Ⅰ. Overview of Transformer Pressure Relief Valve
The pressure relief valve is a core pressure protection component for power transformer equipment. As a fully enclosed power device, the oil filled power transformer will generate massive gas from oil decomposition once internal severe faults such as short circuits occur. Due to the small diameter of the connecting pipe between the transformer tank and the conservator, the conventional pressure relief method relying solely on the conservator cannot release internal pressure rapidly. This will cause a sharp pressure surge inside the tank, leading to tank deformation, cracking or even equipment scrapping. The pressure relief valve solves this problem effectively by opening instantly to discharge a small amount of transformer oil and release excess internal pressure. After the pressure returns to the safe range, the valve automatically closes to restore the tightness of the transformer tank. According to the standard GB/T6451-1999, all power transformers with a capacity of 800 kva and above must be equipped with pressure protection devices, which is a mandatory safety configuration for mainstream power transformer products.
Ⅱ. Working Principle of Pressure Relief Valve
Transformer pressure protection systems mainly include two types of devices: explosion-proof tubes (safety air passages) and pressure relief valves. Traditional explosion-proof tubes adopt a rupture membrane structure, which can only release pressure by breaking the membrane under high pressure and cannot be reused, with poor safety and repeatability. The pressure relief valve is an upgraded replacement product for explosion-proof tubes and is widely used in modern power transformers. Its core structure adopts a spring-compressed diaphragm disc design. When the internal pressure of large-capacity transformers exceeds the spring set pressure, the pressure will push open the diaphragm disc instantly to complete pressure relief. The biggest advantage of this structure is automatic reset and reusable use, which makes up for the defects of traditional explosion-proof structures. In addition, the pressure relief valve is equipped with linkage signal contacts. When power transformers fail and trigger valve action, the contacts will switch signals automatically to realize remote alarm or equipment trip protection, avoiding major power accidents.
Ⅲ. Service Conditions & Installation Specifications
The pressure relief valve features strong environmental adaptability, with a standard operating temperature range of -30°C to +95°C, which can adapt to most outdoor and indoor power operation scenarios. In terms of installation, the valve can be installed on the top cover of the transformer tank or the upper side wall of the tank. For large-capacity units like the 2500 kva transformer, side installation is mostly adopted, and an oil discharge pipe is usually matched at the valve outlet to ensure smooth oil discharge and efficient pressure relief. This flexible installation method is suitable for various specifications of oil filled power transformer units and fully meets the installation and safety operation requirements of industrial power equipment.
Ⅳ. Core Performance Standards of Pressure Relief Valve
To ensure the safe and stable operation of power transformer equipment, pressure relief valves have strict standardized performance indicators, covering opening and closing pressure, response speed, aging resistance and sealing performance. For the oil filled power transformer, these standardized parameters are critical to long-term operational safety and fault resistance.
1. Opening & Closing Pressure Performance
The assembled pressure relief valve must meet the standard opening and closing pressure parameters. For valves with mechanical signal indicators, the indicator rod will act significantly after opening and remain in the open state, requiring manual reset after fault elimination. For valves with signal switches, the contact can realize reliable switching and self-locking after action, with stable signal feedback.
2. Ultra-Fast Response Performance
When the pressure acting on the diaphragm disc reaches the set opening pressure, the pressure relief valve must complete opening action within 2ms. The ultra-fast response can instantly release sudden internal pressure of the 2500 kva transformer and other oil-immersed units, which is the key to avoiding tank rupture and major equipment failure.
3. Aging Opening Performance
All finished pressure relief valves need to pass the static placement test. After being placed statically for at least 24 hours, the first opening pressure must still comply with standard values, ensuring stable performance after long-term standby for key equipment such as the 2500 kva transformer.
4. Sealing Performance
The valve has excellent vacuum and static pressure sealing performance. Under a vacuum residual pressure of ≤133Pa and a continuous test of 10 minutes, the permeability is no more than 1.33Pa.L/a, with no component deformation or damage. Under rated static pressure, the valve keeps completely leak-free within 2 hours, ensuring the tightness and insulation stability of the oil filled power transformer oil system.
Ⅴ. Company Introduction
JINSHANMEN TECHNOLOGY CO., LTD is a professional manufacturer and supplier of power transmission and distribution equipment. The company mainly produces oil immersed power transformers, dry-type power transformers, oil immersed three-dimensional coiled power transformers, dry-type three-dimensional coiled power transformers, mining explosion-proof dry-type transformers, mining explosion-proof mobile substations, amorphous alloy power transformers, on load capacity regulating power transformers, locomotive dry-type transformers, as well as prefabricated substations, modular substations, wind energy box type substations, high and low voltage switchgear and other transmission and distribution equipment. Adhering to strict national and international production standards, we provide high-quality, safe and reliable transformer equipment and supporting accessories for global power engineering projects.