SL Type SS316L Mixing Element
SL type SS316L single-X mixing element for in-line heat transfer and gas blending. DN15-DN250, low pressure drop, ideal for steam injection, tankless water heating, and gas mixing.
Product Overview
The SL type SS316L mixing element is the single-X replacement cartridge used in the SL family of heat-transfer and gas-blending static mixers. The element consists of a stack of crossed flat bars in an X configuration, typically 4-6 bars, with each bar layer rotated 90° to the next. The geometry provides a moderate mixing efficiency (σX ≤ 5-10% at L/D = 5) but an exceptionally low pressure drop (typically 10-30% of the empty-pipe value), which makes the SL element the preferred choice for heat-transfer duty and for gas service where the pressure drop penalty is the dominant cost driver.
Material Properties
SS316L for the SL element is the same UNS S31603 specification as the other stainless elements, with bar stock 2-6 mm thick depending on the element size. The X configuration means the bars see only bending loads (no torsion), which allows the use of higher-strength SS316L bar stock (yield 220 MPa, Charpy 80 J at -20°C) without requiring the more expensive helical-twist geometry. Surface finish is 2B as standard, with optional electropolish to Ra ≤ 0.8 μm for pharmaceutical service.
Compatible Housings
The SS316L SL element fits the ywmixing SL type housing in DN15-DN250, with flanged (ANSI B16.5 Class 150, DIN PN16) or threaded (NPT, BSP) end connections. The housing interior finish matches the element finish. End retention is by a simple split-ring retainer at each end. The element is supplied as a single welded cartridge in all sizes.
Installation & Replacement Guide
The SL element is the lightest of the SS316L elements and can be handled by one person in all sizes. Depressurize, drain, and unbolt the end cover. Pull the element out by the central tie-rod extension, which protrudes 20 mm beyond the upstream end ring. Inspect the housing for fouling; clean with a high-pressure water jet (100 bar) if needed. Fit new cover gaskets, install the new element, and torque the cover bolts to the specified value. Total replacement time is 15-20 minutes.
Technical Specifications
| Parameter | Value |
|---|---|
| Material | SS316L (UNS S31603) bar stock, 2B finish, optional electropolish Ra ≤ 0.8 μm |
| Element Geometry | Crossed flat bars in X configuration, 4-6 bars, 90° rotation |
| Bar Cross-Section | 2×10 mm (DN15-DN50); 3×15 mm (DN65-DN100); 4×20 mm (DN125-DN200); 5×25 mm (DN250) |
| Pipe Diameter Range | DN15 to DN250 |
| Pressure Rating | PN16 standard; PN25 / PN40 available |
| Temperature Range | -50°C to +300°C |
| Viscosity Range | 0.5 cP to 10 cP (gas blending); 1 cP to 1,000 cP (heat transfer) |
| Heat Transfer Coefficient | h = 2-5× empty-pipe value at Re = 10,000-100,000 |
| Pressure Drop | ΔP = 0.1-0.3 × empty-pipe ΔP at Re = 10,000-100,000 (very low) |
| Mixing Precision | Coefficient of variation σX ≤ 5-10% at L/D = 5, 4-6 bars |
| Connection Types | Flange, threaded (NPT, BSP), weld-neck |
| Mass (DN100, L/D=5) | 1.3 kg per element |
Applications
The SS316L SL element is the standard replacement for heat-transfer and gas-blending duty. District heating systems use the element in DN100-DN250 steam-injection water heaters, achieving 95% heat-transfer efficiency in a 2-meter housing. Industrial process heating uses the element in tankless water heaters (5-50 m³/h at 60-80°C). Gas-blending applications include natural gas odorant injection (mercaptan at 1-5 mg/m³ into methane at DN50-DN150), biogas upgrading (CO₂ removal via water scrubbing at DN100), and flue-gas conditioning (NOx reduction via ammonia injection at DN150-DN250). The element is also specified for hot-water recirculation in building HVAC systems, where the low pressure drop allows the use of smaller circulation pumps.