The principles of using airless
- 5 June 2017
- Posted by: Stm Coatech
- Category: Educational Articles
Currently, there are 100’s of paint manufacturers in the United States manufacturing over 600 million gallons of architectural and protective coatings annually.
Architectural coatings are primarily decorative coatings used to coat anything from homes to commercial and industrial buildings.
Protective coatings are primarily corrosion control coatings used to coat anything from bridges to water towers, preserving concrete and steel. Often these coatings are two-component materials.
The majority of coatings are sold at paint stores, generally to professional painting contractors.
Virtually every coating contains four basic components:
- Binder, Resin, or Polymer—holds together the other components prior to application and forms a protective film on the surface (the surface is also called a substrate) to which the coating is applied. Binders can be oils, varnishes and proteins.
- Pigment—fine solid particles that hide the surface providing decorative colors and sometimes corrosion resistance. Raw umber, a type of iron ore, is used extensively as a pigment and is olive green in color.
- Solvent—helps the flow of the coating material and aids in application. For example, water is a solvent for sugar. However, in many coating formulations, a chemical referred to as a solvent, may not be dissolving anything, but simply diluting or thinning the formulation.
- Additives—in general, manufacturers put additives into coatings for one or more reasons, including aiding in manufacturing, enhancing application characteristics, or improving the properties of the coating once it is cured. For example, some additives help prevent mildew from forming once the coating has cured.
Paints and other coatings are rated by the volume of solids they contain. While virtually everyone in the architectural coatings industry refers to the “low,” “medium,” and “high” solid content of coatings, there are no set amounts or limits placed on these categories. A typical set of values for coatings is:
- Low Solids = 20-30% solids
- Medium Solids = 30-50% solids
- High Solids = Up to 100% solids
Keeping in mind the typical amount of solids found in coatings (low, medium, or high), allows an easy method for displaying the solids content of popular architectural coatings.
Airless spray atomizes, or breaks up fluid into small droplets without the use of compressed air. In an airless system, fluid is pumped under high pressure through a spray tip. The tip size and pressure is what determines the material flow rate.
The tip also creates the fan pattern. In contrast, air spray systems inject compressed air into the fluid stream of paint to achieve atomization.
In airless spray, the fast moving high-pressure liquid stream provides the energy necessary to overcome the fluid’s viscosity (resistance to flow) and surface tension (a force that bonds the surface of a liquid together) to form a fine spray.
In the depiction of spray from a gun, high pressure forces fluid through a small nozzle (spray tip). The fluid emerges as a solid stream (sheet) at a high speed. When the solid stream hits the air, it becomes disrupted. This disruption breaks the fluid into fragments initially, then ultimately very small droplets that form the spray pattern.
Advantages of Airless Sprayers
Airless sprayers provide an easy and economical way to apply coatings.
Professional contractors prefer to use airless sprayers for several reasons, the most popular being:
- Speed—airless spraying is faster, thus, more jobs can be completed in less time, using less labor. Airless spraying is up to 10 times faster than brushing or rolling.
- Quality—airless sprayers produce an even coat of paint on all types of surfaces, leaving a consistent and high quality finish.
Versatility—airless sprayers can be used for a wide range of coating
materials, including interior and exterior jobs, and can easily be transported from job site to job site.
Research conducted by the Painting and Decorating Contractors of America (PDCA), an association of painting contractors and related industry
professionals, indicates that airless spraying can save painters between 50% and 75% of their painting time. Airless spray is:
- At least 10 times faster than brush applications
- At least 4 times faster than roller applications
Using a brush or roller application might seem cost-effective in the short-term, but in the long-run labor can cost at least twice as much!
Airless Spray for Uniform Coverage
It is important to consider how much faster spraying is compared to other methods. Equally important to your customer is how spraying gives a consistent quality finish, even over rough surfaces.
Airless spraying allows you to:
- Finish jobs quicker
— Finish within short weather windows
— Stay on a job site from start to finish, saving set-up labor
- Complete more jobs with less labor (fewer people headaches)
- Provide a consistent mil build so coatings perform better
- Apply a smooth quality finish
A- Spray Tip
- Controls the amount of fluid sprayed by using different orifice sizes
- Orifice shape determines the spray pattern.
