YUHONG GROUP has more than 35 years of experience in supplying pressure vessel materials, heat exchanger components, seamless and welded pipes and tubes, forged products, shells, formed heads, tubesheets, baffles, flanges, and drawing-based pressure-retaining parts in carbon steel, austenitic stainless steel, duplex stainless steel, super duplex stainless steel, alloy steel, and nickel alloys. Our annual sales volume exceeds 80,000 tons, and our products have been supplied to customers in more than 85 countries. Our group companies and manufacturing facilities have obtained applicable international certifications and approvals, including CE, TÜV, LR, ABS, DNV, BV, KR, PED, AD 2000, CCS, TS, CNNC, ISO 9001, ISO 14001, OHSAS 18001, and ISO 45001.
The cylindrical shell forms the main pressure-retaining body of a pressure vessel, shell and tube heat exchanger, reactor, separator, storage vessel, column, condenser, evaporator, or process equipment item. The shell can be supplied as a rolled and longitudinally welded shell course, a multi-course welded shell, or a completed shell assembly with nozzles, reinforcement pads, supports, and internal attachments.
The manufacturing sequence includes material verification, plate cutting, edge preparation, plate rolling or head forming, fit-up, welding, nondestructive examination, heat treatment when required, dimensional inspection, surface treatment, marking, and packing.
Shell longitudinal and circumferential welds are produced according to qualified Welding Procedure Specifications. Welding procedures and welding personnel are qualified according to ASME BPVC Section IX.
Cold or hot forming is selected according to the material grade, plate thickness, component diameter, forming strain, and required finished profile.
| Inspection Item | Requirement | Inspection Method |
|---|---|---|
| Outside Diameter | 89 mm to 10000 mm Manufacturing Range | Diameter Tape or Laser Gauge |
| Starting Plate Thickness | 2 mm to 300 mm Manufacturing Range | UT Thickness Gauge |
| Minimum Finished Thickness | Not Less Than Design Minimum After Forming | UT Thickness Mapping |
| Inside Dish Depth | D Divided by 4 for Standard 2 to 1 Head | Laser Depth Gauge |
| Overall Head Depth | Dish Depth Plus Straight Flange | Laser or Steel Tape |
| Out of Roundness | Controlled to ASME UG 80 and UG 81 | Maximum and Minimum Diameter Check |
| Head Profile | Checked Against 2 to 1 Ellipsoidal Template | Full Size Template or Laser Scan |
| Bevel Angle | 30 Degrees or Project Weld Detail | Bevel Gauge |
| Root Face | 2 mm Typical | Vernier Caliper |
| Surface Defects | No Cracks Harmful Laps or Forming Tears | VT with MT or PT as Applicable |
Pressure vessel shells and ellipsoidal heads are manufactured for:
