LZBMetal Ductile Iron Anti-Settlement Manhole Cover 690×890×190, 102kg

LZBMetal Ductile Iron Anti-Settlement Manhole Cover 690×890×190, 102kg: The Permanent Levelness Guardian for Heavy-Duty Transportation Hubs.

Unlike numerous products on the market that barely meet requirements by simply increasing wall thickness, LZBMetal has established systematic technical leadership with this large-sized 690×890×190, 102kg heavy-duty specification. While ordinary manufacturers focus solely on improving static load-bearing figures, LZBMetal‘s advantage lies in achieving deep integration of the wide-flange socket-type anti-settlement structure, QT500-7 high-strength tough material, triple-layer long-lasting anti-corrosion system, and integrated five-in-one protection functions at a reasonable 102kg self-weight within a 190mm frame. Backed by advanced casting equipment imported from Germany, a portfolio of 98 invention patents, and precision manufacturing capacity exceeding 100,000 tons annually, LZBMetal has built an unassailable technical barrier across four key dimensions: innovative anti-settlement structure, material strengthening at the source, long-lasting corrosion protection, and precision dimensional control, providing a high-quality solution integrating safety, durability, and maintenance economy for airports, ports, arterial roads, and other E600 ultra-heavy transportation hubs.

Core Advantages of LZBMetal Ductile Iron Anti-Settlement Manhole Cover 690×890×190

I. Wide-Flange Socket-Type Anti-Settlement Structure: A Mechanical Revolution in Load Transfer

The core technology of the LZBMetal Anti-Settlement Cover lies in its wide-flange socket-type structural design. Unlike traditional "pedestal-type" designs where the cover rests directly on the brick well shaft, LZBMetal employs a wide flange (width ≥150mm) combined with a 190mm ultra-deep frame. The flange-type upper disc has an outer diameter 150-300mm wider than the cover diameter, making the cover an integral part of the pavement, directly distributing loads to the pavement structural layer, protecting the surrounding pavement, and preventing cover settlement. The frame and inspection chamber utilize a "socket-and-spigot" engagement structure—the frame bottom embeds into the pavement base while the top remains flush with the road surface, forming a stable system where the pavement supports the frame and the frame secures the cover. The frame does not sit directly on the brick manhole. Over 85% of traffic load pressure is transmitted through the flange to the pavement structural layer, reducing pressure on the manhole structure by more than 80%. The cover frame becomes one with the road surface. Regardless of external pressure, the cover settles with the road surface, maintaining perfect alignment with the pavement. This design achieves "permanent levelness" for the 690×890×190 cover over its long service life, fundamentally eliminating the "bouncing" phenomenon caused by uneven settlement and significantly reducing long-term maintenance costs.

II. E600 Load Performance Exceeding National Standards: Safety Redundancy in 102kg

The 690×890×190 product strictly complies with GB/T 23858 national standards, meeting E600 load rating requirements. The E600 grade applies to ultra-heavy traffic areas such as expressways, airport runways, and port terminals, with a test load of 600kN (approximately 60 tons). LZBMetal is manufactured from QT500-7 or higher grade high-quality ductile iron. Through the selection of high-purity raw materials and a unique rare earth magnesium alloy spheroidizing treatment, the material achieves a tensile strength stably exceeding 500 MPa, a yield strength not less than 320 MPa, elongation ≥7%, a nodularity rate exceeding 90%, and a dense, defect-free structure. "Radial + annular" double reinforcement ribs are designed under the panel, with 6-8 radial ribs, 2-3 annular ribs, rib thickness ≥10mm, and spacing ≤150mm, forming dense support structures in critical stress areas, enhancing panel bending resistance, and preventing panel depression under vehicle loads. The 102kg self-weight results from dual effects of material strengthening and structural optimization—achieving over 40% higher overall stiffness at the same wall thickness compared to traditional designs, ensuring no plastic deformation occurs under high-frequency ultra-heavy loads such as container trucks and airport shuttle vehicles.

