Paint Sprayer & Pressure Washer Glossary

Use this glossary to understand key terms used in paint sprayers, pressure washers, and accessories.

Agitator Speed

The rate at which a paint sprayer’s agitator stirs the material in the hopper or tank to maintain consistency and prevent settling.

Air Cap

Component that shapes and directs airflow around the fluid stream to create the spray pattern.

Air Feed Tube

A small hose that supplies air pressure to pressurize siphon or gravity feed cups in HVLP systems.

Air Relief Valve

An adapter allowing non-bleeder guns to operate with turbine systems by venting excess air.

Airless

A spray method using high fluid pressure rather than compressed air to atomize coatings.

Airless Sprayer

Machine that uses a high-pressure pump to spray coatings without air assistance. Shop Airless Sprayers

Atomize

The process of breaking liquid into fine droplets to create a consistent spray.

Atomizing Set

A group of components—needle, nozzle, and air cap—that control spray pattern and flow.

Backflow

Reverse flow of paint or fluid, prevented by check valves.

Blow-By

Overspray that extends past the edges of the target surface.

Bleeder Gun

Spray gun that continuously emits air through the air cap.

Bleeder Valve

Adapter that allows non-bleeder guns to operate on older turbine systems.

Bounce-back / Back-spray

Droplets rebounding from a surface due to incorrect angle or pressure.

Centipoise

Unit of dynamic viscosity; 1 centipoise equals 0.01 poise.

Check Valve

One-way valve that prevents fluid or air from flowing backward.

Chassis

The frame that holds all components of a paint sprayer system.

CleanShot

Pressure-actuated valve preventing tip spitting on extension poles.

Convertible (Sprayer Type)

Sprayer that can switch between cart and portable configurations.

Dead Band

Pressure drop between trigger pull and pump restart, causing lag.

Degreasing

Removing grease with cleaning agents using sprayers or washers.

Detergent Tank

Reservoir holding soap or detergent for pressure washers.

Diaphragm

Flexible membrane in diaphragm pumps to move fluid.

Drive Train

Mechanical linkage between motor and pump.

Electronic Pressure Control

Digital system for maintaining constant spray pressure.

Extension Pole

A rigid or telescoping rod that attaches to a spray gun or tip guard, allowing the operator to reach high or hard-to-access areas without using a ladder. Shop Extension Poles

Fan

Shape of the spray pattern from the tip.

Fan Size

Width of the spray fan measured at 12 inches from surface.

Filter Kit

Collection of filters removing debris before spraying.

Filter Stand

Holder for paint strainers and cone filters.

Fine-Finish

Refers to smooth, detailed finishes like lacquer and polyurethane.

Fine-Finish Tip

Tip for low-pressure atomization for high-detail work.

Gravity Feed

Paint delivery method where cup sits above gun and uses gravity.

Gun Filter

Internal gun screen catching debris before the tip.

Hi-Boy

Upright cart sprayer configuration for large jobs.

Hopper

Container placed on top of sprayer to gravity-feed paint.

HVLP Sprayer

High Volume Low Pressure sprayer reducing overspray. Shop HVLP Sprayers

Inlet Ball

Check valve ball regulating paint intake into pump.

Inlet Tube

Tube drawing paint from container to pump inlet.

Intake Tube

Alternate term for the tube drawing fluid into the sprayer.

Low-Boy

Low-profile cart sprayer for stability and portability.

Manifold Filter

Filter inside sprayer body removing large particles.

Mil Build

Thickness of coating in thousandths of an inch (mils).

Motor

Engine (electric or gas) powering the sprayer pump.

Needle

Rod inside gun regulating flow and sealing the tip.

Nozzle

Component that determines flow rate and spray pattern.

OneSeal

Single-piece seal between tip guard and spray tip.

Orifice

Opening in spray tip controlling flow and pattern size.

Outlet Valve

Valve controlling fluid leaving pump toward the gun.

Overspray

Atomized material that lands outside the intended target.

Packings

Seals around piston rod preventing fluid leaks.

Paint Cup

Container attached to gun holding material to be sprayed.

Paint Hopper

Large, open container for holding paint in industrial sprayers.

Paint Viscosity

The thickness of paint affecting flow and atomization.

Pole Gun

Spray gun mounted on extension pole for reach.

Portable Paint Sprayer

Compact sprayer designed for small to medium projects. Shop Graco Handheld TC Pro Cordless Airless Paint Sprayer

Pressure Control

Device regulating output pressure to hose and gun.

Pressure Pot

Pressurized container feeding paint to the gun.

