Under normal circumstances, for ball valves, globe valves, and gate valves, which has a higher likelihood of internal leakage or external leakage?
Thread Content
In general, for valves such as ball valves, globe valves, and gate valves, is the likelihood of internal leakage higher or that of external leakage? What is the difference? What is the probability of internal or external leakage within one year? It would be great if there were any data available. Thank you! !
It varies depending on different operating conditions; those that are toxic can be made leak-free.
All the descriptions below are based on an ideal model – a standard ball valve, gate valve, and globe valve with no influence from internal or external masses or factors, under identical environmental conditions – to compare their leakage potential: 1. Leakage potential of static seals (external leakage): The static seals of ball valves, gate valves, and globe valves all use gaskets combined with fastening bolts, and their sealing performance is equivalent. 2. In terms of the opening and closing mechanism: ball valves perform a partial rotation (90-degree rotation), while gate valves and globe valves involve multiple rotations (up and down movement of the valve stem); gate valves have the greatest stroke. From this perspective, the wear of the sealing packing is **least in gate valves – globe valves – ball valves; therefore, the packing in ball valves is relatively the most durable, while that in gate valves is the least durable. 3. Internal sealing structure: Ball valves and gate valves both feature dual valve seats for two-way sealing, while globe valves have a single valve seat for one-way sealing; from this perspective, the valve seat sealing of ball valves and gate valves is more reliable than that of globe valves. 4. Internal sealing mechanism: Ball valves utilize preloaded sealing; they achieve sealing through the pre-tension applied by design and assembly, as well as the force exerted by the medium ； Gate valves and globe valves feature forced sealing, which is achieved through the closing torque. From this perspective, the sealing life of gate valves and globe valves is superior to that of ball valves. Overall, considering actual operational conditions, the sealing service life of globe valves is the longest.
Bellows globe valves can achieve zero leakage
By \"no leakage,\" does it refer to internal or external leakage? Can it really be guaranteed 100% leak-free? There won’t be any failures, but there’s still a probability, right?
It is not disclosed to the outside, but the internal leakage of globe valves is comparable to that of gate valves, and greater than that of ball valves.
Why does the gate valve at the end of the pipeline leak internally? Ball valves can solve this problem – is it a quality issue with the gate valve?
Based on actual use, the probability of internal leakage is much higher than that of external leakage.
External leakage: During the warranty period, this is usually caused by inadequate wall thickness of the valve manufactured by the factory, casting defects, or issues with the valve selection. Internal leakage: In most cases, internal leakage occurs more frequently; this situation is more complex and is related to the frequency of use, the medium used, the pressure levels, as well as the manufacturing processes employed by the factory