Recently, the YD9-25 fuel-resistant polysulfide sealant of Beijing Yadilite Aviation Advanced Materials Corporation completed on-site application in an underground fuel storage tank sealing project. The product was used to seal the gaps between the tank shell and the reinforcing ribs. The complete application procedure was validated on site, fully demonstrating the excellent sealing performance of this fuel-resistant polysulfide sealant and its strong adaptability to on-site application.
The YD9-25 fuel-resistant polysulfide sealant is a two-component sealing product. The base compound is mainly made of liquid polysulfide rubber, with additives such as reinforcing agents, tackifiers and stabilizers; the curing agent component uses manganese dioxide as its main raw material, compounded with accelerators, anti-corrosion agents and plasticizers. The product features excellent fuel resistance, high- and low-temperature resistance and corrosion resistance, with a density grade of 1.40-1.50 g/cm³. Its long-term service temperature range is -55 °C to 121 °C, and it can withstand short-term exposure to temperatures up to 180 °C. The main product grades include A-2, A-4, B-1/2, B-2 and B-4, and custom matching can be provided based on on-site application conditions. The product complies with Q/YDLT 0030-2024 and AMS-S-8802, and is benchmarked against comparable products such as PR1422, PS890 (PPG) and HM111. Packaging options include 1 kg/set and 5 kg/set pails and 6 oz cartridges, and custom packaging specifications can also be provided upon customer request.
The subject of this application was an underground fuel storage tank. Through gaps exist between the tank shell and the reinforcing ribs, and filling and sealing work is required on the outside of these gaps. The sealant is applied to both sides of the reinforcing ribs. As the gaps are relatively small, proper external seam sealing is required to prevent leakage of the medium.
The complete on-site application process consists of four key steps: applying the primer, mixing the sealant, filling the sealant into cartridges, and applying the sealant with finishing.
The first step is applying the primer, for which a soft-bristle brush is used. First, the abraded substrate is cleaned with a suitable solvent; then the brush is dipped into the primer and applied evenly to the area to be sealed. This operation has clear time-control requirements: the primer must be applied 15 minutes before the sealing work; after the primer is applied, the subsequent sealant application must be completed within 8 hours; if sealant application is not carried out within 8 hours, the primer must be reapplied. For low-surface-energy substrates, the application area must be abraded with a scouring pad.
The second step is mixing the sealant, carried out with an electric mixer and the sealant's packaging pail. The matching curing agent is added to the base compound pail, and mixing can be done directly in the original 5 L pail with the power tool for 10 minutes; local areas on the pail wall require manual mixing. During the process, the ambient temperature and humidity should be controlled and the mixing quantity estimated in advance, so as to prevent waste caused by premature curing of the sealant. The speed and duration of mechanical mixing should be controlled to prevent temperature rise in the compound from accelerating curing. Material on the pail wall and bottom that is not fully mixed should be stirred manually until completely uniform.
The third step is filling the sealant into cartridges, using 300 mL cartridges and a spatula. The mixed sealant is manually loaded into the cartridge; the cartridge is then shaken thoroughly to expel internal air, after which a vent guide is inserted and the tail plug installed. The cartridge should not be overfilled, so as to prevent the sealant from overflowing during application; internal air bubbles should be expelled as completely as possible to ensure sealing quality. Filling a single cartridge takes about 2-3 minutes, and manpower can be allocated according to the on-site staffing.
The fourth step is applying the sealant and finishing. The tools include a sealant gun and finishing tools. The sealant is applied evenly to the gaps to be sealed. After application, a scraper is used to repair and finish defective areas, and the sealant is then left to cure as required by the specification before subsequent work proceeds. Local defects should be repaired and finished accordingly.
Judging from the results of this on-site application, the YD9-25 fuel-resistant polysulfide sealant fully meets the requirements for external sealing of the reinforcing rib seams of underground fuel storage tanks. The project experience suggests that before work starts, the on-site conditions should be comprehensively assessed, and the curing agent dosage and mixing process conditions adjusted according to the on-site temperature and humidity. The entire operation follows a mode of manual cartridge filling, air expulsion, sealant application and finishing, which is simple and convenient; in this project, the overall application period for four 100-tonne fuel storage tanks was only one day.
Backed by a professional R&D team, the company has full mastery of the core technology of sealing materials and is able to carry out custom development and formulation adjustment of multiple types of sealants according to different working conditions and application scenarios, fully meeting the differentiated and complex sealing requirements of various projects.
This project validated the company's complete technical service system, delivering a full closed-loop service covering product supply, on-site technical support, hands-on training and whole-process quality control. Upon receiving the project requirement, the company achieved rapid product dispatch, delivering the products to the site within 24 hours, while professional technical personnel were sent to the site at the same time to conduct construction process briefings and hands-on training, track and control every step of the on-site process, and strictly manage key application points and process parameters. With rigorous technical capability and standardized control procedures, the company ensured the quality of the sealing work, providing a reliable and complete integrated solution for fuel storage tank sealing projects.