The OTC DAIHEN VRTP400 (S-3) is a highly reputable inverter-controlled DC pulse TIG welding machine (DC TIG) in the market. Thanks to advanced inverter technology, it features an extremely fast dynamic response and a highly stable arc, making it the absolute mainstay for precision welding of stainless steel and carbon steel in industries such as pressure vessels, high-end kitchenware, and medical devices. To accommodate its broad 400A output capacity, the manufacturer offers two standard factory kits: Air-Cooled and Water-Cooled. This article will detail the configuration lists for these two kits and highlight essential piping and cabling points.
1. Welding Expert Guide: Cabling and Piping Differences Between VRTP400 Air-Cooled and Water-Cooled Setups
400A represents a high-power device. The choice of cooling system directly determines the equipment’s endurance and the lifespan of consumables:
- Air-Cooled Configuration (with AW-26 Torch): Suitable for small to medium currents (typically below 200A) or short-seam tack welding. The greatest advantage of the air-cooled system is its extremely simple cabling, requiring only one argon gas inlet hose (P1042K00), providing highly flexible mobility.
- Water-Cooled Configuration (with AW-18 Torch): To unleash the true heavy-duty potential of the VRTP400 (high-current continuous long-seam welding), water cooling is mandatory. Note that the water-cooled configuration includes two more core hoses than the air-cooled one: a Water Inlet Hose (P1042L00) and a Water Return Hose (P1043L00). These two hoses must form a closed loop with an external industrial water chiller to forcefully remove heat from the torch head.
2. OTC DAIHEN VRTP400 Air-Cooled Standard Factory Configuration List (4m Cable)
Application Scenarios: Thin-walled stainless steel sheet metal, pipe fitting tack welding, no external water tank required, highly mobile in the workshop.
| NO. | Core Component Name | Original Model/Spec | Std Qty |
|---|---|---|---|
| 1 | Inverter DC Pulse TIG Welding Power Source | VRTP-400 (S-3) | 1 Unit |
| 2 | Air-Cooled TIG Torch (4m) | AW-26 (4M) | 1 PC |
| 3 | Precision Argon Gas Flow Meter | W-25FL-Ar | 1 Set |
| 4 | Gas Inlet Hose | P1042K00 | 1 PC |
| 5 | Secondary Welding Ground Cable | BKPT-5003 | 1 PC |
3. OTC DAIHEN VRTP400 Water-Cooled Standard Factory Configuration List (4m Cable)
Application Scenarios: High-current continuous heavy-duty machining such as root passes on medium-to-thick carbon steel/stainless steel pipes and pressure vessel seam welding.
| NO. | Core Component Name | Original Model/Spec | Std Qty |
|---|---|---|---|
| 1 | Inverter DC Pulse TIG Welding Power Source | VRTP-400 (S-3) | 1 Unit |
| 2 | Heavy-Duty Water-Cooled TIG Torch (4m) | AW-18 (4M) | 1 PC |
| 3 | Precision Argon Gas Flow Meter | W-25FL-Ar | 1 Set |
| 4 | Gas Inlet Hose | P1042K00 | 1 PC |
| 5 | Dedicated Water Inlet Hose | P1042L00 | 1 PC |
| 6 | Dedicated Water Return Hose | P1043L00 | 1 PC |
| 7 | Secondary Welding Ground Cable | BKPT-5003 | 1 PC |
⚠️ Safety Procurement Warning: The water-cooled configuration (including inlet/return hoses) must be connected to an external industrial circulating cooling water tank. Striking an arc without water circulation is strictly prohibited; otherwise, the internal cables will melt and snap within minutes!


