HIGH VOLUME LOW PRESSURE PAINT SPRAY SYSTEM

Revision Date: 9/01
Process Code: Navy/Marines: ID-06-04, ID-05-01/-02; Air Force: PA01; Army: PNT
Usage: Navy: High; Marines: High;
Army: High; Air Force: High
Compliance Impact: Medium
Alternative for: High Velocity Paint Spray Systems
Applicable EPCRA Targeted Constituents: Toluene (CAS: 108-88-3), Xylene (CAS: 1330-20-7), Methyl Ethyl Ketone (CAS: 78-93-3), Acetone (CAS: 67-64-1), N-butyl Alcohol (CAS: 71-36-3), Lead (CAS: 7439-92-1), Chromium (CAS: 7440-47-3), Zinc Compounds

Overview: A High Volume/Low Pressure (HVLP) paint spray system is an efficient technology for the application of paint to specific workpieces. These systems operate at low pressures, which result in the application of paint at low velocities.

HVLP paint systems atomize paint by delivery a high volume of air at a low pressure (less than 10 psi). Because the atomized paint particles are delivered at low velocities to the object being painted, less paint is lost as overspray, bounce, and blow back. Typically the transfer efficiency with HVLP paint system is 50 to 65%.

The effect of this technology on pollution prevention concerns the fact that delivering at low velocities results in a higher transfer efficiency, compared to conventional paint spray systems. In conventional spray systems, a stream of liquid paint is met by jets of pressurized air which form the paint into a fine mist. A typical system employs 100 psi of constant air pressure in a volume of approximately 25 cfm. The atomized paint particles travel at high velocities and tend to bounce off the object being painted rather than adhering to the surface. In addition, the expanding high pressure air (above 100 psi) passing through the small face cap openings causes turbulent flow of the paint stream following air currents within the paint booth. The amount of paint that bypasses the workpiece (overspray) is relatively high for air pressure atomized spray painting. Transfer efficiencies of 25 to 30% are associated with conventional spray systems.

There are three other types of high transfer efficiency paint guns: airless (also called pressure atomized), pressure atomized air-assisted, and electrostatic. Electrostatic paint spray systems are discussed in a separate Pollution Prevention Opportunity Data Sheet, Electrostatic Paint Spray System. The other two systems are described below.

Airless spray painting systems atomize paint by forcing it through a small tip orifice at high fluid pressures (1,500 to 3,000 psi). Transfer efficiencies with airless spray painting are lower than HVLP systems, typically 20 to 40%. Large areas can be painted quickly by pressure atomized paint systems. This technology is, however, inappropriate for fine finishing work, because a large quantity of paint is delivered with particles that are less finely divided.

Pressure-atomized, air-assisted systems combine the features of the air atomized (conventional) and airless systems. An airless fluid spray nozzle is used to atomize the coating into a fan pattern at high pressures (400 to 800 psi). A second, low-pressure air stream (10 to 30 psi) is injected after the nozzle to improve atomization and the spray pattern. This system is reported to provide the fine control of air-atomized spray guns and the improved transfer efficiencies of airless systems. Transfer efficiencies for pressure-atomized, air-assisted systems are comparable to HVLP systems. The airless systems generate significant waste during clean-up and material changes, as compared to the HVLP system.


Compliance Benefit: The higher transfer efficiency achieved by the high volume, low pressure paint spray system reduces the total volume of paint that is used, which in turn results in the following compliance benefits:
  • reduced emissions of volatile organic compounds (VOCs) used as solvents in paints which are associated with formation of smog and are typically regulated by state and local air pollution control districts;
  • reduced emissions of hazardous air pollutants (HAPs) used as solvents in paints which are most typically associated with increased cancer risk and which are regulated under federal, state and local regulations including National Emission Standards Hazardous Air Pollutants (40 CFR 63);
  • reduced emissions of substances which may result in reduced reporting requirements under the toxic release inventory (TRI), Tier I/Tier II, and other SARA Title III reporting requirements (40 CFR 300, 355, 370, and 372; and EO 12856); and
  • potentially reduced occupational exposures which are regulated under 29 CFR 1910.120.

Specific compliance benefits include: 1) reduced recordkeeping and reporting requirements under the Title V, the NESHAP Program, and under SARA programs and 2) reduced permit fees.


Materials Compatibility:
HVLP paint spray systems can be used in a wide variety of painting applications. The finer atomization of HVLP systems produce smoother surface finishes. There are many paint gun models, with a variety of tip sizes to accommodate most coatings, including solvent-based paints, water based coatings, fine finish metallic coatings, high-solids polyurethane, contact adhesives, varnish, top coats, lacquer, enamel primer, latex primer, epoxy, and vinyl fluids. The manufacturers guidance should be followed in all maintenance and operating aspects, particularly when spraying high solids paints. Clogging problems can hamper painting operations if the technician is not familiar with the equipment or the application techniques required. The efficiency of this system is reduced if painting is in exposed areas.


Safety and Health: Proper design, operation, and maintenance of the equipment is required for its safe use. The spray booth must be well ventilated. The coating characteristics and application procedures (such as surface preparation, spraying and clean up) present additional health concerns. The inhalation of lead or zinc can irritate the respiratory tract and may even result in instances of poisoning. Some lead compounds are even known to be carcinogenic. Solvent-based paints can irritate the lungs and mucous membranes. Prolonged exposure can affect respiration and the central nervous system. Proper personal protective equipment (PPE) should be worn.

Consult your local industrial health specialist, your local health and safety personnel, and the appropriate MSDS prior to implementing any of these technologies.


