1. Background

Under normal circumstances, with the normal operation of the aircraft, the inner surface of the toilet sewage pipe will be contaminated and gradually become rough. After one year, the fouling will cause the sewage pipe to become thin. Once large foreign objects enter, it is very easy to happen Blocked. Under this circumstance, aircraft flights have to reduce the number of passengers carried in accordance with regulations. In severe cases, it will cause flight delays, cancellations, and parking, causing direct economic losses to airlines. Due to the presence of fouling in the sewage pipeline, the decomposition of the dirt under the action of bacteria will produce various odorous gases, which will affect the air quality in the cabin, affect the quality of service and the normal operation of the aircraft, and the problems of odor and blockage of the sewage pipeline have been It has become a headache for airlines and has attracted great attention. 

2. Reasons and solutions for the peculiar smell of aircraft vacuum toilets

The main reason for the peculiar smell of aircraft vacuum toilets is that the aircraft toilets, waterproof pads and other items will trap urinary alkali and other dirt, and the decomposition of dirt and bacteria will produce ammonia, hydrogen sulfide, nitrogen oxides and other odorous gases, or the toilet If the exhaust function fails, the toilet itself has an exhaust function to ensure that the peculiar smell of the toilet can be drawn out of the machine in time. If the normal air circulation is not allowed due to the malfunction, the gas will accumulate in the enclosed environment and produce peculiar smell.

Use the reactive deodorant BD501 to eliminate the peculiar smell of the toilet, and produce harmless and odorless gas to eliminate the peculiar smell. The sanitary agent BD500 can also be used for sterilization and disinfection of toilets and sewage pipes. Its chemical composition can kill most bacteria and inhibit The peculiar smell produced by bacteria decomposing dirt. 

3. Causes and solutions of fouling in aircraft sewage pipes

Human urine contains 70% of total dissolved solids (TDS), of which 40% of TDS is calcium and phosphate, urine is buffered by carbonate and carbonic acid systems, and the remaining part is urea. In the vacuum, the buffer system of urine will evaporate, the salt in it will become unstable and precipitate, and the precipitate will be deposited in the pipeline by means of ion adsorption. Over time, minerals and salt crystals in urine will become harder and more brittle, difficult to remove, and it is easy to form blockages with foreign objects in the pipeline.

Cleaning agents can be used to inhibit the accumulation of dirt in sewage pipes. According to the experience of many airlines, 1L of acid cleaning agent BD200 is added to the toilet every week. Its acidic components can chemically react with the dirt and control odors by reducing pollutants. Slow down the speed of fouling and prevent fouling and blockage of sewage pipelines.

In addition, regular deep cleaning of sewage pipelines (recommended), refer to AMM for deep cleaning of sewage pipelines. Positive and negative pressure can be used for cyclic cleaning (Aadilite cycle cleaning program). This method can be thorough Cleaning the stubborn dirt in the pipeline, especially the hard-to-clean parts of the elbow, has fundamentally solved this problem for airlines. 

4. Successful case sharing

Case 1: A B737-800 of a certain airline was blocked in the sewage pipeline during the flight and needed to be shut down for maintenance immediately, which would affect subsequent flights. After investigation, the maintenance personnel determined that there was a foreign object in the sewage pipeline blocking the pipeline, but the foreign object could not be taken out. Yadilite recommends China Southern Airlines to use the sewage pipeline recycling cleaning program and arrange for professional on-site guidance. Not only took out the perfume bottle that was stuck with the dirt and caused the blockage, but also removed the hard dirt in the pipeline, and completed the thorough dredging of the pipeline. See the following live photos:

Case 2: In an aviation base, a B737-800 took four hours to complete the cyclic cleaning of the aircraft's sewage pipeline, and the effect was remarkable. The use of the sewage pipeline circulating cleaning program is a comprehensive improvement of work efficiency and work quality. This is a cleaning method recommended in the manual. The circulating cleaning equipment is convenient to operate and can completely unblock the sewage pipeline and prevent blockage.

