Statistics show that about 20% of valves in industrial installations have the problem of leakage. The direct economic loss caused by them accounts for about 50% of the total loss, and the valve leakage can cause serious pollution to the environment. The principle of temperature measurement using Fluke can Valve leak detection, to avoid production accidents.
What are the usual valve failures?
Valve leakage is divided into two types, namely, external leakage and internal leakage.
1 leakage common in the valve body, stem, stuffing box and valve body connection parts.
a) The body is usually cast, easy to form casting defects such as trachoma, the body of the trachoma will lead to media leakage, the leakage is generally manifested as leakage, flow rate smaller.
b) valve stem due to improper design and material selection will cause the stem in a certain position is stuck, so that the valve can not be closed or closed lax, resulting in media leakage. Such spills tend to be more fluid and pose a serious risk to the production plant and the surrounding environment.
c) packing valve by the stuffing box, packing, packing pad and packing compaction and other components. The stuffing box is placed on the valve body or bonnet and serves to contain the packing. The packing pad is placed at the bottom of the packing box to play the role of supporting packing. Filler soft seal packing and molding two. The medium leaks at the seal packing because the packing gland is loose, the seal packing is not tight, the type or quality of packing does not meet the requirements, the packing is aged or worn by the valve stem.
d) The seal at the connection of the body means the seal between the body and the bonnet. Under normal circumstances, the flange connection seal, when the nominal diameter of the valve is smaller when the screw connection seal. Gasket of the type, material or size does not meet the requirements of the flange sealing surface processing poor quality, improper fastening bolts, due to unreasonable pipeline configuration in the connection generated excessive load and other reasons, can cause the valve body connection site leakage.
2 valve closed lax leakage as internal leakage, often occurs in the seat sealing surface.
a) valve design and manufacturing process there is a problem, resulting in lax valve sealing and lead to media leakage, mostly leakage or small discharge continuous discharge.
b) Valve plate or sealing surface deformation caused by lax sealing, resulting in media leakage, generally into a small leakage or leakage of continuous discharge.
c) In the process of manufacture, transportation, inspection, installation and use of the valve, the sealing surface of the valve is damaged so that the seal is not tight and the valve leaks. This leakage is also manifested as leakage of small flow.
d) The medium contains solid impurities caused by the valve is not closed, resulting in media leakage. This leak may be a small flow of leakage may also flow larger.
Why can the infrared camera detect valve leakage?
Leakage detection valve using the infrared thermometer temperature measurement principle, as long as the pipeline medium and the ambient temperature there is a certain difference, through the far infrared camera infrared detection and analysis of the valve to confirm the internal leakage of the valve and the leakage Degree, and the valve leakage. However, due to the valve, pipe insulation, metal, to analyze the extent and causes of internal leakage has caused some difficulties. If the valve, the pipe is not insulated, the valve is easy to determine the internal leakage. In particular, many of the pipe valve to the Explorer difficult to determine which valve leaks, the use of a far infrared camera can quickly detect the leakage of the valve and replaced, to avoid the blindness of the work, saving costs. Typical customers
Petrochemical industry: Quzhou Juhua, Dushanzi Petrochemical, Yangzi Petrochemical - BASF and so on
Pharmaceutical industry: Johnson & Johnson and other pharmaceuticals
Metallurgical Industry: Baosteel, Masteel, Tianjin Tiantie and so on
The unique application of thermal imaging 1 valve leakage, leakage outside the valve is generally difficult to detect, and its great harm. The use of infrared thermography temperature principle can quickly and intuitively detect the valve leakage and external leakage, reduce maintenance workload and improve efficiency.
2 If the valve is adjusted to a corrosive or dangerous medium, there is a significant risk that personnel will detect it near the valve. Or, if the valve is high or inaccessible to personnel, it is very difficult to detect it routinely. The Fluke thermal imager can be detected at a distance from the valve on the ground, providing a high level of safety.
3 Fluke's patented IR-Fusion technology, in addition to capturing infrared images, captures a single digital photograph and blends it together to help identify and locate problems so they can be correctly repaired in the first place.
4 The Fluke infrared camera is equipped with powerful software for storing and analyzing thermal images and generating professional reports. Through the software, you can adjust the emissivity, reflection temperature compensation and color palette and other key parameters in the thermal image to improve the safety and convenience of inspection.
What problems may be encountered on site?
1 If the valve insulation thicker, the internal temperature difference is not easily transmitted to the outer wall surface, it is more difficult to measure leakage.
2 part of the valve housing is bright iron or stainless steel, its low emissivity and high reflectivity, easy to heat near the high temperature radiation source into the thermal imaging camera, causing serious interference in the filming of such valves can leak prone parts Paint with paint (any color) to increase the emissivity of the area.
How to shoot a clear thermal image?
1 For occasions requiring a small temperature difference, try to choose a Fluke thermal imaging camera with high thermal sensitivity.
2 shooting should pay attention to try to avoid measuring direct sunlight, the filming in the shadow of the valve is not easy to sunshine, the effect is better.
3 When shooting observe whether there is any other heat around, especially for the surface of the valve is relatively bright, the shell is easier to reflect around the heat source, causing the test interference, so when shooting around the heat, please change the shooting angle.
4 Use automatic mode to measure the temperature range of the tank first; then set the level and span manually to minimize the temperature range and include the previously measured temperature range (the minimum temperature ranges for the various instruments).
Chongqing Yuntu Automobile Trading Co., Ltd. , https://www.yuntuauto.com