SX Type SS316L Mixing Element
SX type SS316L crossed-bar mixing element for moderate-viscosity, fibrous, or solids-bearing fluids. DN15-DN300, open geometry minimizes fouling, handles viscosities up to 10,000 cP.
Product Overview
The SX type SS316L mixing element is the open-geometry replacement cartridge for service environments where the helical SK element would foul or plug. The element is built from a stack of crossed rectangular bars — typically 4-6 bars welded to a central tie-rod — with each successive bar layer rotated 45-90° to the next. The resulting lattice gives roughly 70-80% open cross-section, which is high enough to pass fibers, suspended solids up to 5 mm, and viscous fluids that would bridge across the narrower channels of a helical or corrugated element.
Material Properties
SS316L for SX elements is supplied to the same UNS S31603 specification as the SK element — 16-18% Cr, 10-14% Ni, 2-3% Mo, 0.03% C max, 2B finish standard with optional electropolish to Ra ≤ 0.8 μm for pharmaceutical service. The crossed-bar geometry means the bars see bending and shear loads rather than the torsion-dominated loading of the helical element, so the SS316L specification needs to be supplemented by a minimum yield strength of 200 MPa and a Charpy impact value of 60 J at -20°C for the bar stock. The welds attaching the bars to the tie-rod are full-penetration TIG welds using ER316L filler, with dye-penetrant inspection on every element.
Compatible Housings
The SS316L SX element fits the ywmixing SX type housing in DN15-DN300. These housings are flanged (ANSI B16.5 Class 150, DIN PN16, JIS 10K) with a larger bore than the equivalent SK housing, because the open-geometry element needs more clearance at the wall to prevent the outermost bars from creating a stagnant zone. End retention is by a single bayonet lock at each end of the element, which can be released with a flat-blade screwdriver. The element is supplied as a single welded cartridge in all sizes.
Installation & Replacement Guide
The SX element is heavier than the equivalent SK element and typically requires two people to lift in sizes above DN150. Depressurize, drain, and remove the end cover bolts using the standard hex key supplied with the housing. Slide the element out on the integral lifting lug (welded to the upstream end ring). Inspect the housing for fouling deposits; clean with a high-pressure water jet (100-200 bar) if any buildup is visible. Fit new cover O-rings, install the new element, and torque the cover bolts in a star pattern to the specified value. Allow 30-45 minutes total for the replacement in the field, including the cleaning step.
Technical Specifications
| Parameter | Value |
|---|---|
| Material | SS316L (UNS S31603) bar stock, 2B finish, optional electropolish Ra ≤ 0.8 μm |
| Element Geometry | Crossed bars 45°/90° rotation, 4-8 bar layers, central tie-rod |
| Bar Cross-Section | 3×10 mm (DN15-DN50); 4×15 mm (DN65-DN100); 5×20 mm (DN125-DN200); 6×25 mm (DN250-DN300) |
| Open Cross-Section | 70-80% of pipe bore |
| Pipe Diameter Range | DN15 to DN300 |
| Pressure Rating | PN16 standard; PN25 / PN40 available |
| Temperature Range | -50°C to +300°C |
| Viscosity Range | 1 cP to 10,000 cP |
| Particulate Tolerance | Up to 5 mm solid, fibers up to 25 mm length |
| Pressure Drop | ΔP = 0.6-1.2 × empty-pipe ΔP at Re = 1,000-10,000 (lower than SK due to open geometry) |
| Mixing Precision | Coefficient of variation σX ≤ 5-8% at L/D = 5, 6 bars |
| Connection Types | Flange, tri-clamp, weld-neck |
| Mass (DN100, L/D=5) | 2.4 kg per element |
Applications
The SS316L SX element is the standard replacement for solids-bearing, fibrous, or moderately viscous service. Pulp-and-paper mills use the element in stock-chest dilution lines (1-4% consistency pulp at DN100-DN250) where fibers would wrap around a helical element. Municipal wastewater treatment plants use the element in polymer/emulsion blending (cationic polyacrylamide at 0.1-0.5% in raw sewage) where the open geometry prevents the polymer strands from fouling the cartridge. Other typical services include food-processing slurry mixing (tomato concentrate, fruit puree at DN50-DN150), pharmaceutical suspension blending (active ingredient in aqueous vehicle at 5-30% w/w), and chemical plant waste treatment (solvent/water emulsions with up to 5% entrained solids).