Large SK Type SS Mixing Element
Large SK type SS316L mixing element for high-flow industrial service. DN300-DN1000, heavy-duty blade construction, handles 100-2,500 m³/h, used in water intake, flue-gas, and large chemical plants.
Product Overview
The large SK type SS316L mixing element is the heavy-duty replacement cartridge for high-flow industrial service in the DN300-DN1000 range. The element uses the same 180°/270° helical-twist geometry as the standard SK element, but the blade construction is reinforced with a central stiffener rib and the blade thickness is increased to 3-6 mm. The element is supplied in multiple sections (each section 1-2 m long) that are bolted together on site to form a single continuous cartridge. This sectional design keeps each individual piece below 80 kg for crane handling.
Material Properties
SS316L for the large element is the same UNS S31603 specification as the standard element, with a few additions. The plate thickness is 3-6 mm depending on the element size, which requires a mill source capable of rolling plate to that thickness with the same surface finish as the thinner sheet. The welds at the section joints are full-penetration TIG welds using ER316L filler, with radiographic inspection per ASME Section VIII. The section-bolt flanges are SS316L forgings per ASTM A182, with Class 150 or PN16 drilling. Surface finish is 2B as standard, with optional hot-dip galvanizing for outdoor service.
Compatible Housings
The large SS316L SK element fits the ywmixing large SK housing in DN300-DN1000, with flanged (ANSI B16.5 Class 150, DIN PN16) or weld-neck end connections. The housing is supplied in 2-3 sections that are bolted together on site to keep each piece below the 5-ton crane limit. The element is centered in the housing by PTFE or bronze wear-rings at each section joint. End retention is by a bolted flange retainer.
Installation & Replacement Guide
Large SK element replacement requires a crane and two to four technicians. Depressurize, drain, and remove the housing section bolts. Lift the old element out section by section, taking care not to damage the housing bore. Inspect the housing interior and the centering wear-rings; replace any worn rings. Lift the new element sections into place, align the section-bolt holes, and torque the bolts to the specified value. Fit new section gaskets, reassemble the housing, and pressure-test before returning to service. Total replacement time is 4-6 hours, including the crane mobilization.
Technical Specifications
| Parameter | Value |
|---|---|
| Material | SS316L (UNS S31603) plate and forgings, 2B finish, optional hot-dip galvanizing |
| Element Geometry | 180° or 270° helical twist, 2-6 elements per section, 4-8 sections total |
| Blade Thickness | 3.0 mm (DN300-DN400); 4.0 mm (DN500-DN600); 5.0 mm (DN700-DN800); 6.0 mm (DN900-DN1000) |
| Section Length | 1.0 m (DN300-DN500); 1.5 m (DN600-DN800); 2.0 m (DN900-DN1000) |
| Section Mass | 70-80 kg per section (crane-handling limit) |
| Pipe Diameter Range | DN300 to DN1000 |
| Pressure Rating | PN10 standard; PN16 / PN25 available |
| Temperature Range | -50°C to +300°C |
| Viscosity Range | 1 cP to 100,000 cP |
| Flow Rate Range | 100 to 2,500 m³/h |
| Pressure Drop | ΔP = 0.8-1.5 × empty-pipe ΔP at Re = 10,000-100,000 (low) |
| Mixing Precision | Coefficient of variation σX ≤ 5% at L/D = 7, 6 elements |
| Connection Types | Flange (ANSI Class 150, DIN PN16), weld-neck |
| Mass (DN500, L/D=7) | 240 kg total (4 sections × 60 kg) |
Applications
The large SK element is the standard replacement for high-flow industrial service. Power-plant flue-gas desulfurization (FGD) systems use the element in DN800-DN1000 absorbers for limestone-slurry mixing (10-20% CaCO₃ at 5,000-50,000 cP). Municipal water-treatment plants use the element in DN500-DN800 raw-water intake lines for coagulant injection (PACl at 5-15 mg/L). Refinery desalter units use the element in DN300-DN500 wash-water and demulsifier injection lines. Other typical services include pulp-mill brown-stock washing, mining-leachate neutralization, large-volume chemical blending (urea-ammonium-nitrate solution at 200-500 m³/h), and offshore produced-water treatment.