B737 aircraft numbered B20xx are undergoing cleaning

                       Comparison of pipeline before and after cycle cleaning

Case 3: Since 2019, Beijing Adilite has provided sewage pipe cleaning services for more than 20 subsidiary companies of an airline for the second consecutive year. After the sewage pipes have been cleaned, the aircraft has no clogging problems, which effectively reduces The grounding of aircraft, flight delays, and load shedding caused by the blockage of the vacuum toilet sewage pipeline have been unanimously recognized by airlines. And write B200T and sewage pipeline cleaning equipment into the work cards of B737/A320/A330/A380/B747/B777/B787 and other models, which has become the annual maintenance work for more than 600 airlines.

A321 numbered B-6xxx is undergoing cycle cleaning

B737-700 numbered B-5xxx is undergoing cycle cleaning

A320 numbered B-6xxx is undergoing cycle cleaning

B737-800 numbered B1*** is undergoing cyclic cleaning

                     Comparison of pipeline before and after cycle cleaning

5. Yadilite's overall solutions and advantages

Yadilite's cycle cleaning program is composed of BD200T sewage pipeline cleaning agent and sewage pipeline cleaning equipment, which is suitable for regular maintenance, off-site cleaning, cycle cleaning and other tasks. The product and equipment are currently the only domestic sewage pipeline cleaning agent and supporting equipment approved by the bureau. Compared with other cleaning methods, the Yadilite cycle cleaning program has the following advantages:

① The only sewage pipeline cleaning equipment approved by the Civil Aviation Administration of China, and obtained the national utility model invention patent.

② BD200T is included in the list of aerochemical products approved by the Civil Aviation Administration, and airlines can use it directly.

③ It can complete the cyclic cleaning of sewage pipelines without tedious steps, and can reduce costs and increase efficiency for airlines.

④ China Aviation Chemical Product Quality Assurance: The Civil Aviation Administration of China conducts re-inspection and update every two years to ensure product quality and safety.

⑤ Provide AOG technical support, and provide free equipment training and on-site guidance for customers. 

1. Products

BD200T sewage pipeline cleaning agent is a water-based cleaning agent. It uses an innovative combination of organic acid + surfactant + special additives to soften and strip the scale in the pipeline, and effectively remove the vacuum toilet system pipeline and sewage The hard scale on the box and parts can completely solve the blockage problem. The product has the 'Civil Aviation Chemical Product Design/Production Approval Letter' issued by the Civil Aviation Administration of China, and is included in the list of civil aviation chemical products. The quality is safe and reliable and can be used directly.

 Airworthiness certificate

The product is included in the list of aviation chemicals approved by the Civil Aviation Administration

The working mechanism of BD200T:

After BD200T sewage pipeline cleaner enters the pipeline, it will adhere to the various dirt in the pipeline in the form of foam, penetrate the dirt and cause cracks in a short time, and can easily fall off after the dirt softens. The current was washed away. 

2. Equipment

The sewage pipeline cleaning equipment model YDLT2015 is the only domestic sewage pipeline cleaning auxiliary equipment approved by the Civil Aviation Administration of China. It uses hoses to connect the sewage pipeline for circulating cleaning. Boeing's requirement for cyclic cleaning is positive pressure, while Airbus is negative pressure. This equipment can meet both positive and negative pressure cyclic cleaning at the same time. It is perfectly compatible with two working modes and is called the 'hemodialysis machine' of the aircraft.

Front, side, and back view of the device

6. Conclusion

Adilite provides a professional sewage pipeline cleaning solution for airlines. This solution not only improves work efficiency and reduces maintenance costs, but also completely solves the problem of peculiar smell in the cabin and blockage of sewage pipelines. This program has been widely used by more than 1,000 aircraft of more than ten domestic airlines. The convenience, safety compliance and actual economic cost of the cleaning process are better than similar products and processes, and it has reached the international leading level.