Petrochemical Fastening Solutions
Petrochemical plants process crude oil and natural gas into numerous chemical products. These facilities require fasteners that can withstand aggressive chemicals, high temperatures, and cyclic loading conditions.
Equipment Applications
Pressure Vessels
Reactors, separators, columns, drums
Heat Exchangers
Shell & tube, plate exchangers
Process Piping
Flanged connections, supports
Pumps & Compressors
Casing bolts, cover bolts
Valves & Actuators
Body bolts, bonnet studs
Furnaces & Heaters
High temperature bolting
Material Selection by Service
| Service Type | Recommended Materials | Temperature Range |
|---|---|---|
| General Hydrocarbon | ASTM A193 B7, 316 SS | -29°C to 538°C |
| Sulfuric Acid | Alloy 20, Hastelloy C-276 | Up to 200°C |
| Hydrochloric Acid | Hastelloy B-2, Hastelloy C-276 | Up to 100°C |
| Caustic (NaOH) | Nickel 200, Monel 400 | Up to 400°C |
| Chlorine Service | Titanium, Hastelloy C-276 | Up to 150°C |
| Acetic Acid | 316L SS, Titanium | Up to 200°C |
| Ammonia | Carbon Steel, 304 SS | -50°C to 450°C |
| Wet Chlorine/Bromine | Hastelloy C-276, Zirconium | Up to 100°C |
High Temperature Applications
Cracking Units
ASTM A193 B7/B16
Up to 593°C
Thermal cycling
Reforming Units
Inconel 625/718
High temperature hydrogen
Anti-carburization
Coker Units
ASTM A193 B7
Cyclic temperature
Coke formation environment
Corrosion Mechanisms
General Corrosion
Uniform material loss over surface area
Pitting
Localized attack in chloride environments
Crevice Corrosion
Under gaskets, washers, deposits
Stress Corrosion Cracking
Tensile stress + corrosive environment
Sulfidation
High temperature sulfur attack
Hydrogen Attack
High temperature/pressure hydrogen
Process Fluid Compatibility
| Chemical | Carbon Steel | 316 SS | Duplex 2205 | Hastelloy C-276 |
|---|---|---|---|---|
| Sulfuric Acid | Poor | Fair | Good | Excellent |
| Hydrochloric Acid | Poor | Poor | Poor | Excellent |
| Caustic (NaOH) | Excellent | Good | Fair | Excellent |
| Chlorine (Wet) | Poor | Poor | Fair | Excellent |
| Seawater/Brine | Poor | Good | Excellent | Excellent |
Industry Standards
- ASME B31.3: Process Piping Code
- ASME Section VIII: Pressure Vessel Code, Div. 1 & 2
- API 660: Shell and Tube Heat Exchangers
- API 610: Centrifugal Pumps
- API 617: Axial and Centrifugal Compressors
- NACE MR0175/ISO 15156: Sour Service
- NACE MR0103: Materials for Hydrofluoric Acid Service
Special Requirements
High Purity Service
• Low carbon content (L grades)
• Solution annealed
• Passivated surface finish
• Traceability to heat number
Hydrogen Service
• Nelson curves for material selection
• NACE MR0175 compliance
• Controlled hardness (≤22 HRC for some services)
Low Temperature Service
• Charpy impact testing required
• ASTM A320 grades for -46°C and below
• Fracture toughness verification