- Many Graco tips can be turned to the reverse position by hand to blow out clogs
B- Motor & Drive System
•A heavy duty system that drives the pump
•Used to regulate the fluid pressure delivered from the pump
•Also called the Fluid Section
•Delivers a steady stream of high pressure fluid through the house to the spray gun
•Acts as the on/off valve for the material
Material is delivered to the gun at lower pressure than traditional airless
(500 – 1500 psi vs. 1500 – 3000 psi) and is partially atomized through a small tip. Full atomization is achieved by adding a small amount of air (5 – 35 psi) to the edges of the spray fan – resulting in a softer pattern, more control, higher transfer efficiency, and less overspray.
1-Spray Tip Air/Cap
•Controls the amount of fluid sprayed by using different orifice sizes and directs air into the spray fan
- Acts as the on/off valve for the material
3-Air Adjustment Valve
- Utilizes 8 air passages to deliver air closer to tip- resulting in a softer, more consistent pattern from start to finish easily under pressure
4-Bonded Fluid/Air Hose
- Fluid hose bonded with air hose eliminates managing two separate hoses
- Used to regulate the fluid pressure delivered from the pump
- Tight pressure control and fast response when spraying
6-Proven Endurance Pump
- Piston pump allows for consistent priming and pumping of even the heaviest materials
- Proven design and rugged construction
- Integrated compressor supplies air to the gun
Airless Spray Tips
This, small, exchangeable part plays a big role.
An airless spray tip:
- Determines the fluid flow = the amount of coating applied
- Determines the spray pattern (fan width)
Selecting the correct spray tip for the job is an important decision.
All Graco tips are made out of the highest grade of tungsten carbide, the most abrasive-resistant material used in the manufacturing of airless spray tips. Because each tip has its own particular use in the market place, Graco offers the following spray tip selection:
Reverse-A-Clean (RAC): Most widely used reversible tip on the market and can be used for a variety of coatings from lacquers to mastics. Reversible tips are an ideal way to eliminate downtime. With a reversible tip, clogs are cleared easily by simply spraying through the tip when in the reverse position. Contractors can change tip sizes in seconds, without removing the tip guard and housing. Reversible Tips are available in over 90 sizes and are rated at pressures up to 5000 PSI (blue or black handle).
Fine Finish Low Pressure SwitchTip :This tip incorporates a two-stage atomization process and creates a soft, feathered spray pattern at half the pressure, reducing overspray and extending tip and sprayer life. It allows the user to do fine finish work with an airless pump, which is faster than air spray or HVLP. Plus, it’s
fully swappable and comes in a full range of sizes that work on all Graco airless sprayers, using the same tips on handhelds and large airless sprayers.
WideRAC SwitchTip: This tip covers double the surface area in half the time with extra wide 24 inch (61 cm) pattern. WideRAC tips are made for higher production, new construction applications which require larger airless sprayers.
Heavy Duty Switch Tip : This tip is used for heavy coatings which require higher pressures to atomize. Heavy duty tips are still reversible, but add an extra thick twist lever to allow rotation in very sticky coatings such as coal tars and mastics (gray handle).
LineLazer & FieldLazer SwitchTip: Used with the LineLazer & FieldLazer Spray Units. Regular tips are designed for an overlapping spray technique. The LineLazer & FieldLazer tips are designed to provide a consistent pattern without soft edges to create clean, laser sharp lines (yellow handle).
Contractor Flat Tip: Standard airless tip available in a variety of sizes that are less expensive to purchase than RAC tips. If plugging occurs, the tip must be removed from the gun and cleaned or replaced.
Fine Finish Flat Tip: Sprays as fine a finish as the fine finish RAC but must be removed for cleaning when plugged. Typically, coatings used for fine
finish applications plug easily (i.e., lacquers). Therefore, if this tip is used, it is recommended that a Tip Filter Kit be used as well.
Rating Spray Tips
Spray tips are rated in terms of orifice size. The amount of paint that flows through the sprayer onto the surface depends on the tip size and pressure setting.
