12M Flame Spray Gun Parts

The 12M Flame Spray Gun is one of the most widely used wire flame spray systems in the metal spraying industry, and what makes it truly dependable is its well-engineered internal structure. Each part of the gun has been designed to support smooth metal wire feeding, stable flame control, and consistent coating output. If you operate, service, or sell the 12M Flame Spray Gun, understanding its parts is essential.

In this blog, we break down the complete parts list—based entirely on the official 12M Flame Spray Gun Part List provided by Balaji Udyog 12M FLAME PART LIST.pdf (2). We cover what each component does, how assemblies work, and why each part is important.

1. Air Cap Body & Air Caps

The air cap system controls the airflow around the molten metal stream. According to page 9 of the PDF, the Air Cap Body (12M-1) is the head where all air caps are fitted.

Types of air caps include:

• AH / AHM Non-Load Air Caps

• AM Air Cap

• C / CH Air Caps

• EA, EC, J, JH, M, MH, N Air Caps

• Fan Spray Air Caps (AB, CD)

Each air cap changes the spray pattern, droplet size, and finish quality. For example:

• Fan spray caps create a wide pattern for larger surface areas.

• Non-load caps reduce back-pressure and prevent overheating.

2. Nozzles

Nozzles direct the flame and molten wire stream. Pages 9–11 list a wide range:

By Fuel Type

• Acetylene Nozzles

• Propane Nozzles

• MPS gas Nozzles

By Wire Size

• 3/16”

• 1/8”

• 11 Gauge

• 15–20 Gauge

Load vs Non-Load Versions

"Non-load" nozzles are designed to reduce pressure and maintain stable combustion during high-temperature spraying.

Nozzles are the most frequently replaced item in the spray gun because:

• They experience high heat

• They can clog with molten metal

• They wear out from constant wire friction

3. Siphon Plugs

A key component in maintaining the correct gas flow and flame temperature, the siphon plug mixes oxygen and fuel gas inside the nozzle.

The PDF lists siphon plugs for:

• Acetylene (large & small gauge)

• Propane / MPS

• 3/16”, 1/8”, 11 Ga., 15–20 Ga.

These plugs must match the nozzle and wire type. Using the wrong combination can cause:

• Flame instability

• Poor coating adhesion

• Increased nozzle wear

4. Gas Head Assembly (12M-5)

Shown on page 2, the gas head assembly is one of the most important parts. It regulates the flow of:

• Oxygen

• Fuel gas

• Air

Key internal components include:

• Valve core

• Valve O-rings

• Control handle

• Gas inlet and outlet ports

A properly sealed gas head ensures a clean, stable flame and prevents backfire.

5. Drive Roll Mechanism

The drive system is responsible for feeding the metal wire smoothly towards the flame.

Main Parts (Page 3 & 7):

• Drive Roll Carrier (12M-32)

• Upper Drive Roll (12M-31)

• Lower Drive Roll (12M-33)

• Drive Roll Gears (12M-36, 12M-35)

• Axle Screws (12M-48)

Different drive rolls exist for:

• 3/16”

• 1/8”

• 15–20 Gauge

• 11 Gauge

A worn drive roll leads to:

• Wire slipping

• Irregular spraying

• Flame choking

6. Turbine & Speed Control Assembly

The signature feature of the 12M gun is the air turbine-driven wire feed system.

On page 4 you see:

• Turbine Rotor (12M-59)

• Turbine Cover (12M-77)

• Counter Shaft Assembly

• Drive Shaft

• Speed Control Ring

Compressed air spins the turbine, which rotates the drive rolls. This system is smoother and more durable than electric motors.

A damaged turbine results in fluctuating wire speed, the most common cause of poor coating quality.

7. Snubber Assembly (12M-118)

The snubber assembly (page 5) provides pressure on the wire, preventing it from bouncing or slipping.

It includes:

• Snubber Spring

• Snubber Housing

• Rod & Cover

Different snubber assemblies are available for different wire gauges.

8. Tool Post Fixture & Maintenance Tools

Page 6 lists important tools included with the gun:

• Tool Post Fixture (12M-124)

• Drive Roll Tool

• Spanner Wrench

• Socket Wrench

• Screwdriver

• Nozzle O-Ring Tool

These tools allow operators to:

• Change nozzles

• Adjust drive rolls

• Tighten turbine parts

• Replace O-rings

9. Central Housing & Handle

Page 7 shows the gun’s body, which includes:

• Central Housing (12M-60)

• Handle Assembly

• Gear Cover (12M-56)

• Bearings

• Drive Shaft Seal

This section holds the internal gearing that connects the turbine to the drive rolls.

A strong housing ensures:

• Heat resistance

• Shock absorption

• Long lifetime

10. Bearings, Seals & O-Rings

The gun uses multiple bearings and O-rings, listed across pages 10–14:

Types of Bearings:

• Drive Shaft Bearings

• Turbine Shaft Bearings

• Counter Shaft Bearings

O-Rings:

• Nozzle O-rings

• Valve O-rings

• Siphon plug O-rings

• Gas head O-ring packages

• Plunger O-rings

O-rings maintain airtight and gas-tight seals, which are crucial for safety.

11. Control & Adjustment Parts

The gun includes control components such as:

• Valve Handle Assembly (12M-43)

• Control Ring (12M-66)

• Brake Disc & Spring

• Detent Spring

• Set Screws

These help operators fine-tune:

• Flame intensity

• Wire speed

• Air pressure

12. Safety & Utility Parts

Pages 16–17 list safety accessories:

• Eye protectors

• Hearing protectors

• Shade-5 lenses

• Protective plates

• Tool kit

• Lighter

• Oil lube
  These ensure safe and uninterrupted operation.

13. Complete Assemblies

The PDF also lists complete assembly kits:

• Snubber Assembly (different sizes)

• Siphon Plug Assembly sets

• Gas Head O-Ring Package

• Safety Package

• Complete Metal Spray Gun without spear

• Gun spear parts

These kits make maintenance easier for workshops.

Conclusion

The 12M Flame Spray Gun is built from a complex yet perfectly synchronized system of over 250+ parts. Each part—whether a simple O-ring or a turbine rotor—plays an essential role in ensuring smooth operation, stable flame, and high-quality metal coatings.

By understanding these parts and assemblies, operators can:

• Troubleshoot issues quickly

• Replace components accurately

• Improve spraying performance

• Extend the gun’s lifespan