The valve check valve has a significant effect on suppressing the water hammer phenomenon in the pipeline. Its core principle is to delay or block the violent transmission of pressure waves by accurately controlling the flow direction of the medium. When the pump body in the pipeline system suddenly stops or the valve is closed sharply, the high-speed flowing medium will form a reverse impact force due to inertia. This impact force is repeatedly reflected in the pipe to form a water hammer. The valve disc of the valve check valve can be quickly closed at the moment of reverse flow of the medium, like a "buffer gate" to prevent the medium from flowing back, cut off the continuous superposition of water hammer pressure waves from the source, and greatly reduce the pressure peak. For example, in the water supply system of high-rise buildings, after installing the valve check valve, the instantaneous pressure generated by the water hammer can be reduced by more than 40%, effectively preventing the pipeline from being damaged by severe vibration.
The structural design of the valve check valve further enhances the ability to suppress water hammer. Different types of valve check valves adopt differentiated designs for water hammer characteristics: the swing valve check valve has an optimized disc rotation angle, a smooth closing process and a short stroke, which can reduce the impact energy when the medium flows back; the slow-closing butterfly valve check valve controls the disc closing speed through a hydraulic device, so that the medium flow rate is gradually reduced to avoid sudden pressure changes caused by sudden cutoff. This "graded buffering" mechanism makes the pressure change in the pipeline more gentle, especially in long-distance water pipelines, which can reduce the impact range of water hammer to one-third of the original, reducing systemic risks.
In terms of improving system safety, the role of valve check valve is reflected in multiple key links. First, it can protect the core equipment in the pipeline from water hammer damage. The instantaneous high pressure generated by water hammer may cause the pump impeller to deform, the valve seal to rupture, and even cause the pipeline weld to crack. The valve check valve can reduce the failure rate of these equipment by more than 60% by suppressing water hammer. Secondly, for pipelines containing corrosive or high-temperature media, the violent vibration caused by water hammer may cause media leakage and lead to safety accidents. The stable closure of valve check valve can effectively prevent such leakage, providing important protection for the transportation of dangerous goods in industrial production.
The maintenance of system pressure stability by valve check valve indirectly extends the service life of pipelines and auxiliary equipment. The periodic pressure fluctuations caused by water hammer will loosen the bolts at the pipeline connection and wear the flange sealing surface, which may cause chronic leakage under long-term action. Valve check valve reduces the frequency and intensity of water hammer, so that the pipeline is always in a relatively stable pressure environment, and the loss rate of its connection can be reduced by more than 50%. In chemical production workshops, this stability can also ensure the operating accuracy of precision equipment such as reactors and heat exchangers, and avoid product quality deviations or production interruptions caused by pressure fluctuations.
The adaptability to different working conditions allows valve check valve to reliably play a safety guarantee role in complex systems. In high-temperature steam pipelines, metal valve check valves can withstand temperatures above 300°C and will not fail due to sudden temperature changes when water hammer occurs; in sewage treatment systems, corrosion-resistant valve check valves can keep the valve discs flexible in media containing impurities to ensure the timeliness of closing actions. This "all-condition adaptation" feature makes valve check valves a universal solution for suppressing water hammer and ensuring safety in various industrial pipelines.
The synergy between valve check valves and other protective equipment can build a more complete water hammer protection system. When used in conjunction with water hammer eliminators, pressure relief valves and other equipment, valve check valves are responsible for blocking the backflow of media, while other equipment further absorbs residual pressure waves to form "double protection". For example, in the circulating water system of a thermal power plant, this combination can reduce the rate of shutdown accidents caused by water hammer to less than 0.1%, which is much lower than 1.5% when valve check valves are not installed. This systematic protection not only improves the reliability of equipment operation, but also buys time for emergency response for operators and reduces the degree of harm caused by sudden accidents.
From the perspective of long-term economic operation, valve check valve can significantly reduce maintenance costs and accident losses by suppressing water hammer and improving system safety. According to industrial statistics, the annual maintenance costs caused by water hammer in pipeline systems equipped with qualified valve check valves can be reduced by more than 70%, and the equipment replacement cycle can be extended by 3-5 years. In high-risk industries such as oil and natural gas, a leakage accident caused by water hammer may cause huge losses, and the effective protection of valve check valve is equivalent to adding "safety insurance" to the system. The safety benefits it brings far exceed the purchase cost of the equipment itself, and it has become an indispensable safety barrier for the pipeline system.
