EN
Fixing Boiler
Periodic inspection of textile fixing vessels: pressurised body, lid seal, safety valve and gauge checks by authorised engineers, with signed reports.
Fixing boiler periodic inspection is the examination and testing, by authorised engineers, of the closed vessels operated at high temperature and pressure in textile finishing plants to fix (set) disperse dyes on synthetic fibres. The vessel body integrity, lid safety and pressure control equipment are assessed to verify the safety of these process vessels in line with statutory standards.
What Is a Fixing Boiler?
A fixing (fiksaj) boiler is a vertical or horizontal loading pressurised textile machine that treats the load under saturated steam pressure around the 130°C band to fix the dye into the fibre after disperse or reactive dyeing. It belongs to the same process family as the jet dyeing machine; the difference is that the load is treated in a closed vessel with a static or gently moving bath. Key inspected components:
- Vessel body, arms and welded joints
- Lid, gasket, radial/axial locking mechanism and safety switch
- Safety valve, pressure gauge, pressure and temperature switches
- Steam generator, heat exchanger and condensate line
- Circulation pump and filter circuits
Periodic Inspection Items
- Body and weld examination: Detection of cracks, corrosion and blistering caused by thermal cycling and chemical attack, with non-destructive testing and thickness measurement at suspect zones.
- Lid and lock test: Functional verification of the mechanical and electrical safety chain that prevents lid opening under pressure, and compression control of the gaskets.
- Safety devices: Safety valve set pressure, gauge calibration and the cut-in points of pressure-temperature limit switches.
- Pressure test: Hydrostatic or tightness test depending on the standard and equipment age.
- Installation connections: Insulation of steam and condensate lines, leak checks and condition of supports.
Legislation and Standards
As pressurised work equipment, fixing vessels are subject to Law No. 6331 and the Work Equipment Regulation. The technical design reference is TS EN 13445, pressure equipment legislation is the 2014/68/EU (PED), and machine safety follows the 2006/42/EC Machinery Directive and TS EN 12609. Unless otherwise foreseen, the periodic control is made at least once a year; the interval is shortened under heavy chemical duty.
Risks and Operator Recommendations
Opening the lid under pressure is the most severe accident scenario in this equipment group; the locking system must always pass a functional test at every inspection. Evaporation of acidic and alkaline baths creates local corrosion at the lid rim and flange feet, so thickness measurement should prioritise these zones. Scale deposition in the steam generator disrupts heat transfer and raises overpressure risk; therefore softened water use and periodic chemical cleaning must be tied into the operating procedure. Operator training on the lid-opening procedure (ensuring zero pressure) is an administrative measure as important as the periodic inspection itself.
Outcome
At the end of the examination, a signed periodic inspection report with the compliance status and recommendations is issued. Fixing boiler inspections are part of our Periodic Inspection of Pressure Vessels service group. For equipment from the same process family, visit our Paint Jet and Steam Boiler pages, or contact us for your programme.
FAQ on Fixing Boiler Inspection
A fixing boiler is a pressure vessel-textile machine run under temperature-pressure in the chemical-fixing and post-dyeing fixation processes of textile goods. High-temperature chemical corrosion, pressure-cycle fatigue and invalidation of the lid lock are the leading risks; hot chemical liquid dumping under pressure is a serious burn-poisoning hazard for the operator. The control focuses on these three lines.
On closed volumes rising above 0,5 bar working pressure, inspection under the Work Equipment Regulation runs at intervals not exceeding one year with the proof at 1,5 times operating pressure. Where chemical-aggressive fluid contact exists on the dye-fix line, the manufacturer calendar may be tighter. Daily lid-seal-indicator checks stay with the operator; they do not replace the engineer examination.
Corrosion-deformation examination of shell and lid gaskets, worn inner lining control; lid lock-pressure block chain, safety valve and gauge calibration; temperature-pressure automation program limits-alarm-cut verification; heating steam jacket-burner connections, chemical dosing-feed line check valves, discharge-filtration and relief hardware; electrical panel-earthing-bonding, ventilation-vapour control, plus working pressure-capacity label (CE) conformity.
Each control closes with a measured, finding-levelled, equipment-based report. Critical findings (lock-free door, dead valve, worn shell) trigger a written out-of-service warning; medium findings get a correction plan and follow-up. Repair-change is repeated with verification proof. Reports live in the OHS file and become the next year's comparison baseline; SDS and ventilation verification join the file for chemical safety.