How to Choose the Right Gas Safety Relief Valve? A Full-Scenario Selection Guide from Automatic Pressure Relief to Corrosion Resistance

How to Choose the Right Gas Safety Relief Valve? A Full-Scenario Selection Guide from Automatic Pressure Relief to Corrosion Resistance

In scenarios such as industrial production, household gas use, and chemical storage, Gas automatic relief valves, gas relief valves, and safety relief valves are core components ensuring the safe operation of gas systems. Their core function is to automatically open and relieve pressure when the pressure in the system exceeds the set value, preventing pipelines, storage tanks, or equipment from exploding or being damaged due to overpressure. The performance requirements for these valves vary greatly across different scenarios—industrial pipelines need to withstand high pressure and frequent start-stops, household gas appliances require a balance of convenience and safety, and LPG storage tanks need to resist corrosive media. Improper selection may lead to safety hazards. Therefore, choosing the right gas safety relief valve requires comprehensive consideration of factors such as the pressure range, medium characteristics, and space size of the usage scenario. Next, we will analyze the design key points and selection logic of various gas safety relief valves based on the core needs of different scenarios, helping users avoid selection mistakes.

What Are the Core Design Requirements for Gas Automatic Relief Valves Used in Industrial Gas Pipelines?

Industrial gas pipelines (such as natural gas transmission pipelines and blast furnace gas pipelines) have high transmission pressure, large flow rates, and require 24/7 continuous operation. The corresponding gas automatic relief valves need to meet three core design requirements: "high-pressure resistance", "fast response", and "stable operation". First, in terms of high-pressure resistance, the valve body must be made of high-strength alloy materials (such as chrome-molybdenum steel), and the wall thickness of the valve body must be determined based on the maximum working pressure of the pipeline to ensure no deformation or leakage under 1.2 times the design pressure. At the same time, the valve sealing surface must be coated with a hard alloy to improve wear resistance and sealing performance, avoiding pressure loss due to seal failure after long-term use. Second, fast response is crucial—when the pipeline pressure exceeds the set value (usually 1.1 times the working pressure), the valve must open to relieve pressure within 0.5 seconds, and the pressure relief diameter must match the pipeline flow rate to ensure the pressure is reduced to a safe range in a short time, preventing risks caused by continuous pressure rise. In addition, considering that industrial pipelines need to operate continuously for a long time, the valve must also have a "self-cleaning function". A built-in filter structure prevents impurities in the gas from jamming the valve core, ensuring the valve can still operate stably after frequent start-stops. This is also a core difference between gas automatic relief valves for industrial scenarios and those for other scenarios.

How Do Corrosion-Resistant Gas Relief Valves for LPG Storage Tanks Resist Corrosion and Extend Service Life?

During the storage of LPG (liquefied petroleum gas), sulfides and moisture contained in the medium itself can corrode the valve. If the gas relief valve has insufficient corrosion resistance, it may cause valve core rust and seal failure, and in severe cases, even fail to relieve pressure normally. Therefore, corrosion-resistant gas relief valves for LPG storage tanks need to improve corrosion resistance from three aspects: "material selection", "surface treatment", and "structural design". In terms of materials, the valve body is mostly made of 316L stainless steel, which contains molybdenum and has corrosion resistance to sulfides and organic acids more than 50% higher than ordinary stainless steel, effectively resisting corrosion from LPG media. The valve internals (such as the valve core and spring) are made of Hastelloy to further enhance corrosion resistance. In terms of surface treatment, the outer part of the valve body needs to undergo sandblasting for rust removal and fluorocarbon paint spraying to form a dense anti-corrosion coating, preventing external rust of the valve body caused by the humid environment around the storage tank. In terms of structural design, the valve must adopt an "inverted seal" structure. When the valve is closed, the contact area between the sealing surface and the medium is minimized to reduce long-term adhesion of corrosive media. At the same time, the valve must have a reserved sewage outlet to regularly discharge condensed water and impurities accumulated in the valve cavity, avoiding intensified local corrosion. Through these designs, the service life of such gas relief valves can be extended from 3 years of ordinary valves to more than 8 years, significantly reducing maintenance costs.

