Round tube fixed trusses are a type of Truss that "focuses on stability and long-term use" in the truss family. They are primarily constructed by welding or bolting together round steel tubes Round Tube Truss to form a fixed frame. Unlike quick-assembly trusses, which are frequently assembled and disassembled, they are more suitable for scenarios requiring "long-term standing with minimal changes" (such as permanent exhibition booths in exhibition halls, fixed sunshade frames in scenic areas, and equipment racks backstage in theaters). Their advantages include a solid structure and strong resistance to wind and wobbling, but their drawback is low flexibility—once installed, they are barely modified. Therefore, it is essential to clarify your usage needs before choosing one. Round tube fixed trusses are mainly divided into two types: "steel" and "aluminum alloy." There is no absolute "better" option; the choice depends solely on scenario suitability:
1. Steel Round Tube Fixed Trusses: Cost-Effective with High Load Capacity
Advantages:
Top-Tier Load Capacity: A single Φ40mm×3mm steel round tube can bear 800–1200 kg when used in a horizontal span of 6m (e.g., for hanging large LED screens or heavy advertising light boxes).
High Cost-Effectiveness: For the same specification, steel trusses are 30%–50% cheaper than aluminum alloy ones, making them suitable for scenarios with limited budgets but high load-bearing requirements.
Applicable Scenarios:
Indoor: Fixed equipment racks backstage in theaters Lightweight Round Tube Truss, and load-bearing racks for equipment in factory workshops. Outdoor: Large advertising billboard frames in scenic areas (5–8m in height), and fixed sunshade shed frames in open-air parking lots Modular Round Tube Truss. Note: For outdoor use, hot-dip galvanizing treatment (coating thickness ≥80μm) is a must—it can withstand 3–5 years of rain without rusting. In coastal areas, an additional anti-salt spray coating must be applied to prevent corrosion from sea breezes.
2. Aluminum Alloy Round Tube Fixed Trusses: Lightweight, Rust-Resistant, and Aesthetically Pleasing
Core Material: 6061-T6 aluminum alloy, with the surface undergoing anodization Structural Round Tube Truss or spray coating (custom colors available).transparent; The round tubes have a diameter of 18–40mm and a wall thickness of 1.5–3mm. Advantages:
Low Maintenance: Aluminum alloy has a natural oxide film, eliminating the need for painting. After being rinsed by rain, it only needs a quick wipe—ideal for scenarios where regular maintenance is not feasible.
Aesthetic Appeal: The combination of round tubes and a matte anodized finish makes them more refined than steel trusses, suitable for places like exhibition halls and shopping malls that prioritize appearance.
Applicable Scenarios:
Indoor: Background frames for permanent exhibition booths in shopping malls Round Tube Fixed Truss, and fixed product display racks in exhibition halls.
Outdoor: Fixed sunshade frames in villa courtyards (3–6m in span), and small fixed advertising frames on pedestrian streets Round Tube Support Truss.
Note: Aluminum alloy has lower load-bearing capacity than steel. When the span exceeds 8m, intermediate support columns must be added (otherwise, it will bend downward), and it is not suitable for hanging heavy equipment.
III. Installation: Make these mistakes, and even the sturdiest truss will start to sway.
The "fixing" of round tube fixed trusses is not just about placing them on the ground randomly—it must follow a proper process. Especially in outdoor scenarios, a single wrong step may pose safety risks:
1. First, Secure to the Ground/Wall: Prevent the Truss from "Standing Unsteadily"
Ground Fixing Truss With Round Tube Structure:
Indoor concrete/tiled floors: Weld a "steel plate base" (200×200×10mm in size) to the bottom of the truss, then use expansion bolts Fixed Round Tube Truss Design to fasten the base to the ground (at least 2 bolts per column) to prevent the truss from tilting.
Outdoor grass/soft ground: First dig a pit 30cm deep, bury the truss columns in it, and pour concrete around them (thickness ≥10cm). Wait 24 hours for the concrete to dry completely before use (otherwise, settlement will occur).Wall Fixing (for wall-mounted frames):
For example, for advertising frames leaning against walls in shopping malls, weld "L-shaped connecting plates" to the side of the truss, then use expansion bolts to fasten the connecting plates to the wall (one connection point every 1.5m). This allows the wall to share part of the weight, reducing the load-bearing pressure on the truss itself.
2. Assembly: Welds Must Be Full, Bolts Must Be Tightened
Welded Type (Permanent Fixing):
A qualified welder is a must. Use CO₂ gas shielded welding (more durable than ordinary arc welding). Weld joints must be "full welds" (the weld metal fills the gap, no missing welds allowed). After welding, use an angle grinder to smooth the weld slag, then apply anti-rust paint (for steel trusses) or repair the oxide layer (for aluminum alloy trusses).
Bolted Type (Semi-Fixed):
Use stainless steel bolts (M8–M12; avoid ordinary iron bolts, which will rust and seize up). Each connection point requires at least 2 bolts. When tightening, use a torque wrench (follow the torque value in the manual, usually 30–50N·m)—do not make them too loose (which causes wobbling) or too tight (which may crack the holes).
3. Add "Diagonal Braces/Tie Bars": The Key to Wind and Wobble Resistance
When the outdoor span exceeds 6m or heavy equipment (≥500kg) is hung indoors, "round tube diagonal braces" must be added to the side of the truss (fixed to the main truss at a 45° angle via welding or bolts). For example, adding 2 diagonal braces in the middle of an outdoor advertising frame with a 10m span can increase wind resistance by 50%.
For tall trusses (height ≥5m), "guy wires" (made of galvanized steel wire, 8–10mm in diameter) must be tied to the top of the truss, with the other end fixed to ground anchors (buried at a depth ≥50cm) to prevent the truss from being tilted by strong winds.
IV. Daily Maintenance: Don’t Ignore It After Installation
Although round tube fixed trusses are "durable," regular inspections are still necessary for long-term use—especially for outdoor ones:
Steel Trusses: Check the weld joints and coating every 3 months. If rust on welds or peeling of the coating is found, scrape off the rust first and touch up with anti-rust paint (apply primer first, then topcoat). Tighten the bolted connections with a wrench every 6 months to prevent loosening due to vibration.
Aluminum Alloy Trusses: Wipe off surface dust every 6 months and check for deformation (use a ruler to measure the span; the difference from the installation size should not exceed 3mm). transparent;If there are dents caused by impact, replace the damaged tubes promptly (do not continue using them, as this will affect load capacity).
Outdoor Trusses: After each heavy rain, check for standing water around the base (standing water can damage concrete or corrode the base)—drain it promptly if found. After snowfall in winter, clear the snow on the truss as soon as possible (the weight of snow will increase the truss load and may bend the tubes).
Wuxi Zhongshengwei Metal Products Co., Ltd.
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