Size the spray tip according to the job and the tip rating of the sprayer. Make sure that the sprayer can support the tip you are planning to use.
Consider the paint/coating that will be sprayed – lacquers, stains, and enamels are light coatings that are sprayed with small tips, while exterior latex paints are much heavier coatings that require larger spray tips.
Multiple spray guns can be used with one sprayer. Make sure the multiple gun tip rating of the sprayer can support the tip sizes you plan to use.
Tip wear can cost you hundreds of dollars in wasted paint and labor. Choosing the right spray tip is essential for ensuring a quality finish no matter which coating material is being sprayed. All spray tips will wear with normal use. It is important to understand the wear effect coatings have on spray tips. All coatings contain solids that are abrasive; some are more abrasive than others. For example, latex paint may be very abrasive because of the solids used in the manufacturing process. The level of abrasiveness often depends upon how finely the solids have been ground. Graco tips are made out of the highest grade of tungsten carbide, the most abrasive resistant material used in manufacturing airless spray tips.
Effects of Tip Wear
When a tip wears, the size of the tip orifice increases and the fan width decreases. Tip wear affects the spray pattern. If the fan size has lost 25% of its original size, then it is time to replace the spray tip. Continuing to spray would simply result in a poor quality spray job, and a substantial waste of paint and labor.
12 in. Worn to Worn to Worn to
9 in. 7 in. 3.5 in.
Example: When a tip that had a 12-inch fan pattern is reduced to a 9-inch fan when worn, it will output 40% more paint on 25% less area. Overlapping to achieve a consistent mil thickness becomes impossible. The chart above illustrates the effects of a worn tip on a spray pattern.
Using a worn tip wastes paint and labor
Assume that paint costs $15 per gallon, labor costs $25 an hour, and the contractor sprays 5 gallons of paint per hour. If the contractor is using a worn tip (a 12 inch fan width worn to 9 inch) he will spend an additional $36.25 in wasted paint and labor per hour. If the painter continues to use the worn tip it will cost him about $300 per day!
Turn down the pressure as low as it can go while still spraying a good spray pattern to reduce your tip and pump wear. Turning down the pressure also saves paint by reducing overspray.
How Airless Sprayers are Rated by Manufacturers?
Airless sprayers are typically rated using these methods:
- Maximum tip size (with one gun, with two guns, etc.)
- Gallons per minute (gpm)
- Pounds per square inch or the maximum pressure (psi)
- Horse power (hp)
- gpm—(gallons per minute) a flow rate measurement associated with the pump’s output capacity and the tip orifice (hole) size.
CAUTION: There is no industry standard for rating a sprayer’s output capacity.
- psi—(pounds per square inch) a pressure measurement.
The pressure rating (e.g., 3300 psi) is the maximum working pressure (stall pressure) of the sprayer. That is, the maximum amount of pressure the sprayer is able to build. However, the pressure at the tip does not equal the maximum working pressure. Hose length, tip size, the type of coating being sprayed, and even the filters impact the amount of pressure available at the tip while spraying.
hp—(horse power) a performance rating for the sprayer’s motor or engine. There are a variety of motor types, operating speeds and torque capabilities available. This makes horsepower a confusing rating method for distributors and end-users alike. Some contractors prefer to have the biggest motor available because they believe it means more power and longer sprayer life. This is not necessarily true, the motor and sprayer should be matched to the jobs requirements.
Maximum Tip Size—a rating that indicates the largest tip size (i.e., orifice) a sprayer is capable of supporting, while maintaining a good spray pattern. The maximum tip size will depend on the type of coating being sprayed and the amount of pressure needed to atomize the coating.
Selecting A Sprayer: Eight Questions To Ask
What types of materials will you spray? Now and in the future?
The types of materials you spray will determine the size of the tips you use. If you plan to spray a variety of materials you have to consider buying a sprayer with more versatility.
How many gallons per week will you spray?
Purchasing a part-time sprayer to do a full-time job has disappointed many contractors. In the long run, saving money on a sprayer that is inadequate for the job, or not durable enough, will cost a lot in lost labor.
