Periodic inspection of pressure vessels refers to the conformity verification activity conducted on in-service pressure vessels, carried out by qualified inspection agencies and inspectors in accordance with relevant national laws, regulations, safety technical specifications, and standards (such as the "Special Equipment Safety Law" and "Pressure Vessel Periodic Inspection Rules"), following specified cycles and test methods, typically during downtime. Its core purpose is to timely identify potential safety hazards that may arise during vessel operation due to factors such as corrosion, wear, fatigue, deformation, and material degradation, to evaluate the current safety status of the equipment, to propose scientifically sound treatment recommendations, and to ensure that the equipment remains in a safe and controllable operating condition, thereby fundamentally preventing safety accidents.
Testing Products
Refers to in-service pressure vessels and their associated components that, as defined by regulatory standards, require periodic safety performance verification. This covers:
RD2: Stationary pressure vessels of Classes I, II, and III, excluding ultra-high pressure vessels, large high-pressure vessels, and spherical storage tanks
RD3: Stationary pressure vessels of Classes I and II, excluding spherical storage tanks
Testing Items
Macroscopic (Visual) Inspection:
Visual inspection, using tools when necessary, of the pressure vessel body structure, geometric dimensions, surface conditions (e.g., cracks, corrosion, leaks, deformation), as well as welds, thermal insulation layers, linings, etc.
Wall Thickness Measurement:
Ultrasonic thickness measurement is generally used for wall thickness determination of pressure vessels.
Surface Defect Detection:
Using magnetic particle testing (MT) or penetrant testing (PT) methods.
Buried Defect Detection:
Using radiographic testing (RT) or ultrasonic testing (UT); acoustic emission testing (AET) may be used to evaluate defects when necessary.
Material Analysis:
Depending on the specific circumstances, analysis can be performed using chemical analysis, spectroscopic analysis, hardness testing, metallographic analysis, etc., as required.
Strength Verification:
When conventional methods cannot be used for strength verification, stress analysis or other methods may be employed.
Safety Accessory Inspection:
Mainly includes safety valves, rupture discs, and safety interlock devices for quick-opening pressure vessels.
Pressure Test:
If the user or inspection agency has doubts about the safety condition of a pressure vessel during the periodic inspection, a pressure test shall be conducted.
Leak Test:
Includes tightness testing (air tightness test) as well as ammonia, halogen, or helium leak detection tests.
Testing Standards
Law of the People's Republic of China on Safety of Special Equipment
Regulation on Safety Supervision of Special Equipment (State Council Order No. 549)
Supervision Regulation on Safety Technology for Stationary Pressure Vessel (TSG 21-2016)
Pressure Vessels (GB/T 150-2024)
Non-destructive Testing of Pressure Equipment (NB/T 47013-2015)
Pressure Vessel Periodic Inspection Rules (TSG 21-2021)
Service Advantages
In the field of periodic inspection of pressure vessels, our organization provides full-process, high-quality inspection services for clients across various industries, leveraging a comprehensive qualification system, a professional technical team, and an efficient service model. Our core strengths can be summarized in the following five dimensions, fully meeting the needs of equipment safe operation and enterprise production:
I. Comprehensive Qualification System:
We have obtained a Class B Testing Institution Certificate assessed by the China Special Equipment Inspection Association, and a Special Equipment Class A B1 Inspection Institution Approval Certificate issued by the Shaanxi Provincial Administration for Market Regulation. We are qualified to conduct periodic inspections of pressure vessels (RD2: stationary pressure vessels of Classes I, II, and III, excluding ultra-high pressure vessels, large high-pressure vessels, and spherical storage tanks; RD3: stationary pressure vessels of Classes I and II, excluding spherical storage tanks). We also possess NDT capabilities including RT (including DR), UT, MT, PT, TOFD, PAUT, and ECT.
II. Professional Technical Team:
Our team brings together many industry elites deeply engaged in the field of special equipment inspection and testing, including several senior special equipment inspection experts and young technical leaders. We have dozens of special equipment inspectors and over one hundred NDT personnel, relying on profound professional knowledge and practical experience to provide clients with an exceptional service experience.
III. Advanced Equipment and Methods:
We are equipped with internationally leading testing equipment, totaling over 280 sets, including X-ray flaw detectors, pipe crawlers, digital ultrasonic flaw detectors, phased array ultrasonic flaw detectors, TOFD ultrasonic flaw detectors, DR digital radiography detectors, eddy current detectors, spectrometers, buried pipeline coating detection systems (PCMX), underground pipeline locators (RD8200), close-interval potential (CIPS) survey systems, direct current voltage gradient (DCVG) testing systems, and electronically controlled high-definition endoscopes.
IV. Broad Business Coverage:
Our projects span petrochemical refining, chemical plant installations, coal chemical projects (coal-to-liquid, coal-to-gas, coal-to-methanol, etc.), long-distance transmission pipelines and surface gathering projects (oil and gas transmission), urban pipeline network projects (heating networks, natural gas networks), gas filling station/LPG station pipeline projects, storage projects (spherical tanks, storage tanks, cryogenic tanks), power plant projects, food/pharmaceutical/cement/glass processing/fertilizer/gas manufacturing/military manufacturing plant projects, as well as hotel/hospital projects with self-provided boilers.
The scope of work for the above projects includes third-party or fourth-party NDT and periodic inspection of pressure vessels/pipelines for new construction, repair and maintenance, and in-service inspections. Based on client needs, we also conduct specialized inspections and tests on metallic materials, including spectroscopic analysis (chemical element analysis), hardness testing, metallographic examination, wall thickness measurement, mechanical property testing, and physical property testing. Additionally, we perform annual inspections of pressure pipelines/pressure vessels within the scope of our special equipment inspection authorization, as well as commissioned inspections for equipment exceeding their design service life.
V. Extensive Geographic Coverage:
Our company’s service projects cover multiple provinces and autonomous regions, including Shaanxi, Gansu, Ningxia, Inner Mongolia, and Xinjiang.