Pressure Roller

Roller attached to hose for coating without tray dipping.

Pressure Switch

Switch that triggers pump on/off based on pressure.

Prime / Spray Valve

Valve toggling pump between priming and spraying modes.

Priming

Filling the system with material and removing air prior to spraying.

Pump

Core mechanism moving and pressurizing fluid within a sprayer.

Pump Armor

Protective compound preventing pump corrosion during storage.

Pump Cylinder

Chamber where piston moves to generate high pressure.

Quick-Connect Coupler

Fitting enabling fast, tool-free hose and accessory changes.

RAC (Reverse-A-Clean)

Feature allowing tip rotation to clear clogs without removal.

Return Tube

Tube returning excess paint to container during priming.

Rod

Piston rod converting motor motion into pump action.

Roof-Rig

Hydraulic sprayer configuration for applying roof coatings.

Seals & O-Rings

Components providing leak-free seals at connections and moving parts.

Shadows

Areas missed by spray due to surface texture or angle.

Siphon Feed

Paint delivery method drawing material up from cup below gun.

SmartControl

Microprocessor control ensuring consistent pressure and no dead band.

Spray Fan

Fan-shaped spray pattern produced by atomized paint.

Spray Gun

Handheld device controlling paint flow and atomization. Shop Spray Guns

Spray Pattern

The shape and distribution of atomized paint exiting the tip.

Spray Tip

Nozzle component controlling flow rate and pattern size. Shop Spray Tips

Stage (as in "Stage 4 Turbine")

Number of turbine stages indicating air volume in HVLP systems.

Stand (Skid)

Frame-mounted sprayer without wheels for stationary use.

Suction Tube

Tube drawing material from container into the pump.

Throat Seal Liquid (TSL)

Lubricant keeping packings wet and preventing overspray buildup.

Tip Extension

Extension tube increasing reach for high or recessed spraying.

Tip Guard

Protective piece preventing direct contact with the spray tip.

Tip Sizes

Measurements indicating the orifice size and fan width of tips.

Trigger Gun

Gun using a trigger to control paint flow on demand.

Trigger Lock

Safety feature locking the trigger to prevent accidental spray.

Turbo Nozzle

Rotating tip concentrating spray for deep cleaning applications.

Unloader Valve

Valve diverting water back to pump when trigger is released.

Viscosity

Resistance of fluid to flow, affecting atomization and spray.

Wand

Extension lance allowing reach to high or distant areas.

Whip Hose

Short, flexible hose section near the gun to reduce fatigue.

Zahn Cup

Device for measuring liquid viscosity using a standardized cup.

Chemical Injector

Device that injects detergent or cleaning solution into the water stream.

Cleaning Units

A metric combining PSI and GPM to indicate overall cleaning power.

Degreasing

The use of cleaning agents and pressurized water to remove grease.

Detergent Tank

Onboard reservoir holding cleaning solution for mixing with high-pressure water.

Electric Pressure Washer

An electrically powered washer offering quieter and more portable operation.

Gas Pressure Washer

A gasoline-powered washer delivering higher PSI for heavy-duty cleaning tasks.

GPM (Gallons Per Minute)

The flow rate of water from the pressure washer, impacting cleaning speed and coverage.

Hose Connector

A fitting for attaching hoses to the washer or spray gun securely.

Hose Reel

A spool that stores and organizes the high-pressure hose when not in use. Shop Hose Reels

Pressure Hose

A reinforced hose that carries water from the pump to the gun at high pressure.

Thermal Relief Valve

A valve that vents hot water to prevent pump overheating during idle times.

Trigger Gun

A handheld gun with a trigger for controlling water flow from the washer.

Turbo Nozzle

A rotating nozzle that concentrates water into a powerful circular spray for deep cleaning.

Unloader Valve

A valve that diverts water back to the pump when the trigger is released, preventing pressure buildup.

Wand

An extension lance that allows users to reach high or distant cleaning areas.

Shared Terms

Extension Wand

An attachment that extends the reach of a spray gun or pressure washer wand.

Lubrication Fluid

Oil or synthetic fluid used to reduce friction and wear in pumps and moving parts.

Maintenance Kit

A set of tools and replacement parts for routine servicing of equipment.

Pump

The component that creates pressure by moving fluid through the system.

Quick-Connect Coupler

A fitting that allows fast tool-free connection of hoses and accessories.

Seals & O-Rings

Rubber or synthetic rings used to prevent leaks at joints and connections.

Viscosity

The resistance of a fluid to deformation or flow, affecting performance.

Whip Hose

A short, flexible hose segment between gun and main hose for maneuverability.