What power sources are available? Will most jobs be indoors or outdoors? Your answers will help choose a unit family (gas, electric, battery or compressed air) based on power sources alone.
What types of surfaces will you be spraying?
Will you be spraying on drywall, exterior siding, or concrete? You have to consider the tip sizes needed as well as the quality of finish required in order to choose the best sprayer for the job.
How many spray guns will you use at one time, now and in the future? If you plan to use more than one gun at a time, then you have to purchase a unit that has the ability to handle multiple guns.
What types of jobs will you bid?
Each job has its own requirements. New construction, residential work, and commercial jobs all vary in terms of: coatings used, crew size needed, and power sources available.
What hose lengths will you use?
Hose length depends on the job site, material being sprayed, tip size, and hose diameter. Your sprayer must be able to support the length of hose. Most
Graco sprayers use DC motors, which are able to support longer extension cord lengths than either AC or universal motors.
How much do you want to spend on a sprayer?
Buying a sprayer is an investment. You do not want to over-buy or under-buy. Keep in mind the cliché, “You can pay now or pay later”. Downtime resulting from an undersized, overworked sprayer or poor quality equipment can quickly wipe out any savings from the initial low purchase cost of the sprayer.
A good spray pattern indicates that the paint or coating is completely atomized and distributed evenly on the surface. Several techniques help determine the quality of the spray pattern and the quality of the finish.
- Adjusting the pressure
- Aiming of the spray pattern
- Movement of the spray gun
The following techniques ensure a long-lasting quality finish.
Adjusting the pressure for spraying
It is best to spray at the lowest pressure that completely atomizes the coating. The pressure control should be set at a low-pressure setting and slowly increased until the paint is completely atomized. If the spray pattern has fingers or tails, then the pressure should be increased.
Note: If the maximum pressure of the sprayer is not enough to achieve a good spray pattern, a spray tip with a smaller orifice should be used. To test the quality of the spray pattern, test patterns should be sprayed on scraps of cardboard or other waste material.
Aiming the Spray Pattern
The spray gun should be held approximately 12 inches (30.5 cm) from the surface, and aimed straight (both horizontally and vertically) at the surface. Extremely large tips will require you to move further away to achieve a good spray pattern.
Painting Inside Corners
When spraying corners the gun should be aimed into the corner, spraying along the corner, rather than spraying back and forth across the corner.
Controlling the Thickness of the Coating (Mil Build, 1 Mil = .001 in)
The key to proper coverage is controlling the coat thickness. Here are some helpful hints to ensure proper coverage and a quality finish:
Do not adjust the pressure to make the coat thicker or thinner. The pressure should be adjusted to the lowest pressure with a good spray pattern.
If the coating is too thick or running down the surface, one or more of the following will help:
- Move the spray gun faster
- Choose a smaller tip orifice size; be sure the sprayer is rated to handle the size tip being used
- Choose a tip with a wider fan
- Make sure the spray gun is far enough away from the surface (about 12″)
If the finish is not covering the surface, one or more of the following will help:
- Move the spray gun slower
- Choose a larger tip
- Choose a tip with a narrower fan width
- Make sure the spray gun is close enough to the surface (about 12″)
Sprayer pumps can be operated from three different power sources: electric motor, gas engine, or compressed air. In all electric and gas sprayers, the motor or engine creates a rotating motion that is transferred to the drive source of the fluid pump. Most of Graco’s sprayers use crankshafts and connecting rods to convert the rotating motion into the reciprocating action of the fluid pump. Hydraulics can also be used to transfer power from the source to the pump in the case of hydraulic sprayers.
In compressed air motors, the flow of air through the motor causes the motor piston and rod to move up and down. This reciprocating motion is then transferred from the motor connecting rod to the fluid displacement rod in the pump.
There are four types of motors available on airless sprayers: Universal, AC, DC and Brushless DC. The following chart compares the advantages and disadvantages of each type of motor.
