Flanged Static Mixer

Product Overview

The flanged static mixer is the workhorse structural variant of the ywmixing product line. It consists of a cylindrical shell fitted with mating flanges on each end, containing a removable mixing-element cartridge. The flanged interface allows the entire assembly to be dropped into an existing pipe spool between two flanged connections and bolted in place, exactly like a pipe spool, strainer, or check valve. This is the connection type specified by approximately 70% of our industrial customers because it lets maintenance crews pull the cartridge without cutting the pipe or sending a hot-work crew to the field.

Inside the shell, the customer can specify any of the five mixing geometries (SV corrugated plate, SK helical, SX cross-bar, SH dual-channel, or SL single-X) so the connection style is fully decoupled from the mixing technology. A DN200 SS316L flanged mixer with an SK helical cartridge is one of the most common configurations in chemical dosing skids; a DN600 carbon-steel flanged mixer with an SV corrugated plate is the standard for municipal water treatment. The flanged variant therefore serves as the structural platform for the entire mixer family.

The unit is designed for bolted-service pressure ratings up to PN40 (40 bar) in carbon steel and PN16 (16 bar) in stainless steel, with temperature envelopes from -50°C to +300°C depending on material and gasket selection. Standard sizes span DN15 to DN600, and custom large-bore units up to DN1000 are built to order. Gasket face finishes are RF (raised face) by default, with RTJ (ring-type joint) and FF (flat face) available for special service.

Design Features

The flanged mixer housing is built as a flanged pipe spool with an internal cartridge retainer. The shell is rolled and seam-welded from plate or bar-stock pipe, then fitted with forged or plate-flange weld-necks at each end. The flange facing follows the customer-specified standard, and the bolt pattern is matched to the mating pipe flanges in the plant. A removable retainer ring or shoulder at each end of the shell holds the cartridge in place during operation but allows axial extraction when the downstream flange is unbolted.

The mixing cartridge is a stand-alone assembly that slides into the shell on a precision machined spigot. It carries the mixing elements (helical elements, plate pack, X-bars, or dual-channel core depending on the technology selected), the central alignment key, and the locating shoulders. When the operator unbolts the downstream flange and slides the cartridge out, the elements come with it as one piece — no loose parts, no dropped hardware inside the line. Cartridges are available in 1.4404 (316L), 1.4301 (304), Hastelloy C-276, and PTFE-lined carbon steel.

Gasket seating is machined to a Ra ≤ 1.6 μm finish and uses a spiral-wound graphite/filler gasket rated for the design pressure and temperature. For high-temperature cyclic service (above 200°C with daily start-up/shutdown), we recommend graphite-faced gaskets with a stainless inner and outer ring; for cryogenic service below -30°C, PTFE-jacketed gaskets are specified to retain seal at the reduced bolt load. All flanges are drilled and identified per the customer's piping class.

Pressure-containing components are designed in accordance with ASME B31.3 for process piping or EN 13445 for European installations, with a 1.5× design margin on burst and a 4× margin on fatigue. The housing carries a unique serial number, ASME U-stamp or PED CE-marking where applicable, and full MTR (mill test report) traceability for wetted parts.

Technical Specifications

Parameter	Value
Connection Standard	ANSI B16.5 / DIN PN / JIS / GB / AWWA — Class 150, 300, PN10, PN16, PN25, PN40
Pipe Diameter Range	DN15 to DN600 (custom DN1000 on request)
Pressure Rating	Up to PN40 (carbon steel) / PN16 (SS316L) / PN100 special
Temperature Range	-50°C to +300°C (metallic) / -10°C to +80°C (PTFE-lined)
Housing Material	SS304, SS316L, Carbon Steel SA-106 Gr.B, Hastelloy C-276, Duplex 2205
Cartridge Material	Same as housing, or PTFE/PVDF-lined carbon steel
Mixing Elements	SV / SK / SX / SH / SL — customer selected
Flange Facing	RF (default), FF, RTJ, Tongue & Groove
Gasket Type	Spiral-wound graphite, PTFE, or graphite-clad stainless
Design Code	ASME B31.3, EN 13445, ASME B&PV Sec VIII (vessels)
Certification	PED CE, ASME U-stamp, ATEX on request
Flow Rate Range	0.1 to 4,000 m³/h (size dependent)

Connection Options

Flange standards are configured per the customer's piping class. For North American process plants, the standard is ANSI B16.5 Class 150 (PN20 equivalent) for general service and Class 300 (PN50 equivalent) for high-pressure hydrocarbon service. The flanges are flat-faced or raised-face to match the mating pipe; ring-type joint (RTJ) is reserved for high-temperature refinery service above 400°C.

For European installations, the default is EN 1092-1 PN16 (16 bar at 120°C) in carbon steel with a Type B1 raised face. PN25 and PN40 are built for high-rise water service, chemical injection, and offshore process. The flanges are machined to a 0.2-0.5 mm lip finish for spiral-wound gaskets.

For East Asian projects, JIS B2220 10K (10 bar) and 20K (20 bar) flange drillings are available. Gasket dimensions are per JIS B2404, with non-asbestos fiber or graphite filler. GB/T 9119 (Chinese national standard) flanges are also stocked for export projects into the Chinese domestic market. The bolt pattern and PCD are guaranteed to be interchangeable with the mating pipe spool.

Large-bore flanged mixers (above DN600) typically use ASME B16.47 Series A or AWWA C207 Class D / E flanges, both of which can be supplied on engineered order. For subsea service, the flange is supplied with API 6A or NACE MR0175 compliance, and the wetted materials are restricted to super-duplex 2507 or Inconel 625.

Applications

Chemical injection skids. The flanged mixer is the default for chemical-injection packages on offshore platforms, refinery headers, and well-head skids. The cartridge is accessed during the 6-monthly shutdown, the elements are inspected for fouling, and the unit is returned to service within the same shift.

Municipal water treatment. Flanged SV mixers are used in coagulation and flocculation basins for polyaluminum chloride (PAC) and cationic polymer dosing. The PN16 DIN flange matches the ductile-iron pipework in the plant, and the cartridge retention allows the operator to swap from SV to SK geometry when the raw-water turbidity rises above 500 NTU.

Refinery and petrochemical. Flanged SK mixers are installed in the caustic wash and amine treatment sections of hydroprocessing units, where the SS316L housing and PN40 rating match the high-pressure hydrocarbon service. Cartridge change-out is performed during the 4-yearly turnaround.

Pulp and paper. Flanged SH mixers are used for chlorine dioxide and peroxide blending in bleach plants. The high-viscosity SK variant is also used for stock blending ahead of the headbox. The flanged body matches the standard ANSI Class 150 piping class used throughout the mill.

Power generation. Flanged mixers handle ammonia, hydrazine, and morpholine dosing in the condensate and feedwater systems of fossil and nuclear power plants. ASME-stamped housings are supplied for the nuclear safety-class applications, and the cartridge design allows in-service inspection under the plant's ASME Section XI program.

Frequently Asked Questions

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