written as a signed percentage with the subtraction shown. Wrong looks like a catch taken at a fresh full-pressure tank compared to a calibration taken at working pressure. Stop rule: outside 5 percent, the unit does not treat until it has been through the full calibration; a calibration date past the interval sends it there regardless of the catch. Hazard: hold the container by its side, never under the stream, and on a power rig never put a hand or glove in front of the gun, since a pinhole stream at that pressure injects under the skin.

6. Check each duster. Look at the cap seat and gasket, the tip and extension, the fill level and the dust itself, and the label. Then give two test puffs, downwind, away from your face, wearing the PPE the product label requires. Acceptance: cap seals, tip unsplit and clear, filled to about a third, dust loose and dry, labeled with product name and EPA registration number, and a fine haze from the test puff. Wrong looks like chunks or a lump from the tip, which is caked or overfilled dust. Stop rule: clumps, a wet charge or a missing label, the duster is emptied, dried and refilled per the duster HowTo before it treats. Hazard: dust is an inhalation route first, so test outdoors, never into the cab; a respirator, where the label requires one, is worn under a written program per 29 CFR 1910.134.

7. Check the power rig. With the engine or motor off and pressure relieved at the gun, walk the hose off the reel and look at its whole length; check the gun, the regulator, the tank lid and strainer, and the engine or pump items the rig's manual lists for weekly service. Then run it on clean water at working pressure and watch the gauge. Acceptance: no cut or abrasion through the cover to the reinforcement, no bulge, gun shuts off clean, gauge holds steady at the set pressure. Wrong looks like a bulge near the reel end, where the hose flexes most. Stop rule: any bulge, braid showing or leaking fitting, the rig is tagged out of service; it does not go out with a hose taped over. Hazard: a gasoline engine runs outdoors only, because exhaust carbon monoxide builds in a closed garage or shop bay; hands stay off a hot muffler; never feel for a leak with your hand at rig pressure.

8. Tag and park any unit that failed. Fill an out-of-service tag with the date, the unit number, the defect in plain words and your initials, tie it to the unit, and move the unit to the out-of-service bin off the truck. Call or message the route lead the same day. Acceptance: every failing unit is tagged, parked and on the log as out of service, and a spare is on the truck if the route needs one. Wrong looks like a tagged unit left on the truck "to fix tomorrow", which is how it goes out on a route. Stop rule: no spare available and the route needs the unit, the route lead reschedules the work that needs it; the tagged unit still does not go out. Hazard: bleed the pressure before the unit goes into the bin, so nobody picks up a charged tank.

9. Route lead review and release. The route lead reads the log, signs it, and routes each tagged unit to service or replacement. A tag comes off only after the unit has passed steps 3 to 5 again and the retest is on the log with initials. Acceptance: a signed log every week for every truck, and no tag removed without a passing retest line under it. Stop rule: a unit failing the same step three weeks running goes to the service manager for replacement rather than another repair. Hazard: none at this step; it is a review at a desk.

The record this produces

One weekly log per truck, filed with the equipment records, read by the route lead, the service manager and whoever answers a state inspector asking what equipment applied a product. Calibration says a unit could deliver the label rate on one day; this log says it still could on the day of the application.

 WEEKLY EQUIPMENT LOG   Truck 4   Week of 10/13
 Tech: R. Diaz          Route lead: M. Okafor
 ---------------------------------------------------
 UNIT  TYPE      CHECKS     PARTS      OUTPUT   INIT
 ---------------------------------------------------
 BP-7  backpack  L S T      none       +2.2 pc  RD
 BP-9  backpack  L FAIL     --         --       RD
       OUT OF SERVICE: drip at trigger, tag 0412
 HC-2  hand can  L S T      lid seal   -3.3 pc  RD
 D-3   duster    C F K P    none       haze     RD
 D-5   duster    C F K P    pebbles    haze     RD
 PR-1  power rig H G        none       +0.8 pc  RD
 BP-11 backpack  L S T      none       0.0 pc   RD
       spare, added for BP-9
 ---------------------------------------------------
 L leak hold 1 min   S strainers   T tip matches
 C cap and gasket    F fill, dry   K label
 P test puff         H hose        G gauge holds
 pc = percent against last calibration catch
 Route lead: BP-9 to service. Signed MO 10/14

Worked pass: truck 4, one unit tagged

Steps 1 and 2. Six units on the truck, six on the roster, all numbered. BP-7, BP-9, HC-2 and PR-1's tank were rinsed at the end of Friday's route, third rinse clear, rinsate into the marked container for the same product.

Step 3. BP-7 holds a full minute, dry. HC-2 weeps at the lid on the first hold; the flattened lid seal is replaced from stock and HC-2 is held again from zero, a full minute, dry. BP-9 forms a drip at the trigger valve at about 30 seconds. Step 3's acceptance fails on BP-9 and its stop rule triggers: BP-9 goes to step 8 and gets no further checks this week.

Steps 4 and 5. BP-7 and HC-2 strainers clear; both tips match their records. BP-7: calibration catch 45 fl oz, weekly 46. 46 minus 45 is 1 fl oz, and 1 divided by 45 is 2.2 percent over, inside 5. HC-2: calibration 30 fl oz, weekly 29. 29 minus 30 is minus 1, and 1 divided by 30 is 3.3 percent under, inside 5. All calibration dates are inside the interval.

Step 6. D-3: haze, about a third full, labeled. D-5: haze, but no agitator pebbles; three clean dry pebbles added and logged. Both pass.

Step 7. PR-1 hose walked off the reel: no cuts, no bulge. Run outdoors on clean water, gauge steady, gun shuts off clean. Catch 121 fl oz against 120 at calibration: 121 minus 120 is 1, and 1 divided by 120 is 0.8 percent over, inside 5.

Step 8. BP-9 bled, tagged 0412 "drip at trigger, 10/13, RD", moved to the bin, route lead messaged. Spare BP-11 is put through steps 3 to 5 before it goes on the truck: a full minute dry, tip matching, calibration catch 40 fl oz and weekly 40, 0.0 percent. It gets its own line on the log.

Step 9. The route lead signs Tuesday and sends BP-9 for service under the backpack service HowTo. Because its trigger valve is rebuilt, it is retested at steps 3 to 5 and sent through calibration before its tag comes off.

References

• See related: Backpack and Power Sprayer Calibration
• See related: How to Service a Backpack Sprayer Pump, Seals and Nozzle
• See related: How to Clean, Fill and Maintain a Bulb Duster
• See related: Equipment Decontamination and Rinsate Handling
• 29 CFR 1910.134 (respiratory protection), where a product label requires a respirator