DC Motor Technology Changes
In recent years DC motor technology has continued to improve. They:
- deliver higher output – increases flow rates
- have a much lower amp draw – allow longer cords
- are smaller and lighter – easier to move
- run cooler – longer life
- many are brushless – no open sparking
- have more horsepower – motors don’t work as hard, longer life
- are TEFC (totally enclosed fan cooled) – protects components from dirt, dust and overspray
A direct drive gas engine develops the horsepower to drive the pump and the electrical energy to power the clutch. This is known as a “direct drive” system. Direct drive units are the most energy efficient gas powered sprayers.
A hydraulic unit uses a gas engine to drive a hydraulic pump. The hydraulic pump draws hydraulic oil from a reservoir and pumps it to the hydraulic motor. This causes the hydraulic motor to reciprocate and power the fluid pump. This is known as a “hydraulic” system.
HandHeld Airless Sprayers
Graco has developed a line of handheld sprayers that utilize airless technology, referred to as ProSpray Technology. The breakthrough ProSpray Technology delivers Graco’s professional piston-pump design in a handheld sprayer giving painting contractors and consumers the freedom to spray wherever they want with true airless performance.
These handheld sprayers are operated by electric power or battery power sources, and are designed for small jobs and touchup work (1-3 gallons). The advantages of handheld sprayers are the professional spray finish, ultimate portability on the job and quick setup/cleanup compared to using a larger airless sprayer for small jobs. Startup, spray and cleanup can be done in minutes.
The handheld sprayers are similar to a traditional airless sprayer where they have a gun and pump built into the sprayer. The only major difference is that a handheld sprayer does not have an airless hose, making it easier to startup, less wasted material and easy to clean for small jobs.
There are several categories of handheld sprayers that are designed to spray specific materials.
The Proof is in the Pump
There is much discussion about pumps in the sprayer market; after all, most consider the pump the most important component of a sprayer. There are two general types of pumps offered in the airless sprayer market: diaphragm and piston. The following section describes the advantages and disadvantages of each type of pump for airless applications. All Graco airless sprayers use piston pumps.
How a Piston Pump Works
The double action displacement pump is a reciprocating pump with two ball checks (inlet and outlet ball checks) that control the flow of fluid through the fluid section. The displacement rod connects the pump’s internal components to the drive system. The rod moves up and down with the action of the drive system and motor. Fluid is loaded on the upstroke and displaced on both the upstroke and downstroke. Displacing fluid on both the up and down strokes ensures an even flow of fluid to the hose and gun.
How a Diaphragm Pump Works
A diaphragm pump uses the sprayer’s motor to create pulsing hydraulic pressure (a hydraulic system using oil) to drive the pump. During the upstroke or intake stroke, the diaphragm is pulled up, creating a partial vacuum within the paint chamber. The vacuum pulls the inlet valve open and the outlet valve is pushed closed by the spring and paint pressure in the hose. Paint is then drawn into the paint chamber. On the down-stroke or pressure stroke, the inlet valve is closed and the outlet valve is forced open as paint is discharged to the sprayer hose. Diaphragm pumps have a relatively small displacement volume. The pump must run fast (about 1725 cycles per minute) to deliver a steady flow of coating material.
The Power Of One
The ability to quickly change a pump on the job site can be the difference between a productive day spraying and one spent waiting on costly repairs. Graco has the only quick, easy, on-the-job pump replacement solution on the market today. With the Express and Endurance Pumps, Graco has
revolutionized the industry for every small and midsize sprayer built from 2004 through current. Clearly, the BETTER WAY to finish the job!
Pump Wear Parts
Wear parts are components in the fluid section that are designed to wear with use. Wear parts will need replacement or service during the life of the pump. Throat and piston packings are made to wear with use. This saves wear on the expensive hard parts of the fluid section (displacement rod, cylinders and sleeves). Replacing the packings right away when needed will save you time and money. Replacing packings in a service center takes little time, and the costs associated with repairs are much less than if the hard parts need replacing. The following parts should be checked periodically for wear:
Cylinder or Sleeve
Throat and Piston Packings
Balls (inlet & outlet) and Seats
Endurance Pump is the most rugged and reliable pump on the market today. This field proven design with long lasting V-Max Blue packing, Chromex rod and MaxLife pump coating delivers superior reliability and life for today’s coatings.
