Quality appraisal of steel sliding doors

steel sliding door is based on the core principles of high-strength frame structure and composite sealing technology. By optimizing the profile wall thickness, multi-point locking system and anti-corrosion coating process, it achieves the synergy of wind pressure resistance, air tightness and durability. It is widely used in building curtain walls, industrial plants, commercial spaces and residential buildings. In high-rise buildings, it is used for wind and earthquake-resistant exterior wall door systems; in industrial scenarios, it meets the high sealing requirements of clean workshops; in the civil sector, it ensures the security, anti-theft, and sound insulation of entry doors. Compared with ordinary sliding doors, steel sliding doors have the characteristics of high load-bearing strength, strong weather resistance, and long service life. They are key components for the safety and energy saving of modern buildings.

Zhongke Testing is a product quality appraisal service organization registered with the court. It can provide steel sliding door quality appraisal services. It has a professional appraisal team and advanced instruments and equipment to provide fair and accurate appraisal results for steel sliding door quality appraisal.

With the upgrade of construction safety standards, related quality dispute cases have increased significantly. The judicial dispute focuses on:

1, performance index dispute: wind pressure resistance test failed to meet the standard, air tightness level does not match;

2, material defects: insufficient profile wall thickness, uneven galvanized layer thickness;

3. Process problems: coarse grains in the welding heat-affected zone and insufficient vulcanization of the sealant strips lead to hardening and cracking;

4. Contract performance disputes: the brand of hardware accessories and the anti-theft level of the locks are inconsistent with the technical agreement.

1. Material inspection

uses chemical analysis, metallographic inspection and other methods to determine whether the sliding door material meets the contract or relevant standards.

2. Dimensional measurement

Use tools such as vernier calipers and tape measures to accurately measure the dimensions of the sliding door and compare it with the contract or construction drawings.

3. Surface inspection

The applicant, a commercial real estate company, signed a "High-rise Curtain Wall Sliding Door Procurement Contract" with a door and window factory, the respondent, stipulating that the wind pressure resistance is ≥3000Pa. During the acceptance inspection, it was found that the door leaf was deformed under strong winds, and the manufacturer argued that it was improperly installed.

identification analysis results:

The quality analysis expert group discussed and comprehensively analyzed the relevant information of "Steel Sliding Door", contract technical agreement, on-site inspection case materials and other data, and made the following qualitative analysis Quantity analysis opinion:

The profile wall thickness of the steel sliding door involved in the case is only 1.2mm (agreed 1.8mm), the measured yield strength is 220MPa (Q235B requirement ≥235MPa); the grain size of the welded joint is level 4 (standard ≥level 6), and the hardness of the heat affected zone exceeds the standard (HV 280>Protocol HV 200-250); in the wind pressure test, the door leaf deflection reached L/120 (standard ≤ L/250).

The appraisal conclusion concluded that insufficient material strength and workmanship defects were the main causes of failure.

steel sliding door quality appraisal report mainly includes the following contents:

1. Client information

2. Appraisal equipment information

3. Appraisal basis (standards, power of attorney, etc.)

4. Identification method