ASTM A213 is mainly used for boiler tubes, superheater tubes, and heat exchanger tubes under high temperature and high pressure conditions.

ASTM A269 is mainly used for general service stainless steel tubes where excellent corrosion resistance and dimensional precision are required.

In simple words:

A213 = High pressure + High temperature

A269 = Precision + Corrosion resistance

For most heat exchanger projects, ASTM A213 and ASTM A269 are both commonly used depending on the working condition.

For heat exchanger tubes, most customers prefer:

Min WT (Minimum Wall Thickness)

because it guarantees the minimum wall thickness at every point of the tube, which is more important for pressure resistance and safety.

Ave WT (Average Wall Thickness) means the average thickness is acceptable, but some points may be thinner.

That is why for critical projects like refineries, boilers, condensers, and offshore applications:

Min WT is usually the better and safer choice.

Yes.

DLSS provides:

Seamless U Bend Tubes

with:

• Tight bending radius control
• No cracking in bend area
• 100% Hydro Test
• PMI Inspection
• Dye Penetrant Test (PT)
• Full dimensional inspection

We support:

Straight tubes + U bend tubes + custom radius

according to project drawings.

Yes.

Every tube can be supplied with:

• PMI Report (Positive Material Identification)
• Hydrostatic Pressure Test
• Eddy Current Test (ET)
• Ultrasonic Test (UT)
• Penetrant Testing (PT)
• Dimensional Inspection Report
• Mill Test Certificate (MTC EN10204 3.1 / 3.2)

For special projects, third-party inspection is also available:

SGS / BV / TUV / DNV / ABS / LR

Our normal production lead time is:

20–35 days

depending on:

• Material grade
• Tube size
• Quantity
• U bend requirements
• Testing requirements

For urgent projects, we can also support:

Fastest 7-day production arrangement

for selected sizes and materials.

Yes.

This is one of DLSS’s major strengths.

For urgent shutdowns, maintenance projects, and EPC deadlines, we provide:

• Fast RFQ response
• Priority production arrangement
• Quick technical confirmation
• Fast inspection approval
• Flexible shipment solutions

Because in many projects:

Delivery time is more important than price.

Yes.

We support:

Flexible MOQ

including:

• Small batch trial orders
• Sample production
• First cooperation trial orders
• Distributor market testing orders

We understand that trust starts from the first order.

That is why we prefer long-term cooperation, not only one-time business.

Yes.

We provide:

Custom tube marking + logo customization

including:

• Customer logo
• Heat number
• Standard marking
• Material grade
• Size marking
• Special export identification

This is especially helpful for:

Traders

Stockists

Regional distributors

to strengthen local brand influence.

Our heat exchanger seamless tubes are widely used in:

• Heat exchanger manufacturers
• Condensers
• Boilers
• Refineries
• Petrochemical plants
• Power plants
• Offshore platforms
• Shipyards
• Desalination projects
• Pressure vessel manufacturers

Especially for:

High corrosion

High pressure

High temperature

working environments.

Very simple.

Just send us:

• Tube size
• Material grade
• Standard
• Quantity
• Drawing (if available)

Even if you only have a rough requirement, our engineers can help you confirm the most suitable solution.

Fast RFQ response within 24 hours.