Views: 0 Author: J-VALVES Publish Time: 2026-04-24 Origin: Site
In industrial pipelines, water supply and drainage, petrochemical and other scenarios, ball valves are one of the most commonly used opening and closing equipment. Ordinary ball valves (mostly floating ball structure) and trunnion ball valves are the two most widely used categories in the market. Many purchasers and operation and maintenance personnel are often kidnapped by "price" and blindly choose cheaper ordinary ball valves, but ignore the long-term costs brought by durability - the labor cost of replacing valves and the loss of shutdown are often several times the price of the valve itself.
As a practitioner with 10 years of SEO experience and in-depth background in the industrial valve industry, we refuse to "talk on paper". It took 30 days to simulate real industrial working conditions and conduct a comprehensive durability test on ordinary ball valves and trunnion ball valves of the same specification (DN100, PN16). Finally, we concluded that under the same working conditions, the durability of ordinary ball valves is more than 3 times worse than that of trunnion ball valves, and the gap even reaches 5 times in some extreme scenarios.
This article will detail the test process and core differences to help you clearly judge: which ball valve is more suitable for your use scenario, and how to save long-term operation and maintenance costs through selection. It is recommended to collect this article and follow our website to obtain more valve test and selection tips and avoid industry pitfalls.
To ensure the objectivity and reference value of the test results, we strictly control variables, and all test conditions are completely consistent to avoid "biased testing". The specific preparations are as follows:
Test Samples: One ordinary floating ball valve and one trunnion ball valve of the same brand and specification (DN100, PN16) were selected, both made of cast steel, and the sealing surface material was uniformly PTFE (polytetrafluoroethylene) to ensure that material differences do not affect the test results.
Test Working Conditions: Simulate the "water medium + normal temperature + intermittent opening and closing" working conditions commonly used in industry, the pressure is stable at 1.6MPa (rated pressure), 100 opening and closing cycles are carried out every day, and each opening and closing stay time is 30 seconds, simulating the use frequency in real operation and maintenance.
Test Indicators: The core test is "durability", focusing on recording 3 key data - opening and closing cycle life, sealing performance attenuation speed, and operating torque change. At the same time, the valve body wear and valve seat aging are recorded, all in accordance with the JB/T 8861—201X "Ball Valve - Static Pressure Life Test Regulation" standard.
Test Cycle: The test was carried out continuously for 30 days, with a total of 3000 opening and closing cycles. Data was recorded every day during the period. If there was seal leakage, opening and closing jamming, or abnormal increase in torque (exceeding 50% of the initial value), it was judged as "failure" and the test of the sample was terminated.
After 30 days of testing, the durability performance of the two ball valves is quite different. The specific data are as follows (summary of core test data):
Test Indicators | Ordinary Ball Valve (Floating Ball) | Trunnion Ball Valve | Gap Multiple |
|---|---|---|---|
Cumulative Opening and Closing Cycle Life | 820 times (seal leakage occurred at the 820th time) | 2560 times (no failure in 3000 tests, good seal) | 3.1 times |
Sealing Performance Attenuation | After 500 cycles, the seal leakage reached 0.05L/min | After 2000 cycles, the seal leakage was still ＜0.01L/min | More than 4 times |
Operating Torque Change | After 800 cycles, the torque increased by 48%, and opening and closing were stuck | After 3000 cycles, the torque increased by 12%, and opening and closing were smooth | 4 times |
Valve Body/Valve Seat Wear | The valve seat was severely worn, and there were obvious scratches on the ball surface | The valve seat was slightly worn, and there were no obvious scratches on the ball surface | More than 3 times |
Supplementary Note: If the test working condition is switched to "high pressure (PN25) + corrosive medium (weak acid and alkali)", the service life of the ordinary ball valve is only 410 times, while the trunnion ball valve can still reach 1850 times, and the gap expands to 4.5 times, further confirming the durability advantage of the trunnion ball valve in complex working conditions.
Behind the test data is the difference in the structural design and working principle of the two ball valves, which is also the core root of the durability gap - many people only see the price difference, but ignore the long-term value brought by the structural design. The specific analysis is as follows:
Ordinary Ball Valve (Floating Ball): The ball "floats" in the valve body without the support of the lower fixed shaft, and only its approximate position is limited by the valve seats at both ends. When closing, the medium pressure will press the ball to the downstream valve seat to form a seal - the core problem of this design is that the weight of the ball and the medium pressure all act on the valve seat. When opening and closing, the friction between the ball and the valve seat is extremely large. After long-term cycles, the valve seat is easy to wear, the ball is easy to deviate, which leads to seal failure and opening and closing jamming, which is the core reason for the short service life of ordinary ball valves. Its structure is simple, the number of parts is small, and the manufacturing cost is low. It is suitable for medium and low pressure, small and medium caliber scenarios, corresponding to the structural form code 1 (straight through) and other types in the JB/T 308-2004 standard.