Graco’s exclusive ProConnect system allows quick removal or installation of your pump lower, with no tools required. The pump can easily be switched out in minutes right on the job site.
ProConnect prevents down time and avoids expensive labor when repair is needed.
The purpose of the pressure control is to regulate the spraying pressure. There are two types of pressure controls: Mechanical and Electronic.
Mechanical—a pressure control uses a micro switch to turn the motor on and off to maintain the desired pressure setting. The fluid pump runs until it reaches the set pressure—at this point the micro switch is activated and the motor shuts off. When the pressure decreases to a certain point, the micro switch closes and starts the motor, and the pump begins to run. The difference between when the motor turns off and on is known as deadband .
Electronic—the fluid pressure is sensed electronically and the signal is sent to a circuit board and compared to the signal received by the pressure control knob. The deadband on an electronic pressure control is typically around 50
psi; thus, the pump begins to run when the pressure drops to 50 psi. However, recent advances in Graco electronic controls have virtually eliminated deadband. Electronic pressure controls regulate the pressure in a manner that is constant and accurate, perfect for painting contractors who spray coatings at low pressures or who need to maintain constant spraying pressures.
Graco’s exclusive SmartControl, advanced microprocessor control delivers:
- A consistent spray fan at all spraying pressures.
- Zero deadband (no pulsating, steady consistent pressure) at lower spraying pressure, ideal for fine finish spraying.
- Automatically adjusts motor (pump) speed to best match the demand eliminating constant stopping and starting. In lower flow conditions the pump speed operates in slow stroking mode.
The Graco exclusive FastFlush mode greatly reduces cleaning time by increasing the pump speed up to 50% during low pressure cleaning. This creates a high turbulent flow through the pump, hose and gun helping to break loose residual paint or coating in less time. The FastFlush mode is activated with the Prime valve.
The WatchDog system automatically shuts the sprayer off when the paint supply bucket is empty to prevent damage of running the pump dry. This system is available on select Graco sprayers.
Airless Spray Hose
Airless spray hoses are available in different lengths, diameters, and pressure ratings. Selecting the proper hose is critical for maintaining optimal spraying pressure at the gun.
The length and diameter of hose you use affects the pressure drop of fluid to the spray gun. A longer hose has a greater pressure drop. A smaller hose diameter has greater pressure drop.
For ease of use, Graco hoses are more flexible and durable.
Hose length, diameter and the resulting pressure drop should be considered when selecting the size of airless sprayer to purchase.
If using two different diameter hoses coupled together, attach the larger diameter hose to the pump and the smaller hose to the gun to minimize pressure drop.
Pressure rolling is ideal when spraying is not possible. Simply pull the gun trigger when you need more paint and keep on rolling. No more climbing up and down ladders and stopping to dip the roller in a messy tray. Reach to the top without a ladder with fixed or telescoping extensions.
Lightweight and portable, the JetRoller consists of a spray roller, a spray extension and a hand roller in one complete kit. It combines the speed and coverage advantages of airless spraying with the classic technique and familiarity of rolling. The JetRoller is the perfect solution for Contractor’s looking for a flexible lightweight tool that is specifically designed to speed up paint rolling projects while virtually eliminating overspray. It fits existing airless sprayers and is a versatile, time-saving tool for any professional painter.
Maintaining Airless Equipment
Check your operators manual for the complete maintenance requirements of your specific Graco equipment.
Check the following components and tighten, clean or replace, as needed:
- Inlet Screen
- Manifold Filter
- Gun Filter
- Tip Filter
- Hose Connections
- Inlet Suction Tube
- Gun Body
- Tip Guard and Tip
- Trigger Safety
- Trigger Guard
- Power Cord
- Use the appropriate size filters for the material being sprayed (see the Correct Filter Reduces Tip Clogs chart).
