Various coating source specific rules in the South Coast AQMD Rules and Regulations require coatings and adhesives to be applied by specified methods such as electrostatic spray, high-volume, low-pressure (HVLP) spray, roll coater, flow coater, dip coater, etc. in order to maximize the transfer efficiency. Transfer efficiency is typically defined as the ratio of the weight of coating solids adhering to an object to the total weight of coating solids used in the application process, expressed as a percentage. When it comes to spray applications, the rules typically require the use of either electrostatic spray equipment or HVLP spray equipment. Other coating application methods that have been demonstrated to the South Coast AQMD to be capable of achieving either 65 percent transfer efficiency or equivalent or better transfer efficiency than HVLP spray equipment (depending on the source specific rule) can also be used after the Executive Officer has given written approval. 

Transfer Efficiency Test Methods

The South Coast AQMD has developed two documents to assist individuals who want to qualify their spray guns as being capable of achieving 65 percent transfer efficiency or as having equivalent or better transfer efficiency than HVLP spray equipment. Prior to conducting any transfer efficiency testing, a test protocol must be prepared, submitted to the South Coast AQMD with a Plan Application, and approved by the South Coast AQMD.

Test Methods for Spray Gun Manufacturers

Spray gun manufacturers who want to demonstrate that their spray gun is equivalent to HVLP spray equipment must use both the test procedure and the equivalency demonstration guidelines below to demonstrate equivalency.

Guidelines for Demonstrating Equivalency with District Approved Transfer Efficient Spray Guns (PDF, 52kb)

Spray Equipment Transfer Efficiency Test Procedure for Equipment User (PDF, 62kb)

Test Methods for Equipment Users

Equipment users who want to demonstrate that a spray gun is capable of achieving 65 percent transfer efficiency or is equivalent to or better than HVLP must use this document only.

Spray Equipment Transfer Efficiency Test Procedure for Equipment User (PDF, 62kb)

Approval Letters for Spray Guns Deemed Equivalent to HVLP

3M™ Automotive Aftermarket Division Performance Model “P” and Model “2” Spray Gun (Non-Digital) with “Fine Finish” Air Cap 78-8137-4756-1 (Basecoat, Clearcoat, & Primer) (7/23/24) (PDF, 535 kb)

Anest Iwata WS-400-AX-1 Series 2 Spray Gun (Digital and Non-digital) with Air Cap WS-400-01-AX-1 (Clearcoat) (1/31/24) (PDF, 67 kb)

Anest Iwata WS-400 Series 2 Spray Gun (Digital and Non-Digital) with Air Caps WS-400-02, WS-400-02-OBS, WS-400-03, and WS-400-03-BF (4/13/23) (PDF, 80 kb)

Anest Iwata WS-400-AX-1 Non-Digital Spray Gun with Air Cap WS-400-01-AX-1 (4/13/23) (PDF, 70 kb)

Fuji Industrial Spray Equipment Ltd.MPX-30 Spray Gun with 1.4 mm Air Cap Set (4/13/23) (PDF, 62 kb)

Fuji Industrial Spray Equipment Ltd.MP-V8 Spray Gun with 1.3 mm Air Cap Set (4/13/23) (PDF, 62 kb)

Walcom Slim Kombat Spray Gun with Air Cap HTE (5/10/22) (PDF, 395 kb)

Sagola 4600 Xtreme Spray Gun (6/24/21) (PDF, 313 kb)

DeVilbiss Pro Lite Clearcoat Spray Gun with Air Cap TE25 DeVilbiss High Efficiency (9/4/20) (PDF, 80 kb)

DeVilbiss Pro Lite Spray Gun with Air Cap TE10 DeVilbiss High Efficiency (7/21/20) (PDF, 315 KB)

DeVilbiss GPG Spray Gun with Air Cap 7E7 DeVilbiss High Efficiency (7/21/20) (PDF, 313 KB)

DeVilbiss Pro Lite Spray Gun with Air Cap TE20 DeVilbiss High Efficiency (7/21/20) (PDF, 315 KB)

Genesi Carbonio 360 Non-HVLP Spray Gun (2/27/19) (PDF, 64 KB)

ITW DeVilbiss GFG-670 PLUS Spray Gun Approval Letter 9-2-2009 (9/2/09) (PDF, 1362 KB)

DeVilbiss TEKNA PRO and TEKNA PRO LITE TE20 Spray Guns Approval Letter (9/18/18) (PDF, 1747 KB)

DeVilbiss TEKNA 7E7 Spray Gun Approval Letter (9/18/18) (PDF, 1869 KB)

DeVilbiss TEKNA PRO and TEKNA PRO LITE TE10 Spray Guns Approval Letter (9/18/18) (PDF, 1765 KB)

SATAjet X 5500 RP Spray Gun (10/26/18) (PDF, 368 KB)

SATAjet 5000 B RP Revised Approval Letter (10/16/15) (PDF, 565 KB)

SATAminijet 4400 B RP Approval Letter (10/16/15) (PDF, 567 KB)

Satajet 3000 B RP Alternative Approval (7/20/10) (PDF, 381 KB)

Satajet 3000 B RP Alternative Approval (7/21/09) (PDF, 348 KB)

ITW DeVilbiss Alternative Approval (6/2/09) (PDF, 333 KB)

ANEST IWATA (2/26/09) (PDF, 21 KB)  

CVI DeVilbiss (12/9/08) (PDF, 12.7 KB)

GTI Pro DeVilbiss (12/9/08) (PDF, 12.6 KB)

ITW Techna (12/9/08) (PDF, 12.6 KB)

SATA Jet3000 (8/23/06) (PDF, 21.5 KB)

Graco/3M (1/21/05) (PDF, 20 KB)

SATA (11/25/03) (PDF, 21.5 KB)

ITW DeVilbiss (8/9/02) (PDF, 20.5 KB)