Illustrative high-performance alloy flange and elbow in a process engineering setting

Material grades

254 SMO / UNS S31254 Material Data

254 SMO / UNS S31254 is presented as a material data page for teams assessing seawater and aggressive chloride-bearing media review. It links alloy identity, product-form review, quality records, and application context without presenting an unreviewed service claim as a final material approval.

Technical snapshot

Key details for your specification.

UNS designation

S31254

Alloy family

High-alloy austenitic stainless steel

Selection context

seawater and aggressive chloride-bearing media review

Typical review setting

chloride-critical process, marine, and water treatment systems

Products and size range

Standard scope for a more complete RFQ.

Each material has its own controlled capability record, giving buyers standard dimensional context before final RFQ specification review.

Flanges

Standard dimensional coverage, pressure-class architecture, facing options, and bore review.

ASME B16.5: NPS 1/2 through NPS 24

ASME B16.47: NPS 26 through NPS 60

Final RFQ confirmation

Butt-weld fittings

Standard NPS / DN architecture, fitting geometry, schedule or wall, and end preparation control.

ASME B16.9: NPS 1/2 through NPS 48

Final RFQ confirmation

Forged fittings

Socket-weld and threaded fitting architecture with class and end-connection review.

ASME B16.11: NPS 1/8 through NPS 4

Final RFQ confirmation

NPS / DN conversion is controlled centrally. Class, bore, schedule, facing, end connection, and RTI capability are reviewed together in the RFQ.

Request custom size

Controlled size architecture

Flange size / class matrix

NPS 1/2 through NPS 24 under ASME B16.5. Standard dimensions are shown for specification planning; availability, manufacturing route, and delivery are confirmed against the final RFQ specification.

Final RFQ confirmation

Class / schedule scope

Classes 150, 300, 400, 600, 900 and 1500. Class 2500 requires the applicable NPS and current governing table to be checked.

Facing / end scope

RF / RTJ as applicable

ASME B16.5 flanges nominal size and configuration guide
Nominal size	DN	Product	Standard	RFQ review
1/2"	DN 15	Flange	ASME B16.5	Final RFQ
3/4"	DN 20	Flange	ASME B16.5	Final RFQ
1"	DN 25	Flange	ASME B16.5	Final RFQ
1-1/4"	DN 32	Flange	ASME B16.5	Final RFQ
1-1/2"	DN 40	Flange	ASME B16.5	Final RFQ
2"	DN 50	Flange	ASME B16.5	Final RFQ
2-1/2"	DN 65	Flange	ASME B16.5	Final RFQ
3"	DN 80	Flange	ASME B16.5	Final RFQ
4"	DN 100	Flange	ASME B16.5	Final RFQ
5"	DN 125	Flange	ASME B16.5	Final RFQ
6"	DN 150	Flange	ASME B16.5	Final RFQ
8"	DN 200	Flange	ASME B16.5	Final RFQ
10"	DN 250	Flange	ASME B16.5	Final RFQ
12"	DN 300	Flange	ASME B16.5	Final RFQ
14"	DN 350	Flange	ASME B16.5	Final RFQ
16"	DN 400	Flange	ASME B16.5	Final RFQ
18"	DN 450	Flange	ASME B16.5	Final RFQ
20"	DN 500	Flange	ASME B16.5	Final RFQ
22"	DN 550	Flange	ASME B16.5	Final RFQ
24"	DN 600	Flange	ASME B16.5	Final RFQ

This table records nominal standard scope, not a promise that every type, class, facing, bore, or material combination is available.

Use the RFQ selector to state product form, NPS / DN, class or schedule, facing or end connection, testing, and documents for review.

Controlled size architecture

Butt-weld fitting size / schedule matrix

NPS 1/2 through NPS 48 under ASME B16.9. Standard dimensions are shown for specification planning; availability, manufacturing route, and delivery are confirmed against the final RFQ specification.