Potential Hazards (and their icons)
The potential hazards that may occur when using Graco products are:
Fire and Explosions—can only occur if there is an ignition source combined with flammable vapors and air in the workspace. Ignition sources that can potentially lead to a fire or explosion are:
- Electrical switches or motors
- Open flames
- Static electricity
To prevent fire and explosion:
- Install and use proper ventilation
- Remove or extinguish all ignition sources, such as pilot lights, cigarettes, arcing motors, and others
- Ground all people, objects and spraying equipment in the spray area to prevent electrostatic discharge
- Use appropriate flushing procedures: use water, mineral spirits or lacquer thinner—never use gasoline!
- Use only grounded outlets, extension cords, and fluid hoses designed for high-pressure spraying that are in good condition—do not modify or remove electrical cords.
Skin Injection—spray equipment users and doctors often underestimate the seriousness of a skin injection injury and the medical complications that
could result. The injury might look like “just a cut” but should be considered a serious injury! The factors in the work environment that contribute to the risk of accidental skin injection are:
- A high-pressure fluid stream directed toward skin or clothing
- Removal of protective devices from equipment (gun safety, trigger guard, and tip guard)
- Unintended release of fluid pressure
- Failure to use a spray gun trigger safety
To prevent skin injection:
- Stay clear of high-pressure fluid streams and sprays
- Never remove protective devices, such as spray gun tip guards
- Use proper pressure-relief procedures
- Use proper flushing practices described in instruction manual
- Never try to stop leaks with your hands or body
- Always use the spray gun trigger safety when not spraying
- Don’t feel for leaks with your hands or a rag
Over-pressurization and Unintended Pressure Release—pressure-related injuries occur when equipment is over-pressurized and a component of the airless sprayer ruptures. Component ruptures are most often caused by:
- Exceeding the safe working pressure of a component
- Continued use of worn or damaged equipment
- Operator does not follow pressure-relief procedures
- Using replacement parts that are not genuine Graco parts
- Connections are not tight
- Connections are incompatible
- Connections or components are inappropriate for the pressure rating
- When equipment components rupture or an unexpected pressure release occurs, injuries are most often caused by spray in the face or eyes, a whipping hose, or projectiles.
To prevent pressure-related injuries
- Do not exceed the Working Pressure Ratings (WPR) of components, paying special attention to high-pressure equipment
- Use pressure-relief devices like pressure relief valves on sprayers
- Limit the air or hydraulic pressure to the motor so that the fluid pressure produced by the pump is less than the working pressure of all system components
- Do not repair permanently coupled hoses
- Use only genuine Graco service parts
- Do not modify Graco (or any other) parts
- Properly align spray tips to prevent back-spray
- Do not use low-pressure fittings on high-pressure equipment
- Use proper pressure-relief procedures
- Do not use damaged or worn equipment
- Check for proper connections and make sure they are tight before pressurizing the system
Injury from Moving Parts—injury from moving parts most often occurs after:
- Unintended contact with moving components (for example, air motor and pump displacement rods)
- Removal of equipment guards
- Failure to completely relieve fluid and air pressure when servicing equipment
To prevent injury from moving parts:
- Follow procedures for relieving fluid pressure whenever you stop equipment for service or repair
- Never operate equipment with guards or other protective devices removed
- Check regularly to ensure that safety devices are operating properly
- Properly use bleed type shutoff valves
Toxicity—is a potential risk when:
- Fumes from coating materials, fluids, or gas engine exhaust fumes are present in the work environment
- Toxic fluid makes contact with skin, nose, mouth, or eyes
To prevent toxicity:
- Use recommended Personal Protection Equipment (PPE) to avoid contact with hazardous materials
- Read and follow directions on all coating material labels and material safety data sheets (MSDS)
- Follow the recommendations of fluid manufacturers
• Never operate gas engines indoors
Electric Shock—the factors in the work environment that may potentially lead to electric shock are:
- Contact with electrically live or charged parts
- Improper grounding of equipment and other objects in the spray area
To prevent electric shock:
- Properly ground all objects in the system, including operators
- Follow the procedures in instruction manuals to avoid shocks from electrostatically charged components
- Never operate electric equipment when it is wet or when the surrounding area is wet
- Use only grounded outlets, extension cords, and fluid hoses designed for high-pressure spraying that are in good condition