API Standard Air Cooled Heat Exchanger Forced Draft Plug type for Natural Gas Proccessing

YUHONG GROUP is a leading manufacturer of industrial heat exchange solutions, specialising in supplying high-performance air coolers to the global oil and gas, petrochemical, and FPSO (Floating Production Storage and Offloading) industries. Our products are rigorously designed in strict compliance with API 661 and ASME Section VIII Div. 1 standards, fully optimised for the high-pressure, acidic environments and extreme operating conditions encountered in natural gas processing.

Leveraging advanced manufacturing techniques and stringent quality control systems (compliant with international project specifications including ISO 9001 and MODEC GDM3), our plug-type forced-draft air coolers lead the industry in heat exchange efficiency, structural integrity, and long-term corrosion resistance. These units serve as core equipment in natural gas desulphurisation, dehydration, and liquefaction processes.

Material Advantages, Chemical Composition and Mechanical Properties

1. Heat Exchanger Tubes Recommended Material: ASME SA-213 TP316L (for sulphur-containing natural gas) or SA-179 (for conventional service conditions).

Material Advantages: 316L offers exceptional resistance to pitting and crevice corrosion, while its low carbon content (L-grade) effectively prevents intergranular corrosion post-welding.

Chemical Composition (SA-213 TP316L): Cr: 16.0–18.0%, Ni: 10.0–14.0%, Mo: 2.0–3.0%, C le 0.035%.

Mechanical Properties: Tensile Strength: ≥ 485 MPa Yield Strength: ≥ 170 MPa Elongation: ≥ 35%

2. Header Box - Plug Type Recommended Material: ASME SA-516 Grade 70 (Hydrogen-Induced Cracking Resistant for Sour Service).

Material Advantages: Exhibits excellent low-temperature toughness and weldability.

Hydrogen-Induced Cracking (HIC) treatment for sour service conditions ensures structural integrity in hydrogen sulphide environments.

Chemical Composition (SA-516 Gr. 70): C le 0.27% (thickness-dependent), Mn: 0.85–1.20%, P le 0.025%, S le 0.025%

(MODEC standards typically require S le 0.008%).

Mechanical Properties:

Tensile Strength: 485–620MPa, Yield Strength: 260MPa

3. Fins (Finned Surface) Recommended Material: Aluminium 1060 / 6063 (Extruded).

Material Advantages: Extruded fins are formed by mechanically pressing the base tube and aluminium tube together, fully encapsulating the base tube to prevent moisture ingress at contact points causing electrochemical corrosion, whilst offering extremely low thermal resistance.

Mechanical Properties: Possesses excellent ductility, ensuring no fracture occurs even at extremely high fin densities.

4. Shoulder Plugs Recommended Material: ASME SA-105N or SA-182 F316L.

Material Advantages: Forged material ensures high density, preventing leakage in high-pressure natural gas environments.

Mechanical Properties (SA-105N): Hardness Control: Per NACE MR0175, hardness must be ≤ 22 HRC to prevent sulphide stress cracking (SSC).