Loose flange (slip-on flange) connection is a highly adaptable pipeline connection method for UV disinfectors in water treatment scenarios such as secondary water supply and sewage treatment. Its core advantages are highly matched with the installation, operation, maintenance and on-site construction characteristics of UV disinfectors, solving the pain points of rigid connection such as difficult centering, inconvenient disassembly and easy stress damage. The specific advantages are as follows:
1. High installation flexibility, easy to compensate for pipeline deviations
The loose sleeve structural design of the loose flange allows the flange to slide slightly on the pipeline end, which can fine-tune the axial, radial and angular positions within a certain range. It can effectively compensate for the coaxiality deviation, slight angle offset and axial gap unevenness caused by civil engineering errors, pre-laying of on-site pipelines and equipment hoisting errors. It avoids the need for secondary cutting, welding or rework of pipelines due to inaccurate alignment, greatly reduces the difficulty of on-site installation, shortens the construction period, and prevents the equipment interface and quartz sleeve from being damaged by excessive stress due to rigid hard connection.
2. Convenient disassembly and assembly, reducing the difficulty of daily maintenance of UV disinfectors
The core maintenance of UV disinfectors focuses on quartz sleeve cleaning, lamp tube replacement and internal overhaul, which requires regular disassembly of the inlet and outlet pipeline connections. Loose flange connection adopts a full-bolt fixed structure, which can separate the pipeline and the disinfector only by loosening the flange bolts without cutting or welding the pipeline. Compared with fixed welding flanges and welded pipe connections, it saves more than 80% of the disassembly and assembly time, and is especially suitable for scenarios with high maintenance frequency such as sewage treatment (easy scaling of sleeves) and small and medium-sized UV disinfectors without automatic cleaning functions. It also adapts to the maintenance operation in compact spaces such as pump rooms with limited operating space.
3. Adapt to the butt joint of different material pipelines, avoiding thermal stress damage
In water treatment projects, the body pipeline of UV disinfectors is mostly 304 stainless steel, while the on-site matching pipelines may be carbon steel, UPVC, cast iron and other materials. Different materials have large differences in thermal expansion coefficients, and temperature changes will cause pipeline thermal expansion and contraction to generate internal stress. Loose flanges can buffer the relative displacement of pipelines of different materials through their loose sliding structure, avoid stress concentration at the equipment interface, and prevent seal failure and pipeline cracking caused by thermal stress. At the same time, only by replacing the matching gaskets (nitrile rubber, fluororubber, etc.), loose flanges can meet the sealing requirements of butt joint of different material pipelines, with strong compatibility.
4. Safe and fireproof, suitable for on-site construction without hot work conditions
Loose flange connection is a cold connection process that does not require welding, cutting and other hot work operations during on-site installation and disassembly. It is fully compliant with the safety construction specifications of scenarios where hot work is prohibited, such as high-rise building pump rooms, underground enclosed spaces, flammable and explosive chemical park sewage treatment stations, and water supply facilities near fire protection zones. It avoids fire risks, pipeline deformation and paint falling off caused by on-site hot work, and also eliminates the need for complex approval procedures for hot work, improving construction efficiency.
5. Stable sealing under medium and high pressure, suitable for large-caliber UV disinfector scenarios
For large-caliber UV disinfectors (DN80 and above) and medium and high pressure pipeline systems (working pressure ≥0.6MPa) such as municipal sewage main pipes and high-rise secondary water supply pressurization systems, loose flanges can be equipped with high-pressure sealing gaskets (metal spiral wound gaskets, high-pressure fluororubber gaskets) to ensure reliable sealing performance and meet the pressure resistance requirements of water treatment pipelines. At the same time, the centering difficulty of loose flanges for large-caliber pipelines is much lower than that of fixed flanges, which can avoid the problem of poor sealing caused by concentricity errors of large-caliber pipeline rigid connection, and effectively disperse the pipeline pressure impact on the disinfector body, protecting the internal precision components such as lamp tubes and electronic ballasts.
6. Facilitate later project transformation, relocation and capacity expansion with low reconstruction cost
In the later stage of water treatment projects, there may be needs such as UV disinfector relocation, equipment upgrade and replacement, and pipeline capacity expansion. Loose flange connection can realize quick disassembly and re-butt joint of pipelines and equipment, without damaging the original pipeline structure and equipment interfaces. It can be directly reconnected with new pipelines or equipment only by adjusting the flange position, which reduces the reconstruction cost by more than 60% compared with the welded connection that needs to cut and re-weld the pipeline, and shortens the project shutdown time, minimizing the impact on normal water supply and drainage operations.
7. Low requirement for on-site construction technology, reducing construction quality risks
The installation of loose flanges does not require high-level welding technology and pipeline centering precision. Ordinary construction personnel can complete the standard installation only by mastering the basic bolt tightening and level calibration skills. The uniform diagonal tightening principle of flange bolts is easy to operate, which can effectively avoid the problems of seal failure and water leakage caused by uneven stress on gaskets due to improper construction. Compared with fixed welding flanges that require professional welders to ensure welding quality, loose flanges reduce the dependence on on-site construction technology and lower the risk of installation quality defects.
8. Easy to replace accessories, strong interchangeability of spare parts
Loose flanges adopt national standard size design, and the matching bolts, gaskets and other accessories are universal standard parts, which are easy to purchase and replace on the market. In case of damage to flange gaskets or bolts during use, they can be quickly replaced with standard spare parts without customizing non-standard accessories according to the equipment model, which reduces the inventory pressure of spare parts and the maintenance waiting time of UV disinfectors.
Key Supplement: The sealing performance is controllable, and the disadvantage of poor initial sealing is easy to make up for
The initial sealing of loose flanges is slightly lower than that of fixed welding flanges, but this disadvantage can be completely made up for by matching high-quality gaskets (food-grade nitrile rubber for drinking water, fluororubber for corrosive water quality) and following the uniform diagonal tightening operation specification. For the water treatment industry with low requirements for ultra-high pressure, the sealing performance of loose flanges can fully meet the national standard requirements of secondary water supply and sewage treatment.
