ASME B16.9 Forged Stainless Steel Reducer Butt Weld Concentric Eccentric Reducer

Product Specification

Forged Stainless Steel Concentric Eccentric Reducer ASME B16.9 Butt Weld Fitting

1. Product Description

A Stainless Steel Reducer is a pipe fitting used to connect pipes of two different diameters, commonly known as a “reducing coupling” or “size changer.” It is available in two structural types: concentric reducers and eccentric reducers. A concentric reducer has both ends on the same centreline with a symmetrical conical body, suitable for vertical lines or applications requiring centreline alignment. An eccentric reducer has one straight side with offset centrelines and can be supplied as bottom-of-pipe (BOP) or top-of-pipe (TOP) for horizontal liquid lines to prevent air pockets, aid drainage, and reduce solids settling. Common materials include 304, 304L, 316, 316L, 321, 310S, Duplex 2205, and 904L. Reducers can be manufactured by reducing or expanding seamless pipe, stamping, or rolled-and-welded fabrication. Ends can be bevelled, plain, threaded, or press-fit, with surface treatments such as pickling and passivation, mirror polishing, matt finishing, or sand blasting. Products can be manufactured to GB/T, ASME, EN, JIS, and DIN standards, with material certificates, dimensional inspection records, and NDT reports available on request.

2. Applications

Stainless steel reducers are mainly used for transition connections between pipes of different nominal diameters. Typical applications include oil and gas gathering and refining, chemical process media transport, water treatment and potable water systems, hygienic piping in food, beverage, and pharmaceutical plants, auxiliary systems in power generation and shipbuilding, HVAC water systems, and pump suction and discharge lines. Eccentric reducers are often used in horizontal pump suction lines, where BOP installation helps reduce air-pocket formation; concentric reducers are commonly used in vertical lines, gas or steam piping, pump discharge lines, and applications requiring a symmetrical flow field. In hygienic systems, reducers also match equipment connections to main lines and facilitate cleaning and drainage; in high-pressure industrial piping, butt-weld reducers are used for reducing connections in pressure-retaining pipe sections.

3. Advantages

• Corrosion resistance and durability: stainless steel tolerates water, steam, many chemicals, and cleaning/disinfection conditions, supporting long-term continuous operation.

• Reliable pressure capability: butt-weld and forged reducers withstand elevated internal pressure, with precise bevel preparation for field welding.

• Hygienic cleanliness: polished interiors are smooth and continuous, reducing residue buildup and microbial growth to meet food and pharmaceutical hygiene requirements.

• Smooth flow transition: the conical reducing structure promotes gradual velocity change and reduces local turbulence, pressure loss, and erosion risk.

• Strong connection adaptability: butt-weld, threaded, socket-weld, press-fit, and clamp-on options match different pipe materials and site conditions.

• Traceable quality: material certificates, dimensional inspection records, and NDT reports can be provided for project acceptance and quality traceability.

• Wide size range and flexible customisation: size, wall thickness, material, eccentric orientation, end type, and surface finish can be tailored to project requirements.

4. Functions

The core function of a stainless steel reducer is to provide diameter matching, smooth transition, and reliable connection between different pipe sizes. Concentric reducers maintain centreline alignment and are suitable for vertical installation, gas/steam lines, and applications requiring a symmetrical flow field. Eccentric reducers, with one straight side, prevent gas accumulation, promote drainage, and reduce solids settling in horizontal liquid lines, and are commonly used in pump suction piping and slurry systems. Reducers also help control flow distribution, reduce flow disturbance, lower stress concentration, and protect downstream pumps, valves, and instruments.

5. Key Specifications

FAQ

1. Are you trading company or manufacturer ? We are manufacturer ,You can see the certification.

2.How long is your delivery time? Generally it is 5-10 days if the goods are in stock. or it is 15-20 days if the goods are not in stock, it is according to quantity.

3. Do you provide samples ? is it free or extra ? Yes, we could offer the sample for free charge but need pay the cost of freight.

4. What is your terms of payment ? Payment<=1000USD, 100% in advance. Payment>=1000USD, 50% T/T in advance ,balance before shippment.