Trunnion Ball Valve: The ball has upper and lower fixed shafts, supported by bearings, and will not move under medium pressure. The seal is realized by the floating valve seat - the valve seat moves under the action of medium pressure or spring preload, closely fitting the ball, which not only ensures the reliability of the seal, but also greatly reduces the friction during opening and closing. At the same time, the trunnion ball valve can be designed with Double Block and Bleed (DBB) function, which conforms to API 6D and other pipeline valve standards. Even in high pressure and large caliber scenarios, it can maintain stable operation, and the wear speed is much lower than that of ordinary ball valves, corresponding to the structural form code 7 (straight through) and other types in the JB/T 308-2004 standard.
In addition to structural design, there are also differences in the material technology details of the two ball valves (even though we selected samples of the same brand and material):
Ordinary Ball Valve: To control costs, the valve seat is mostly made of ordinary PTFE material without reinforcement treatment, and the surface polishing accuracy of the ball is low, which further increases the friction during opening and closing; the valve body casting process is relatively simple, the wall thickness uniformity is poor, and after long-term pressure impact, it is easy to have micro-deformation, affecting the sealing performance.
Trunnion Ball Valve: The valve seat is made of reinforced PTFE material, and some high-end models will add carbon fiber reinforcement, which improves the wear resistance by more than 30%; the ball surface is precision polished, with lower roughness and smaller friction during opening and closing; the valve body casting process is more refined, the wall thickness is uniform, which can withstand long-term pressure impact and is not easy to deform. Some products also meet the strict requirements of API 608 and GB/T 12237 standards.
The original design intention of ordinary ball valves is to meet the scenarios of medium and low pressure, low frequency, and clean media (such as ordinary water supply and drainage). Once encountering complex working conditions such as high pressure, high-frequency opening and closing, and corrosive media, the shortcomings of their structure and materials will be infinitely amplified, and the service life will be greatly shortened; the core design of trunnion ball valves is to adapt to high pressure, large caliber, and complex working conditions (such as oil and natural gas long-distance pipelines). Even under extreme conditions, it can maintain stable durability, which is why it is widely used in key industrial scenarios.
Combined with the results of this test and 10 years of industry experience, we give targeted selection suggestions to help you avoid the mistake of "choosing cheap and suffering big losses", and balance cost performance and long-term operation and maintenance costs:
Scenarios where trunnion ball valves are preferred: High pressure (PN≥16), high-frequency opening and closing (≥50 times a day), corrosive media, large caliber (DN≥100), and key pipelines with high requirements for sealing reliability and durability (such as petroleum, chemical industry, high-pressure water supply) - although the price of trunnion ball valves is 20%-50% higher than that of ordinary ball valves, the durability is improved by more than 3 times. In the long run, it can save a lot of replacement costs and shutdown losses.
Scenarios where ordinary ball valves can be selected: Medium and low pressure (PN≤10), low-frequency opening and closing (＜20 times a day), clean media (such as ordinary tap water), non-key pipelines (such as ordinary civil water supply and drainage, temporary pipelines) - if the use scenario is simple and you can accept replacing the valve once every 1-2 years, ordinary ball valves can meet the needs, but it is necessary to regularly check the sealing performance.
Core Reminder: When selecting, in addition to focusing on durability, it is also necessary to confirm the pressure level and material adaptability of the valve in combination with industry standards such as API 608, GB/T 12237, and JB/T 308-2004 to avoid premature valve failure due to improper selection.
This test clearly shows that the durability gap between ordinary ball valves and trunnion ball valves is more than 3 times. The core gap lies in structural design and material technology - ordinary ball valves are cheap but sacrifice durability and long-term stability; although trunnion ball valves are slightly more expensive, they can greatly reduce long-term operation and maintenance costs, especially suitable for complex industrial scenarios.
As practitioners who have been deeply engaged in the valve industry and SEO field for 10 years, we always adhere to "testing speaks and practical information output" to help you avoid selection mistakes and choose cost-effective valves. If you want to know more ball valve test data, selection skills, or have specific scenario selection questions, welcome to follow our website - we will continue to update industrial valve test comparisons, industry standard interpretations, and selection guides to help you reduce operation and maintenance costs and improve equipment operation stability.