Benefits:
  • Higher transfer efficiencies result in significant reductions in both paint usage and waste generation.
  • Less maintenance is required for pollution control equipment serving the painting area.
  • Paint solvent waste and emissions can be further minimized by utilizing a paint gun cleaning station and solvent recovery system. The USAF has authorized paint gun cleaning stations for use under Table of Allowance (TA) 480.


Disadvantages:
  • HVLP systems are sensitive to changes in temperature, pressure and air flow rate. The operator must monitor these conditions to ensure that proper transfer efficiencies are maintained.
  • Solvent-based paints (epoxy, lacquer, polyurethane, and oil-based enamels) will require a solvent to adequately clean the spray guns.


Economic Analysis: Costs will vary depending upon specific applications, painting/coating type, paint volume, workpiece specifications, and technique. Generally, HVLP paint spray system equipment costs approximately $1,000 for a gun, hose, and paint pot. Airless or air-assisted airless paint spray systems range from $2,000 to $3,500. Installation costs will also vary, depending upon location.

Assumptions:

  • Gallons of paint applied to surface per year: 5,000 gallons
  • Gallons of paint purchased per year with HVLP system: 10,000 gallons
  • Gallons of paint purchased per year with high velocity spray system: 20,000 gallons
  • Paint procurement cost: $50/gallon Most paints used by the Air Force are two component epoxies or polyurethanes coatings that cost around $100 for a two gallon kit.
  • Transfer efficiency of HVLP gun: 50%
  • Transfer efficiency of high velocity spray system: 25%
  • Labor requirements: The only significant difference in labor between these systems is the maintenance requirements, as there is no difference in painting times.
  • Labor for High Velocity Spray Systems: 400 hours
  • Labor savings for HVLP: 10%
  • Labor rate: $45/hr.
  • Waste paint collected using dry filter system.
  • Dry filter replacement rate: 1.25 dry filters/hour
  • Dry filter disposal cost: $1/filter

Annual Operating Cost Comparison for HVLP Spray Systems and High Velocity Spray Systems

  HVLP Spray Systems High Velocity Spray Systems
Operational Costs:    
Labor: $16,200 $18,000
Paint: $500,000 $1,000,000
Waste Disposal: $450 $500
Total Costs: $516,650 $1,018,500
Total Income: $0 $0
Annual Benefit: -$516,650 -$1,018,500

Economic Analysis Summary

    Annual Savings for HVLP Spray Systems: $501,850
    Capital Cost for Diversion Equipment/Process: $1,000
    Payback Period for Investment in Equipment/Process: Immediate

Click Here to view an Active Spreadsheet for this Economic Analysis and Enter Your Own Values. To return from the Active Spreadsheet, click the reverse arrow in the Tool Bar.


Approving Authority: Approval is controlled locally and should be implemented only after engineering approval has been granted. Major claimant approval is not required.

The HVLP system is the preferred paint system by the Air Force in T.O.1-1-8 for general paint applications. It is authorized in Table of Allowance 480, but authority resides at the local level.


NSN/MSDS:
Product NSN Unit Size Cost MSDS*
HVLP Gun 4940-01-315-8352 ea. $364.76  
HVLP Gun 4940-01-345-2132 ea. $303.00  
Paint Outfit 4940-01-316-2146 ea. (2 gal.) $1,303.98  
Paint Outfit 4940-00-255-8683 ea. (5 gal.) $2,791.00  


*There are multiple MSDSs for most NSNs.
The MSDS (if shown above) is only meant to serve as an example.


Points of Contact: Air Force:
MSgt. Kevin Emerson
351 Hanger Road
Scott Air Force Base, IL 62225
Phone: (618) 256-3661
DSN: 576-3661


Marines:
Ms. Orathai Bulfer
Environmental Affairs Department
Marine Corps Air Station Cherry Point
PSC 8006 MCAS
Cherry Point, NC 28533-0006
Phone: (252) 466-2864
DSN: 582-2864
FAX: (252) 466-2000


Navy:
Mr. Bob Frederickson
Naval Facilities Engineering Service Center, ESC 423
1100 23rd Avenue
Port Hueneme, CA 93043-4370
Phone: (805) 982-4897
DSN: 551-4889
FAX: (805) 982-4832


Vendors: This is not meant to be a complete list, as there are other manufacturers of this type of equipment.

Accuspray, Inc.
23350 Merchantile Rd.
Cleveland,  OH   44122
Phone: (800) 618-6860 
or (216) 595-6860
FAX: (216) 595-6868

Fluid Air Products (Government Distributor)
12834 Gravois Road
St. Louis,  MO   63127
Phone: (314) 729-7000
or (800) 365-7565
FAX: (314) 729-7099Contact: Bob Hunt
Email:  info@fluidair.com

 

ITW Industrial Finishing
195 International Blvd.
Glendale Heights,  IL   60139
Phone: (630) 237-5000 
FAX:  (630) 237-5003
or (630) 237-5011
Customer Service FAX:  (877) 790-6965
Sales & Marketing FAX:  (630) 237-5012
Technical Support FAX:  (888) 246-5732

 

US Air Force Table of Allowance (TA) 480 should be used by Air Force personnel for National Stock Number (NSN), sources of supply and costs.

 

Enviro$en$e Fact Sheet: High Volume Low Pressure Spray Equipment (http://es.epa.gov/program/regional/state/wi/hvlp.html) lists additional vendors and manufacturers.


Sources: The DeVilbiss Co., Maumee, OH 43537
Mr. Vern Novstrup, NFESC, November 1999.



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