Semiconductor / UHP
SEMI F20 gas distribution.
C5 / C10 / C40 for SUS316L VIM/VAR electropolished UHP tubing. Inner-bead oxidation-control targets, controlled particle release, cleanroom-oriented form factor.
Read the methodologySystem family 01 / Closed-chamber
The head that decides high-purity inner beads.
A clamshell chamber, an inert envelope, and a torch that rotates inside it. The C-series is the family for any joint where the inner bead has to survive a SEMI F20-type particle-control review or an ASME BPE-type color/cleanability review. Six heads from C5 to C170 cover 3.175 mm to 168 mm OD on one digital interface.
3.175 - 168 mmOD range across six heads
Oxidation controlSEMI F20-type inner bead target
FXT20Shared digital power source
ASME BPE / SEMI F20Project support
01 / Why the family exists
The closed-chamber problem is shielding, not torch motion.
For high-purity tube-to-tube welds, the inside of the joint is the working surface. Any oxidation, particle release, or out-of-spec weld profile becomes a contamination source downstream - and the contamination doesn't show in the radiograph. It shows in the wafer yield, the WFI conductivity reading, or the brewery's micro test two weeks later.
Open-frame heads can't solve this. They shield the outer surface; the inner surface picks up oxygen the moment the arc strikes. The C-series solves it by enclosing the joint inside a controlled chamber - argon fills the cavity, the torch rotates inside, the inner bead grows in a 360 deg inert envelope.
The six head sizes (C5, C10, C40, C80, C120, C170) cover the full OD range from 1/4" instrumentation tubing to 6.6" process piping. The six heads are specified for the FXT20 power source interface and 200-group program library; per-joint records depend on configuration and project setup.
02 / Six heads, one digital interface
The C-series head matrix.
C5
6.35 - 12.7 mm / 1/4" - 1/2"
Micro head for instrumentation gas lines and analytical tubing.
C10
6.35 - 25.4 mm / 1/4" - 1"
Standard semiconductor UHP and direct-to-chip cooling.
C40
6.35 - 38.1 mm / 1/4" - 1.5"
Water-cooled, larger WFI loops, brewery process piping.
C80
12.7 - 76.2 mm / 1/2" - 3"
Main process piping for biopharma facilities and dairy plants.
C120
19.0 - 114.3 mm / 3/4" - 4.5"
Large diameter sanitary main lines, fermentation circuits.
C170
50.8 - 168 mm / 2" - 6.6"
Largest closed-chamber head, high-volume process loops.
+ FXT20
All six heads
One digital power source covers every C-series head with the same interface and program library.
03 / Engineering specifications
The C-series spec sheet.
Pipe OD range
3.175 mm - 168 mm (1/8" - 6.5")
Wall thickness
0.5 mm - 3.0 mm
Materials
316L / 304L / SUS316L VIM/VAR / titanium / Inconel 625 / chrome-moly
Inner bead
SEMI F20-type oxidation-control target; penetration confirmed by WPS and inspection plan
Shielding gas
Argon 99.999%+ chamber, optional Ar/H / blend for stainless
Cooling
Air-cooled C5 - 10 / water-cooled C40 and above
Cleanroom fit
Cleanroom-oriented configuration; particle requirements confirmed by project QA
Power source
FXT20 digital pulse, shared across all six heads
Data log
Per-joint current / speed / duration / timestamp per FXT20 KB; built-in micro printer
Code fit
SEMI F20 / ASME BPE / EHEDG / 3-A Sanitary / ASME Section IX / AWS D18.1
04 / The shared power source
FXT20 - the compact pulse source for C-series and PT-series.
The FXT20 is the digital pulse-controlled TIG power source FYID-Feiyide engineered specifically for high-purity work. It drives every C-series closed-chamber head and every PT-series tube-to-tubesheet head - same interface, same program library, same firmware.
The FXT20 is designed as a compact digital power source for in-cleanroom retrofit and high-density installation planning. Per-joint data logging is built in, not an accessory.
K-series open-frame work uses a different power source - the industrial-class FXT40 Pro - designed for higher current and field-durability rather than compactness.
Power source
FXT20
Compact digital pulse-controlled TIG power source. Built for FYID-Feiyide C-series closed-chamber and PT-series tube-to-tubesheet heads.
Form factor compact digital power source
Programs on-board 200 groups per FXT20 KB
Duty cycle full-shift duty per rated current
Head compatibility C-series / PT-series
Safety CE EN 60974-1:2012 / M.2025.206.C125225
Programs on-board 200 groups per FXT20 KB
Duty cycle full-shift duty per rated current
Head compatibility C-series / PT-series
Safety CE EN 60974-1:2012 / M.2025.206.C125225
05 / Industry fit
Where the C-series is the right answer.
Biopharma / Food
ASME BPE WFI and sanitary food.
C40 / C80 / C120 for 316L sanitary tubing. Per-joint data logging supports FDA cGMP- and ASME BPE-related traceability documentation.
Read the methodologyAI Cooling / HVAC
Direct-to-chip manifold welding.
C10 / C40 / C80 for 316L and CuNi cooling manifolds. FXT20 compactness makes in-rack retrofits viable.
Read the methodology06 / Common questions
What buyers ask about C-series before the quote.
What is the C-series closed-chamber orbital welder?
The FYID-Feiyide C-series is a family of six closed-chamber orbital TIG weld heads (C5, C10, C40, C80, C120, C170) covering pipe OD from 3.175 mm to 168 mm. All six heads share the FXT20 digital power source and parameter library. The family is engineered for high-purity tube-to-tube welds in semiconductor UHP, biopharma WFI, sanitary food, and AI data center cooling applications.
Which industries does the C-series serve?
FYID-Feiyide C-series heads are deployed in semiconductor UHP gas distribution (SEMI F20), biopharma WFI / CIP / SIP piping (ASME BPE), sanitary food and dairy (EHEDG, 3-A), and AI data center liquid cooling (ASHRAE). All four applications require closed-chamber welding for inner bead quality.
Why use closed-chamber instead of open-frame for high-purity work?
Open-frame heads shield the outer surface of the joint with cup-gas flow. The inner surface picks up oxygen the moment the arc strikes. For high-purity applications - semiconductor UHP, WFI loops, sanitary process piping - closed-chamber heads fill the inside of the joint with inert gas, producing inner-bead oxidation control for SEMI F20 and ASME BPE-type projects.
How does the C-series compare to legacy European closed-head welders?
Three concrete differences. (1) FXT20 is a compact digital power source for in-cleanroom retrofits and rack-level installs with tight access. (2) Delivery is confirmed by configuration, production schedule, and logistics. (3) 200 recipe groups give operators controlled starting points for customer WPS development and review.
How quickly can FYID-Feiyide ship a complete C-series + FXT20 configuration?
Delivery schedule is confirmed by configuration, production schedule, inspection requirements, and logistics. Vertically integrated manufacturing in Huanggang, Hubei keeps assembly and inspection under one roof. Remote engineering support can be arranged after equipment arrival.
Send us the joint. We'll come back with C-series head + program list.
Engineering review timing is confirmed by project and timezone. Include OD, wall, material, standard, and target throughput per shift.
Talk to an engineer