Alloy 800 Welded Pipe | ASME SB-514 | Tailan Metal

Alloy 800 welded pipe is produced to ASME SB-514, which covers
nickel-iron-chromium alloys in the form of welded, cold-worked and annealed pipe for general corrosive
service and heat-resisting applications. It is the availability and cost alternative to SB-407 seamless
pipe at large diameters and thin wall-to-diameter ratios.

Dual Standard Designation

Specification boundary, please read. SB-514 Scope 1.1 lists three alloys —
UNS N08120, UNS N08800 and UNS N08810 — and does not include UNS N08801
(800H). This page is therefore written on an N08800 basis. If your project specifically calls for 800H
welded pipe, contact us before ordering so the applicable specification and the grade we would supply
can be confirmed in writing.

SB-514 1.2 also states that the specification covers outside diameter and nominal wall shown in ANSI
B36.19, with other dimensions possible provided all other requirements of the specification are met.

Chemical Composition (ASME SB-514, Table 2)

^A Iron shall be determined arithmetically by difference.
^B Alloy UNS N08800: 0.10 max. Alloy UNS N08810: 0.05 to 0.10.
Product (check) analysis variations per Specification B 775 (SB-514 7.2).

Mechanical Properties (ASME SB-514, Table 1)

Size Range

Outside diameter and nominal wall per ANSI B36.19; general requirements per Specification
B 775. Welded pipe is normally ordered where the OD exceeds the seamless mill range or where the
wall is thin relative to the diameter. Send us your NPS and wall list for confirmation.

Manufacturing Route & Heat Treatment

Per SB-514, the pipe is made from flat-rolled alloy by an automatic welding process with
no addition of filler metal. Subsequent to welding and prior to final annealing, the
material is cold-worked either in the weld metal only or in both weld and base metal. The pipe is
furnished with oxide removed; where bright annealing is used, descaling is not necessary. Annealing
temperatures include 2 150 °F (1 177 °C) minimum for N08120 and
2 050 °F (1 120 °C) minimum for N08810.

Inspection & Certification

• Flattening test: the pipe shall withstand flattening without cracking until the
  plate distance is five times the wall thickness, with the weld positioned 90° from the
  direction of the applied flattening force. A transverse guided bend may be substituted at the
  manufacturer’s option.
• Nondestructive test, Category 1: each piece of each lot subjected to one of
  hydrostatic, air-underwater pneumatic, eddy current or ultrasonic.
• Nondestructive test, Category 2: each piece subjected to both a leak test
  (hydrostatic or air-underwater pneumatic) and an electric test (eddy current or
  ultrasonic).
• Grain size: annealed N08120 and N08810 shall conform to average ASTM No. 5 or
  coarser.
• PMI available on request; MTC EN 10204 3.1 standard, 3.2 on third-party witness

Packing & Delivery

Plastic end caps on all sizes; steel frames or wooden crates for large diameters; VCI anti-rust
wrapping. Beveled ends standard for welding; plain ends available.

Applications

Large-diameter process piping in refining and petrochemical plants, furnace and heat-treating piping,
oxidation service lines, chloride-bearing seawater and cooling water systems, FGD and waste-heat lines,
transfer piping where the wall-to-diameter ratio makes seamless uneconomic.

Technical Notes

1. No filler metal, and cold work before the final anneal — these are the two clauses
that define this product. SB-514 requires the pipe to be made by automatic welding with
no addition of filler metal, and requires cold work after welding but before the final
annealing, applied to the weld metal alone or to both weld and base metal. Because there is no filler,
the weld metal chemistry is the base metal chemistry, so corrosion resistance across the weld matches
the parent material and post-weld sensitisation risk drops sharply compared with a filler-added weld.
The cold-work step exists so that weld and base metal respond to the final solution anneal the same way
and so that any micro-defects are closed by deformation. A project document that says “welded
with filler” conflicts directly with this specification, so state the requirement explicitly when
you enquire.

2. Weld orientation during the flattening test is the easiest clause to get wrong, and
getting it wrong produces a false pass. The flattening requirement places the weld
90° from the direction of the applied flattening force, which means the weld is
positioned to carry the maximum tensile strain as the pipe is flattened. If the weld is instead aligned
along the flattening direction, the test cannot expose transverse weld defects and the piece passes
without having been meaningfully tested. This is exactly the clause to fix in writing when agreeing an
inspection plan with SGS, TÜV or another third-party inspector, otherwise it becomes a dispute at
the inspection stage.

3. NDT Category 1 or Category 2 is a commercial decision that gets made by default if you
ignore it. Category 1 requires one of four methods per piece; Category 2 requires two per
piece, a leak test plus an electric test, giving substantially fuller coverage. Where the purchase
order does not state a category, SB-514 leaves the selection to the manufacturer. Since Category 1 can
be satisfied by a hydrostatic test alone, leaving the clause unstated means the level of assurance on
a pressure-retaining welded line is effectively set by the supplier. State the required category, and
whether you need eddy current or ultrasonic on every piece, at the enquiry stage.

Frequently Asked Questions

Which ASME specification covers Alloy 800 welded pipe?

ASME SB-514, identical to ASTM B514, Welded Nickel-Iron-Chromium Alloy Pipe. SB-515 covers welded
tube in the smaller OD range and SB-407 covers the seamless form.

Does SB-514 cover UNS N08801 (800H) directly?

Not explicitly. SB-514 Scope 1.1 lists UNS N08120, UNS N08800 and UNS N08810. For 800H welded pipe,
contact us so the applicable specification and the grade we would supply can be confirmed.

Is filler metal used in this welded pipe?

No. SB-514 requires the pipe to be made by automatic welding with no addition of filler metal, so the
weld metal chemistry matches the base metal.

What nondestructive testing is required?

Category 1 requires one of hydrostatic, air-underwater pneumatic, eddy current or ultrasonic per
piece. Category 2 requires both a leak test and an electric test per piece. State the required category
on the order, otherwise the manufacturer selects it.

What is the flattening test requirement?

The pipe must withstand flattening without cracking until the plate distance reaches five times the
wall thickness, with the weld positioned 90° from the applied flattening force.

When should I choose welded over seamless pipe?

Welded pipe is generally more available and economical at large diameters and at thin
wall-to-diameter ratios. For severe corrosion, high-pressure or code-critical service, confirm
acceptability with the design authority before specifying welded in place of seamless.

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