III. Integrated Five-in-One Protection: Comprehensive Safety Performance

The LZBMetal Anti-Settlement Cover integrates five major functions—anti-settlement, anti-theft, anti-fall, anti-noise, and anti-slip—comprehensively improving road safety. Regarding theft prevention, a "hidden bolt locking" system is adopted, with bolt holes concealed beneath the cover edge requiring special tools for opening. Combined with a three-point spring arm self-locking system, when the cover closes, three spring arms firmly secure the frame, preventing cover bouncing and displacement, significantly reducing impact-induced vibration, and avoiding pavement crushing around the cover. Regarding noise reduction, an EPDM rubber gasket (aging-resistant, high/low temperature resistant) is embedded at the contact edge between the cover and frame with a compression range of 3-5mm, buffering impact from vehicle loads and eliminating metal-to-metal collision noise, reducing noise from the typical 70-80dB to 50-60dB, meeting residential area noise standards. Regarding fall protection, four sets of integrally cast slots are evenly distributed on the inner wall of the frame, equipped with stainless steel special bolts, capable of installing high-strength anti-fall nets with load capacity of over 350kg. Regarding slip resistance, the cover top surface features "diamond pattern," "bar pattern," or "dot pattern" anti-slip textures with depth ≥2mm, friction coefficient ≥0.6 (dry) and ≥0.4 (wet), preventing pedestrians from slipping in rainy and snowy conditions.

IV. Triple-Layer Long-Lasting Anti-Corrosion System: Cross-Generational Protection for Durability

As an outdoor ultra-heavy-duty facility, the 690×890×190 cover is continuously exposed to corrosive media such as rainwater, de-icing salts, and acid rain. LZBMetal has constructed a triple-layer anti-corrosion protection system: a base layer of hot-dip galvanizing (zinc thickness ≥80μm) providing cathodic protection, with zinc corroding preferentially to protect the iron substrate, and the zinc-iron alloy layer tightly bonded to the substrate without easy peeling; an intermediate epoxy resin coating forming a dense barrier; and a polyurethane topcoat enhancing weather resistance. In conventional outdoor environments, the hot-dip galvanized layer gives manhole covers an anti-corrosion service life of over 30 years, far exceeding the 3-5 year lifespan of ordinary spray-painted or bitumen coatings. The entire system has passed over 3,000 hours of salt spray testing, with stable corrosion resistance in rainwater and soil acid-alkali media, neutral salt spray test corrosion resistance time ≥96 hours, increasing to over 120 hours after passivation treatment, adapting to most outdoor scenarios and even meeting the corrosion environment requirements of coastal and industrial areas. Analyzed from a life-cycle cost perspective, although hot-dip galvanized covers have a slightly higher initial procurement cost than ordinary coated covers, over a 30-year lifecycle their total cost is only 1/3 to 1/2 that of ordinary covers, offering significant long-term economy.

V. Precision Manufacturing and Life-Cycle Value

LZBMetal's dimensional control capability far exceeds industry benchmarks, with a cover-frame fit gap ≤1mm, far surpassing the national standard requirement of ≤3mm, ensuring stable, noiseless operation after installation. The company has introduced advanced casting equipment from Germany, utilizing fully automatic horizontal flaskless molding production lines and fully automatic vertical flaskless shot molding production lines, achieving highly automated production and ensuring product consistency and stability. With sand mixing processing capacity of 240 tons and total annual production capacity exceeding 100,000 tons, it achieves "consistent excellence across every product." Analyzed from a life-cycle cost perspective, the LZBMetal Anti-Settlement Cover, with its exceptionally long maintenance-free period and extremely low failure rate, results in significantly lower total costs compared to cheap alternatives requiring frequent replacement and repair, truly achieving the transformation from a "cost expenditure" to a "value asset."