Explosion-proof bridge crane quality appraisal

explosion-proof bridge crane takes the core principle of safe coordination of explosion-proof electrical systems and mechanical structures. By optimizing the explosion-proof shell design, motor temperature rise control and mechanical braking redundant system, it achieves high-safety operations in explosive environments. It is widely used in flammable and explosive places such as petrochemical industry, coal mines, and hazardous chemical storage. In petrochemical plants, they are used for hoisting operations in tank areas; underground coal mines to meet equipment transportation needs in methane environments; hazardous chemical warehouses to ensure the safety of material handling in flammable gas environments. Compared with ordinary cranes, explosion-proof bridge cranes have the characteristics of high explosion-proof level, strong mechanical spark suppression ability, and complete fault self-diagnosis system. They are the core equipment for safe production in hazardous places.

Zhongke Testing is a product quality appraisal service organization registered with the court. It can provide quality appraisal services for explosion-proof overhead cranes. It has a professional appraisal team and advanced instruments and equipment to provide fair and accurate appraisal results for the quality appraisal of explosion-proof overhead cranes.

With the popularity of explosion-proof equipment in high-risk industries, related quality dispute cases have become more specialized. Judicial disputes focus on: 1. Disputes over performance indicators: whether the actual explosion-proof level meets the contract requirements and whether the rated lifting load complies with the technical agreement;

2. Material defects: the explosion-proof shell material has insufficient impact resistance, and the copper-based powder metallurgy composition of the brake friction plate is biased Poor;

3. Workmanship issues: The sealing packing of the motor wiring cavity is not fully filled, and the track welding porosity exceeds the standard, causing structural cracks;

4. Contract performance dispute: key components do not comply with the technical agreement.

Such cases need to pass explosion-proof performance testing, material mechanics analysis and structural non-destructive testing to clarify the quality responsibility.

The technical methods for quality appraisal of explosion-proof overhead cranes mainly include:

1. Visual inspection: Check whether there are obvious defects in the appearance of the crane, such as deformation, cracks, rust, etc.

2. Dimensional measurement: Measure the key dimensions of the crane, such as the thickness of steel structural components, boom length, etc., and compare with the design drawings.

3. Ultrasonic flaw detection: Use ultrasonic technology to detect whether there are internal defects in key parts of the crane, such as cracks, inclusions, etc.

4. Static load test: Load a certain weight and conduct a static load test on the crane to evaluate its load-bearing capacity and stability.

A petrochemical company of the applicant signed an "Explosion-proof Bridge Crane Procurement Contract" with a crane manufacturer of the respondent to purchase one QB-20t equipment for hoisting in the propylene tank area. After 2 months of operation, the crane motor junction box exploded, causing production to be interrupted. The petrochemical company accused the explosion-proof design of defects, and the manufacturer argued that it was caused by operators opening the wiring cavity in violation of regulations.

identification analysis results:

The quality analysis expert group discussed and comprehensively analyzed the relevant information, contract technical agreements, on-site inspection case materials and other data on the "explosion-proof bridge crane", and made the following quality analysis opinions :

The flameproof joint surface gap of the motor wiring cavity involved in the case reached 0.25mm (standard ≤0.15mm), and the sealing filler filling rate was less than 60%; the tensile strength of the motor housing material was only 350MPa (contract requirement ≥400MPa); the main beam welds had unfusion defects (8% of the length).

The appraisal conclusion concluded that the manufacturer failed to control the explosion-proof gap and material strength in accordance with GB 3836 standards, and that structural process defects were the main cause of the explosion accident.

explosion-proof bridge crane quality appraisal report mainly includes the following contents:

1. Client information

2. Appraisal equipment information

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

4. Identification method