Buttweld Concentric Reducers

Applicable Standards

ASME B16.9

Primary dimensional standard for factory-made wrought buttwelding fittings, including Concentric Reducers.

ASME B16.25

Butt-welding end preparation.

ASTM / ASME Material Specifications

Applicable material standards according to the selected material and grade.

ASME B31.3 / B31.1

Process and power piping requirements, where applicable.

NACE MR0175 / ISO 15156

For sour-service applications when specifically required by the project.

ASME Section II

Material requirements where applicable to pressure equipment and project specifications.

Note: ASME B16.28 should not be listed as the primary standard for Concentric Reducers. Current applicable wrought fitting dimensions are covered by ASME B16.9.

Materials

Carbon Steel

ASTM A234 WPB, WPC and applicable WPHY grades including WPHY 42, WPHY 46, WPHY 52, WPHY 60, WPHY 65 and WPHY 70.

Low Temperature Carbon Steel

ASTM A420 WPL3, WPL6 and other applicable grades.

Stainless Steel

ASTM A403 WP304/304L, WP316/316L, WP321/321H, WP347/347H and other applicable grades.

Duplex & Super Duplex

ASTM A815 grades including UNS S31803, S32205, S32750 and S32760.

Alloy Steel

ASTM A234 WP1, WP5, WP9, WP11, WP12, WP22 and WP91.

Nickel Alloys

ASTM B366 and applicable specifications for Nickel 200/201, Monel 400/K500, Inconel 600/601/625/800/825, Hastelloy C276 and Alloy 20.

Copper-Nickel Alloys

Applicable Cu-Ni grades including UNS C70600 and C71500.

Titanium

Applicable titanium grades manufactured to the relevant ASTM specification, including ASTM B363 where applicable.

Material selection is based on operating pressure, temperature, process fluid, corrosion conditions, mechanical requirements and applicable project specifications.

Concentric Reducer Configurations

Standard Concentric Reducer

Large and small ends share the same centerline, providing a symmetrical conical transition.

Seamless Concentric Reducer

Seamless construction for applicable sizes, materials and wall thicknesses.

Welded Concentric Reducer

Welded construction for selected sizes and materials where permitted by the applicable specification.

Fabricated Concentric Reducer

Custom-fabricated reducers for large diameters, heavy wall thicknesses and special configurations.

Design Features

• Common centerline between both pipe ends
• Gradual conical transition between pipe sizes
• Butt-welding ends for permanent piping connections
• ASME B16.9 dimensions where applicable
• Seamless, welded and fabricated construction
• Controlled wall thickness and dimensional tolerances
• Beveled ends according to ASME B16.25 where applicable
• Wide range of material and grade options
• PMI and NDE available for critical services
• Custom dimensions available
• Suitable for vertical and horizontal piping arrangements, subject to system design

Dimensions & Wall Thickness

Standard Concentric Reducer dimensions are manufactured in accordance with ASME B16.9, where applicable.

Available wall thicknesses include:

SCH 5S, 10S, 20, 40S, STD, 80S, XS, 100, 120, 140, 160 and XXS, together with project-specific wall thicknesses.

Ordering dimensions should identify both the large-end size and small-end size, for example:

• 6″ × 4″ Concentric Reducer
• 8″ × 6″ Concentric Reducer
• 12″ × 10″ Concentric Reducer
• 24″ × 16″ Concentric Reducer

For large-diameter, heavy-wall or fabricated reducers, dimensions can be manufactured according to approved engineering drawings.