Ball Valve Internal Leakage Causes & Professional Solutions | Industrial Valve Guide

Internal leakage is a prevalent and easily overlooked fault of ball valves widely used in petrochemical processing, natural gas transmission, power generation and industrial pipeline systems. Different from visible external leakage, internal medium seepage leaves no obvious spillage on the valve surface, making it hard to detect during daily field inspections. However, persistent tiny leakage will trigger unstable production processes, frequent pressure fluctuations and medium waste. For valves operating under high-pressure environments, long-term internal leakage will also accumulate hidden safety risks, threatening the stable operation of the entire pipeline system. Field operation data verifies that ball valve internal leakage mainly stems from four practical working condition problems. The first is aging and permanent deformation of valve seats. Soft sealing materials including PTFE, RTFE and NBR rubber will suffer creep deformation, hardening and structural collapse after long-term high-pressure compression, repeated temperature changes and frequent valve switching. Once the sealing surface loses flatness and integrity, tiny gaps will form. Even if the valve is fully closed, it cannot achieve standard zero-leakage effect. Second, solid particle erosion and sealing surface scratch damage. Pipeline impurities such as welding slag, rust scale, sand grains and suspended solid particles flow with the medium at high speed. These hard impurities continuously impact and scrape the ball core and valve seat sealing surface during operation. Even micro scratches can destroy the complete sealing line between matching parts, resulting in irreversible continuous internal seepage. Third, insufficient actuator torque leads to incomplete closing stroke. After years of continuous operation, gearbox wear, insufficient lubricating grease and increased valve stem friction will reduce the actual output torque of electric and pneumatic actuators. The ball core fails to reach the fully closed limit position, forming a pseudo-closed state and causing sealing failure. Fourth, medium scaling and sediment deposition. Crude oil, crystallizable chemical media and industrial sewage are prone to form hard scale deposits on the surface of the ball core. These accumulated sediments separate the ball core from the valve seat, breaking the close fit of the sealing pair and causing persistent internal leakage. For on-site maintenance and renovation, enterprises can adopt targeted improvement measures. Strengthen pipeline filtration before system commissioning to reduce impurity content; replace aging soft valve seats regularly according to operating hours; calibrate actuator torque and limit stroke every quarter; and maintain regular valve stem lubrication. For harsh working conditions with high temperature and solid particle impurities, upgrading to metal-seated ball valves is the most effective way to completely solve long-term internal leakage problems.