ASME SA 249 TP304 welded stainless steel tubes manufacturer in China, we have more than 10 years of experience, TP304 stainless steel tube is welded complying to ASME SA 249 specification, the standard indicate manufacturing process, material, sizes and other conditions, so that welded tubes are produced better for heat exchanger, boiler and condenser system.
TP304 Stainless Steel
TP304 grade is the most widely used Austenite stainless steel, because it has good properties and strong corrosion resistance, it it is also ideal grade to save cost in stainless steel family, TP 304 is typical 18 Chromium 8 Nickel stainless steel, usually, TP304 is also AISI 304, chemical elements and percent composition are mainly listed as below.
Carbon: max 0.08%, Silicon: max 1.0%, Manganese: max 2.0%, Phosphorus: max 0.045%, Sulfur: max 0.030%, Chromium: 18 – 20%, Nickel: 8 – 11%, the balance is iron content.
TP304 stainless steel has good forming and welding features, it can be used many applications, like oil and air, plant, food processing, medical and pharmaceutical field, compared to TP304L and TP316L, TP304 grade is a cost effective stainless steel.
ASME SA 249 specification
ASME SA 249 standard is for welded stainless steel tubes, the tubes are installed for heat changer, boiler and condenser in heating or cooling deliver system. The tube is made starting from stainless steel strip or coil, welding both edges, forming the shape, rolls inside and outside surface, that will be shape tubes, then heat treatment and cold working process should be made conforming to this standard.
ASME SA 249 TP304 Welded Tubes sizes and Dimensions
ASME SA 249 stainless steel heat exchanger, boiler and condenser tubes have various sizes with various grades, outside diameter, wall thickness, as well as length is main size requirement. custom sizes we offered for welded tubes are as below.
Outside diameter: range from 6 to 304.8 mm, custom sizes have 16, 19.05, 25.4, 31.8, 38.1, 44.45, 50.8, 76.2, 101.6 mm
Wall thickness: average thickness and minimum thickness are available, there are 0.71, 0.89, 1.0, 1.25, 1.65, 2.11, 2.77 mm.
Tolerance of outside diameter and thickness should conform to ASME SA 249 specification and ASTM A1016/M, welded tubes require precise tolerance for the specific use.
|＜25.40mm||±0.10mm||±10.00%||OD＜50.8mm +3.0mm -0mm
OD≥50.8mm +5.0 -0mm
Quality Control for SA 249 TP304 Welded Stainless Steel Tubes
Tube analysis should conform to TP304 stainless steel chemical composition, like nickel alloy content and others, using direct-reading spectrometer or PMI tester.
All tubes shall be furnished in the heat-treated condition in accordance with the required solution temperature, TP304 grade solution temperature range is from 1040 ℃ to 1150 ℃, heat number should be recorded according to same size of each lot.
The tubes shall undergo mechanical tests such as tension test, flattening test, flange test, reverse-bend test, hardness test (Rockwell hardness), nondestructive test is conducted for each tube, like eddy current testing and air underwater testing.
Special testing should be stated prior to production, such as intergranular corrosion test, welding decay test.
Mill Test Certificate should be offered according to EN 10204 3.1 type.
ASME SA 249 TP304 Welded Stainless Steel Tubes Conditions
We have complete sets of production lines, including auto welding machines and bright annealed device, production capacity can meet kinds of requirement and additional value service, like U bend welded tube, bright annealing welded tube, cold drawn precision tube.
U Bend Welded Tube
In heat exchanger system, it often requires U bend type stainless steel tubes, U bending tube has benefits to save cost. leg length max 12 meters, radius max 1.5 meters, bending part should be heat treated to relieve stress, thereafter pickling to ensure tube surface clean.
Bright Annealing Tube
Bright annealing and annealed pickling processes can eliminate the scaling to make inside and outside surface clean, inert gas hydrogen air in closed furnace, then heat treatment improve tube roughness, it made tube more brighter, when it is installed in heater and cooler system, that will be easy as well as to clean.
ASME – American society of mechanical engineers
ASTM A249 / A249M – 18
Standard Specification for Welded Austenitic Steel Boiler, Superheater, Heat-Exchanger, and Condenser Tubes