Final RFQ confirmation

Class / schedule scope

Schedule or wall thickness as specified for the fitting geometry

Facing / end scope

Butt-weld bevel

ASME B16.9 butt-weld fittings nominal size and configuration guide
Nominal size	DN	Product	Standard	RFQ review
1/2"	DN 15	Butt-weld fitting	ASME B16.9	Final RFQ
3/4"	DN 20	Butt-weld fitting	ASME B16.9	Final RFQ
1"	DN 25	Butt-weld fitting	ASME B16.9	Final RFQ
1-1/4"	DN 32	Butt-weld fitting	ASME B16.9	Final RFQ
1-1/2"	DN 40	Butt-weld fitting	ASME B16.9	Final RFQ
2"	DN 50	Butt-weld fitting	ASME B16.9	Final RFQ
2-1/2"	DN 65	Butt-weld fitting	ASME B16.9	Final RFQ
3"	DN 80	Butt-weld fitting	ASME B16.9	Final RFQ
4"	DN 100	Butt-weld fitting	ASME B16.9	Final RFQ
5"	DN 125	Butt-weld fitting	ASME B16.9	Final RFQ
6"	DN 150	Butt-weld fitting	ASME B16.9	Final RFQ
8"	DN 200	Butt-weld fitting	ASME B16.9	Final RFQ
10"	DN 250	Butt-weld fitting	ASME B16.9	Final RFQ
12"	DN 300	Butt-weld fitting	ASME B16.9	Final RFQ
14"	DN 350	Butt-weld fitting	ASME B16.9	Final RFQ
16"	DN 400	Butt-weld fitting	ASME B16.9	Final RFQ
18"	DN 450	Butt-weld fitting	ASME B16.9	Final RFQ
20"	DN 500	Butt-weld fitting	ASME B16.9	Final RFQ
22"	DN 550	Butt-weld fitting	ASME B16.9	Final RFQ
24"	DN 600	Butt-weld fitting	ASME B16.9	Final RFQ
26"	DN 650	Butt-weld fitting	ASME B16.9	Final RFQ
28"	DN 700	Butt-weld fitting	ASME B16.9	Final RFQ
30"	DN 750	Butt-weld fitting	ASME B16.9	Final RFQ
32"	DN 800	Butt-weld fitting	ASME B16.9	Final RFQ
34"	DN 850	Butt-weld fitting	ASME B16.9	Final RFQ
36"	DN 900	Butt-weld fitting	ASME B16.9	Final RFQ
38"	DN 950	Butt-weld fitting	ASME B16.9	Final RFQ
40"	DN 1000	Butt-weld fitting	ASME B16.9	Final RFQ
42"	DN 1050	Butt-weld fitting	ASME B16.9	Final RFQ
44"	DN 1100	Butt-weld fitting	ASME B16.9	Final RFQ
46"	DN 1150	Butt-weld fitting	ASME B16.9	Final RFQ
48"	DN 1200	Butt-weld fitting	ASME B16.9	Final RFQ

Elbows, tees, reducers, caps, returns, and stub ends do not share identical dimensional availability. Confirm the exact fitting geometry before quotation.

Use the RFQ selector to state product form, NPS / DN, class or schedule, facing or end connection, testing, and documents for review.

Engineering discussion

Context before component selection.

Engineering context

254 SMO should be reviewed against the actual service definition rather than selected by alloy-family shorthand. The published material data supports high-level material identification and selection context; the supplied lot is accepted only against the purchase standard, material certificate, and approved project requirements.

Specification controls

For 254 SMO / UNS S31254, the RFQ must turn S31254 into a defined material, product-form, dimensional, inspection, document-release, quantity, packing, and delivery record. This avoids using a general alloy or product label as an unapproved technical conclusion.

Procurement decision

Before issuing an order for 254 SMO / UNS S31254, reconcile High-alloy austenitic stainless steel with the drawing or piping class, standard edition, test plan, acceptance authority, and certificate requirements. Any deviation, alternative material, or added test is a project engineering decision.

Standards and release

Define the basis, then document it.

Product-form route

Project-specific product-form standard to be confirmed against the purchase specification

Flange dimensions

ASME B16.5 or the approved drawing basis

Fitting dimensions

ASME B16.9 or ASME B16.11 where applicable

Applications and next steps

Connect the requirement to the right workflow.

chloride-critical process, marine, and water treatment systems

Specification-led flange packages

Traceable alloy pipe fitting enquiries

Drawing-based process components

Material comparisonCompare material selection factors.Alloy productsReview flange and fitting product routes.Technical RFQPrepare a reviewable request.

Buyer questions

Frequently asked questions.

When is 254 SMO considered during material selection?

254 SMO is considered when the defined service, corrosion mechanism, product form, temperature, pressure, and project standard support the material route. Final selection requires project-specific engineering approval.

What should an RFQ for 254 SMO state?

State UNS S31254, product form, the applicable material and dimensional standards, size, class or schedule, inspection scope, MTC, PMI, documentation, packing, and destination.

How should 254 SMO traceability be checked?

Reconcile the heat number, material identification, product form, ordered standard, MTC, PMI record where specified, permanent marking, quantity, and final document register.

Technical quotation

Turn this guidance into a controlled request.

Capture the material, product form, dimensions, standard, inspection, documentation, packing, and destination requirements for review.

Request Technical Quotation View Technical Guides

254 SMO / UNS S31254 Material Data

Key details for your specification.

Standard scope for a more complete RFQ.

Flanges

Butt-weld fittings

Forged fittings

Flange size / class matrix

Butt-weld fitting size / schedule matrix

Context before component selection.

Engineering context

Specification controls

Procurement decision

Define the basis, then document it.

Product-form route

Flange dimensions

Fitting dimensions

Connect the requirement to the right workflow.

Frequently asked questions.

Turn this guidance into a controlled request.

Have a Technical Requirement?