How to Refill and Maintain a Pressure Sprayer

Refilling a professional pressure sprayer is a six step job: check the seal material suits the chemical, release the pressure, unscrew the head and fill to the scale leaving an air buffer, refit the head hand tight, pump around 30 strokes, then spray and top the pressure up as it drops. Done that way the same unit goes back to work refill after refill instead of into the bin.

This guide covers refilling, pressurising, cleaning down and repairing a trade sprayer. The figures quoted are Klager's, published for their own pump sprayers, so check the manual where your model differs. Get the chemical question right first, every time, because the wrong seal makes the rest of it academic. That part is covered in full in the Chemical Compatibility Guide.

Before you open anything. Release the pressure first. A sprayer that has been standing in the sun can still be charged, and a head unscrewed under pressure puts chemical in your face. Wear the PPE the SDS calls for.

Why refillable and repairable wins on cost and waste

An aerosol is mostly packaging. The can, the propellant and the nozzle all go in the bin once the product is gone, every time. A disposable trigger bottle is the same problem in a smaller package: the trigger gives out, or the bottle does, and the whole thing is binned.

A refillable sprayer flips that. You buy the chemical in bulk and decant it, so the spend goes into the product rather than the packaging. When something wears, and on a chemical sprayer it is nearly always a seal, you fit a seal kit instead of buying another unit. Klager has worked to that principle since 1949, and its position on a failed sprayer is blunt: it "can simply be repaired". That only holds up if somebody stocks the parts, which is the job NORA PRO does at this end.

How to refill a pressure sprayer

1. Check the resistance version against the chemical, first. VITON (FKM) is the acid and petroleum solvent seal. EPDM handles bleach, caustics, alkalis and ketones such as acetone and MEK, but not petroleum solvents. Confirm concentration and temperature against the SDS before you decant anything. Detail in the Chemical Compatibility Guide.
2. Release the pressure. Vent the unit through the relief valve before you touch the head, even when you are sure it is empty.
3. Unscrew the head and fill to the scale, leaving the air buffer. The empty space above the liquid is what stores the pressure, so a bottle filled to the brim will not hold a charge. Do not fill with liquid hotter than 30 degrees C.
4. Refit the head. Start the thread square and tighten by hand. Cross-threading a head is the quickest way to write off a good bottle.
5. Pump about 30 strokes. That is the working charge from empty. The pressure relief valve limits the container to 3 or 4 bar depending on the model, so it vents rather than over-pressurising.
6. Spray, and top the pressure up as it drops. A few strokes during the job keeps the pattern even.

The numbers, in one place

What	Figure
Pump strokes from empty	around 30
Container pressure	limited to 3 or 4 bar by the pressure relief valve, depending on model
Maximum fill temperature	30 degrees C
Fill level	to the scale on the bottle, always leaving an air buffer
Pump piston O-ring lubricant	silicone oil, and on EPDM seals silicone oil only
Storage	depressurised, out of heat, cold and direct sunlight

These are Klager's published figures for their own pump sprayers. Confirm against the manual before you apply them to another brand.

Care and maintenance after the job

• Decant what is left back into the original chemical container. Do not leave mixed chemical sitting in the sprayer. It works on the seals for days while nobody is watching, and next week nobody remembers what is in an unlabelled bottle.
• Rinse the bottle with clean water, unless the SDS says water is the wrong thing for that chemical, and pump some through the lance so the line and the nozzle come clean too.
• Grease the pump piston O-ring every clean down. It does the work and it dries out first.
• Silicone oil only on EPDM seals. Petroleum-based greases swell EPDM and destroy it, which is the same reason EPDM is the wrong seal for petroleum solvents.
• Store it depressurised, out of heat, cold and direct sunlight. UV is what turns a sound bottle brittle.

Repair, do not replace

NORA PRO stocks the wear parts, so a sprayer that has stopped working is more often a parts job than a replacement. Parts and seal kits covers VITON and EPDM seal kits, pumps, triggers, lances and nozzles for the brands we carry. NORA PRO holds genuine Klager parts as the exclusive Australia and New Zealand distributor of Klager. Where the fault is a worn tip rather than a seal, look at spray guns and lances and accessories.

Match the seal kit to the chemical, not to the unit as it was bought. If a sprayer has moved off a degreaser and onto a descaler, the kit changes with it.

Klager's environmental credentials, and why they are not NORA PRO's

The environmental credentials behind this equipment belong to Klager and were earned at their factory in Germany. NORA PRO distributes that equipment in Australia and New Zealand and holds none of them, so they are set out here attributed to the company that holds them.

• Klager manufactures under the DIN 14001 environmental management standard, audited internally and externally.
• Klager's German factory has run on 100 percent renewable electricity since 1 January 2021, from Scandinavian hydro.
• Klager regrinds its own production waste into granulate and re-uses it in new bottles and components.
• Klager offers a fill container made from renewable raw materials, which Klager describes as fully biodegradable, from its factory on request. It is not a line NORA PRO stocks here.

NORA PRO holds no environmental certification of its own, buys no Scandinavian hydro, and makes no claim about the footprint of its own freight in Australia. What NORA PRO says in its own voice is narrower, and it is a fact about the goods. The sprayers we supply are refillable and repairable, and we hold the seal kits and spare parts here to repair them. Fixing a unit instead of replacing it is your saving and your waste avoided.

When you are not sure the sprayer suits your chemical

Klager runs a Chemical Application Center in Germany, staffed by applications engineers, spray technology specialists and PhD chemists. They run immersion and practical resistance tests on the customer's actual liquid, taking anywhere from 14 days to 24 months, then recommend the resistance version to use. NORA PRO has no laboratory, no chemists and does no testing of its own. What we have is the distributor relationship, so send us the SDS and the job and we will put the resistance question to Klager.

Tell us the chemical and the job and we will spec the unit. Request a quote. Resellers, chemical companies and trade suppliers, apply for a trade account for wholesale supply of sprayers and parts. Buying rather than repairing this time? Start with the Sprayer Selection Guide.

Frequently asked questions