Low-Pressure Vessel Fabrication

I. Standards and Specifications (Basic Bases)

Domestic Standards

• GB 150《Pressure Vessels》: General requirements covering the entire process, including design, manufacturing, and inspection.
• GB 151《Heat Exchangers》: Specific requirements for heat exchanger-type pressure vessels.
• TSG 21《Safety Technical  Code for Fixed Pressure Vessels》: Statutory regulatory requirements that must be strictly adhered to.
• GB/T 15704《Steel Forgings for Pressure Vessels》: Requirements for material quality.

International Standards

• ASME Ⅷ《Pressure Vessels》: Widely recognized globally, applicable to exported products.
• EN 13445《Pressure Equipment Directive》: Standard of the European Union.

II. Material Requirements (Core Foundation)

Material Selection

• Common Materials: Q345R (Low-alloy High-strength Steel for Vessels), 16MnR, Stainless Steel (304/316L), Carbon Steel, etc.
• Material Requirements: Must possess good strength, toughness, and weldability, and be accompanied by valid material certificates (quality assurance documents).

Material Inspection

• Incoming Inspection: Verify material certificates, perform spectral analysis, and conduct mechanical property tests.
• Unauthorized Use of Unqualified or Counterfeit Materials is Strictly Prohibited.

III. Manufacturing Equipment and Processes

Main Equipment

• Cutting Equipment: CNC Plasma Cutters, Laser Cutters (to ensure precision of material cutting).
• Forming Equipment: Plate Bending Machines (for rolling cylinders), Head Spinning Machines (for forming heads).
• Welding Equipment: Automatic Welding Machines, TIG Welding Machines (to ensure welding quality).
• Machining Equipment: Lathes, Milling Machines, Drilling Machines (for processing accessories).
• Inspection Equipment: Non-destructive Testing (NDT) Equipment (UT/MT/PT/RT), Hardness Testers, Thickness Gauges.

Key Processes

• Cutting: Precision cutting to avoid material waste.
• Forming: Cylinder rolling and head forming to ensure dimensional accuracy.
• Welding: Strictly execute Welding Procedure Specifications (WPS), adopt multi-layer and multi-pass welding to avoid welding defects.
• Heat Treatment: Eliminate welding stresses and improve material properties (e.g., annealing, tempering).

IV. Personnel Requirements (Necessary Qualifications)

Certificated Employment

• Welders: Must hold a Special Equipment Welding Operator Certificate with a welding scope that covers the products.
• Inspectors: Must hold a Special Equipment Inspector Certificate and be responsible for non-destructive testing and visual inspection.
• Designers: Must possess qualifications in pressure vessel design.
• Managers: Must be familiar with relevant standards and regulations.

Professional Training

• All personnel must receive regular professional training to keep abreast of the latest standards and operating procedures.

V. Quality Control Process

In-process Inspection

• Raw Material Inspection: Verify material certificates and conduct mechanical property tests.
• Cutting Inspection: Check dimensions and groove angles.
• Welding Inspection: Perform visual inspection and non-destructive testing (UT/MT/PT/RT).
• Forming Inspection: Check dimensional accuracy and surface quality.

Final Product Inspection

• Hydrostatic Test: Conducted via water pressure testing or pneumatic testing to verify tightness and strength.
• Air Tightness Test: To check for leaks.
• Visual Inspection: Ensure the surface is free of defects and dimensions meet requirements.

Documentation

• Complete quality certification documents must be issued, including material certificates, welding records, inspection reports, and certificates of conformity.

VI. Safety and Environmental Protection Requirements

Safety Requirements

• Strictly comply with safety operating procedures during manufacturing and ensure the 配备 of safety protection facilities.
• For vessels containing toxic or flammable media, special protective measures must be implemented.

Environmental Protection Requirements

• Welding fumes, wastewater, and waste materials must comply with environmental standards and be properly disposed of.

VII. Certification and Registration

Product Certification

• A Special Equipment Manufacturing License (TS Certification) is required to manufacture pressure vessels.