How Do Safety Relief Valves for Household Gas Appliances Ensure Daily Use Through Safety Protection Mechanisms?

Household gas appliances (such as gas stoves and gas water heaters) are used in scattered scenarios, and users have varying operating levels. The corresponding safety relief valves need to ensure safe use for non-professional users through multiple protection mechanisms. First, such valves must have an "overpressure automatic cut-off" function—when the gas pipeline pressure suddenly rises (such as pressure exceeding 3kPa due to upstream pressure regulator failure), the valve will automatically close the gas path and open the pressure relief port to release a small amount of gas, preventing overpressure gas from entering the gas appliance and causing backfire or deflagration. Second, considering the possibility of "valve misoperation" in household scenarios, the valve must be designed with a "manual reset" function. After pressure relief, the user must manually rotate the reset knob to resume gas supply, preventing the valve from automatically resetting and continuing to use without troubleshooting hidden dangers. In addition, the valve must also have an auxiliary "leak detection" function. Some products are equipped with a pressure observation window on the valve body, allowing users to judge whether the valve has internal leakage by observing the pointer or color change in the window, and promptly detect minor leakage problems. These protection mechanisms are progressive, not only avoiding overpressure risks but also reducing safety hazards caused by user operation errors, fully adapting to the safety needs of household scenarios.

How Is Pressure Control Precision Achieved in High-Pressure Gas Automatic Relief Valves for Chemical Plants?

Gas systems in chemical plants (such as chlorine and ammonia storage systems) have high working pressure (usually exceeding 10MPa) and highly dangerous media. The corresponding high-pressure gas automatic relief valves need to achieve a pressure control precision of ±0.2% to ensure the system pressure is stably maintained within a safe range. This precision is mainly achieved through "high-precision springs", "multi-stage pressure regulation structures", and "dynamic sealing designs". First, the valve uses imported precision alloy springs with a spring stiffness error controlled within ±1%, ensuring minimal spring force change at different temperatures (-20℃ to 80℃) and avoiding set pressure drift caused by temperature fluctuations. Second, the valve body adopts a multi-stage pressure regulation structure internally. Through the cooperation of the main valve core and the pilot valve core, pressure control is divided into two steps: "rough adjustment" and "fine adjustment". The pilot valve core first senses pressure changes and controls the opening degree of the main valve core through small displacements, realizing precise pressure adjustment and avoiding pressure fluctuations caused by excessive displacement of a single-stage valve core. Finally, dynamic sealing design is crucial. The valve uses "metal bellows sealing" instead of traditional packing sealing, which can adapt to the high-frequency small-amplitude movement of the valve core, ensure no medium leakage under high pressure, and avoid seal failure caused by packing wear. Through these designs, high-pressure gas automatic relief valves can long-term control the system pressure within ±0.2% of the set value, meeting the strict pressure precision requirements of chemical plants.

How to Balance Space Adaptation and Safety Performance in Compact Safety Relief Valves for Small Gas Cylinders?

Small gas cylinders (such as small hydrogen cylinders for laboratories and portable acetylene cylinders) have small volumes (usually less than 10L) and are frequently moved. The corresponding compact safety relief valves need to balance "small volume" and "full functionality", adapting to the narrow installation space of the cylinder without sacrificing safety performance. In terms of space adaptation, the valve adopts a "vertical compact structure" with a valve body height controlled within 50mm. The inlet and outlet interfaces use threaded connections (such as G1/2 threads), which can be directly installed on the valve interface at the top of the cylinder without additional horizontal space occupation. At the same time, the valve operating handle is designed to be foldable, which can be folded to fit the valve body when not in use, avoiding handle damage caused by accidental collision during transportation. In terms of safety performance, although the compact safety relief valve is small in size, its core functions are not reduced—it still has overpressure automatic pressure relief, manual closing, and pressure locking functions, and the pressure relief port direction can be adjusted 360°, preventing gas from directly spraying onto operators or surrounding equipment during pressure relief. In addition, the valve must pass vibration tests to ensure that the valve core does not shift due to vibration during cylinder transportation (such as bumping and tilting), leading to pressure loss. This "small but comprehensive" design allows the compact safety relief valve to perfectly adapt to the usage scenario of small gas cylinders while ensuring safety during transportation and use.