ASTM A335 Gr P5 Alloy Steel Studded Finned Tube for Refinery Heating Furnace
ASTM A335 Gr P5 Alloy Steel Studded Finned Tube for Refinery Heating Furnace
Studded Tubes / Pinned Tubes do not use continuous fins. Instead, a large number of needle-shaped (cylindrical) or head-shaped (similar to a nail cap) metal nails are welded onto the outer surface of the base tube through resistance welding and other methods.The core advantage of the studded tubes lies in its ability to provide reliable and efficient heat transfer even under extremely harsh conditions, especially in environments with high-intensity radiant heat, as well as severe scaling and wear.
Base tube material P5 is a grade of standard ASTM A335, A335 covers nominal wall and minimum wall seamless ferritic alloy-steel pipe intended for high-temperature service.
Chemical Composition (%)--max
| Grade | C | Mn | P | Su | Si | Cr | Mo |
| P5 | 0.15 | 0.3-0.6 | 0.025 | 0.025 | 0.50 | 4.00-6.00 | 0.45-0.65 |
Mechanical Properties
| Grade | Tensile Strength,min | Yield Strength (0.2%Offset,min) | Elongation-Longitudinal |
| P5 | 60ksi (415 MPa) | 30ksi (205 MPa) | 30% |
Base Tube Inspections and Tests
| 1.Chemical Composition | |||
| 2.Mechanical Properties | |||
| 3.Flattening Test | |||
| 4.Ultrasonic Test | |||
| 5.Intergranular Corrosion Test | |||
| 6.Hardness Test | |||
| 7.Transverse Tensile Test (only for bimetallic tube),etc. |
Main Application Fields
Core Application: The radiant section of heating furnaces in the oil refining and chemical industries is where the studded tubes are most commonly and importantly used.
Application scenario: In the radiant sections of distillation furnaces, coking furnaces, reforming furnaces in oil refineries, as well as ethylene cracking furnaces in the chemical industry.
In cases where there is severe wear and corrosion of the heat exchanger
Application scenarios: Immersed heat exchange tubes in fluidized bed reactors, flue gas waste heat recovery systems, etc.
A special chemical reactor that needs to enhance heat transfer
Application scenario: Certain types of fixed-bed reactors, or as components within the reactor.
Specifications For Various Types Of Finned Tubes
| Type | Description | Base tube | Fin specification (mm) | ||
| O.D. (mm) | Fin pitch | Fin height | Fin thick | ||
| Embedded | G-type fin tueb | 16-63 | 2.1~5 | <17 | ~0.4 |
| Extruded | Single metal combined metal | 8-51 | 1.6~10 | <17 | 0.2-0.4 |
| Low fin tube t-type fin tube | 10-38 | 0.6~2 | <1.6 | ~0.3 | |
| Bamboo tube corrugated tube | 16-51 | 8.0~30 | <2.5 | / | |
| Wound | l/kl/ll type fin tube | 16-63 | 2.1~5 | <17 | ~0.4 |
| String | String fin tube | 25-38 | 2.1-3.5 | <20 | 0.2-0.5 |
| U-type | U-type tube | 16-38 | / | / | / |
| Welding | HF-welding fin tube | 16-219 | 3~25 | 5~30 | 0.8-3 |
| H/HH type fin tube | 25-63 | 8~30 | <200 | 1.5-3.5 | |
| Studed fin tube | 25-219 | 8~30 | 5~35 | 5-20 | |
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.