GB/T 31052.1-2014 General Rules for the Inspection and Maintenance of Lifting Equipment: General Requirements and Classification Standards for Inspections

GB/T 31052, “Lifting Machinery—Inspection and Maintenance Procedures,” is a series of standards. Part 1, “General Provisions,” was published and implemented in 2014 and specifies general requirements for the inspection and maintenance of lifting machinery. This standard applies to various types of cranes, including bridge, gantry, tower, and mobile cranes, and serves as the core basis for operating entities to establish equipment inspection and maintenance systems. Krude Heavy Industry customizes inspection and maintenance plans for customers in accordance with this standard to ensure the compliant operation of their equipment.

Framework for a Three-Tier Inspection System

The standard establishes a three-tier system consisting of daily inspections, periodic inspections, and comprehensive inspections. Daily inspections are performed by operators during each shift to check the operating condition of the brakes, wire rope wear and lubrication, the reliability of limit switches, and the operating noise of various mechanisms; if any problems are found, the machine must be shut down immediately and reported for repair. The frequency of periodic inspections is determined by the equipment’s service class—once per quarter for classes A3–A5 and once per month for classes A6–A8. These inspections are performed by maintenance personnel and cover items such as wheel wear, gearbox oil quality, coupler alignment, and electrical insulation. Comprehensive inspections are conducted annually by equipment engineers or commissioned inspection agencies, focusing on main girder camber, cracks in the metal structure, wheel misalignment, and load testing.

This three-tier system has a clear division of responsibilities: operators are responsible for day-to-day safety oversight, maintenance technicians are responsible for periodic technical maintenance, and engineers are responsible for annual comprehensive inspections. The results of each level of inspection are recorded in the operation log, inspection checklist, and comprehensive inspection report, respectively, forming a complete equipment health record. The inspections at each level are interconnected—issues identified during routine inspections should be incorporated into the periodic inspection schedule, and structural problems discovered during periodic inspections should be prioritized for re-inspection during the comprehensive inspection. If a major safety hazard is identified at any level of the three-tier inspection system, the equipment must be shut down immediately for resolution; operation while the equipment is defective is strictly prohibited.

The core advantage of the three-tier inspection system lies in its comprehensive coverage and multi-level checks. Routine inspections serve as the safety baseline, periodic inspections constitute preventive maintenance, and comprehensive inspections provide an in-depth assessment. All three are indispensable and complement one another. Operating units should develop corresponding inspection plans and procedures based on their equipment types and operational levels, clearly defining the specific items, standards, and record formats for each level of inspection. For newly installed or overhauled cranes, a comprehensive inspection should be conducted before they are put into service to establish a baseline for their initial technical condition.

Inspection Item Categories

The standard classifies inspection items into three categories: Category A (safety devices), Category B (major load-bearing structural components and mechanisms), and Category C (general items). Category A items must be inspected at every inspection and include hoist height limiters, trolley travel limiters, overload limiters, wind-proof devices, and emergency power-off switches. Category B items are inspected during periodic and comprehensive inspections and include the main girder, end beams, outriggers, wheels, brakes, gear reducers, and wire ropes. Category C items are general inspection items and include lubrication, fasteners, lighting, and signaling devices.

If a Class A safety device fails inspection, it must be shut down immediately for corrective action, as defects of this type directly endanger personal safety. For Class B items, use may resume only after corrective action has been taken, such as welding repairs, replacement, or reinforcement. For Class C items, corrective action may be completed before the next inspection, but the issues must be documented and a maintenance plan scheduled. The standard sets forth clear requirements for the inspection methods, evaluation criteria, and corrective actions for each category. Inspectors must strictly adhere to the standard and must not lower the standards or rely on experience alone when making judgments.

The specific acceptance criteria for Class A safety devices are as follows: The limit switch must operate accurately and reliably; after the switch opens, the hook or trolley must automatically stop at a distance of no less than 200 mm from the limit position. The overload limiter shall reliably activate an alarm and cut off the hoisting power supply when the rated load of the 110% is reached. The wind-resistant rail clamp or anchoring device shall operate smoothly and, once clamped, be capable of withstanding wind loads generated by the maximum local wind speed. The emergency power-off switch shall be capable of cutting off the crane’s main power supply and shall be self-locking, resettable only manually. The undervoltage protection device shall prevent the crane from starting automatically after power is restored; the start button must be pressed again before operation can resume.

Inspection Records and Retention Requirements

Records of daily inspections shall be entered into the equipment operation log and retained for at least one year. Records of periodic inspections shall be filed in the form of inspection checklists and retained for at least three years. A formal inspection report must be issued for comprehensive inspections and filed in the equipment’s technical records, where it must be retained until the equipment is decommissioned. The report must include the inspection items, results, identified issues, corrective actions, and the inspector’s signature. Records must be accurate, complete, and legible; they must not be altered. If corrections are necessary, they must be stamped with a correction seal and signed.

Operating units shall establish technical files for each piece of equipment, with one file per crane. These files shall include manufacturing documentation (factory certificates of conformity, drawings, manuals, etc.), installation and acceptance documentation, daily operation records, periodic inspection records, repair and maintenance records, modification records, and accident records. Equipment records shall be transferred along with the equipment. Records management personnel shall periodically verify the completeness of the records to prevent any missing entries. The use of digital equipment management systems is encouraged, with all inspection records archived electronically to support multi-dimensional searches by time, project, and personnel.

Inspection records serve as a crucial basis for accident investigations and the determination of liability. If a safety accident occurs during the operation of lifting equipment, complete inspection records can help the accident investigation team trace the technical condition of the equipment prior to the accident and determine whether potential hazards were identified and addressed in a timely manner. Therefore, the completeness, authenticity, and traceability of these records are of the utmost importance. It is recommended to use standard-format inspection forms. After completing an inspection, the inspector should sign to confirm the results, and a supervisor or safety manager should review and countersign the form, thereby establishing a comprehensive system for tracking inspection history.

Inspector Qualifications and Training Requirements

The standard sets different qualification requirements for personnel conducting Level 3 inspections: Routine inspections are performed by operators, who must hold a Special Equipment Operator Certificate (Q2 Certificate) and be familiar with the equipment’s structure, performance, and safe operating procedures; Periodic inspections are performed by maintenance technicians, who must have experience in mechanical and electrical maintenance, hold the appropriate Special Equipment Operator Certificate, and be familiar with the adjustment and replacement procedures for all crane mechanisms; Comprehensive inspections shall be conducted by equipment engineers or by a qualified third-party inspection agency. Personnel conducting comprehensive inspections shall hold a professional technical title at the intermediate level or above and have undergone specialized training in crane inspection.

Operating units shall conduct regular training and evaluations for inspection personnel. Training content shall include studying standards and procedures, hands-on practice of inspection methods, use of testing instruments, fault diagnosis, and safety precautions. Daily inspection training for operators should be organized by the equipment management department once per quarter; periodic inspection training for maintenance technicians should be conducted once every six months; and comprehensive inspection personnel should participate in no fewer than 24 academic hours of professional training annually. Personnel who fail the training assessment shall not be permitted to perform inspection work independently. The operating entity shall establish training records for inspection personnel, documenting the training dates, content, and assessment results.

Three-Tier Inspection System Comparison Chart

The following comparison table summarizes the key differences in the frequency, personnel, items, and record-keeping requirements for daily, periodic, and comprehensive inspections, to assist the equipment management department in developing inspection plans and training programs.

Frequently Asked Questions