Overview of XXDF-1 type water-based bottom valve
Each water pump should be equipped with a bottom valve, which is usually installed below the water surface, while the water-based bottom valve is installed above the water surface. It is an upgraded product of the old-fashioned bottom valve, an ideal water diversion equipment, and can also replace vacuum pumps and vacuum pumping devices.  
The XXDF-1 water-based bottom valve was designed by a professional design institute of the Ministry of Railways. It passed ministerial level appraisal in 1985 and won the Ministry of Railways Science and Technology Progress Award in 1986. It has been included in the ninth volume of the "Water Supply and Drainage Design Manual". In 1990, the second issue of the "Energy Communication" magazine reported on this bottom valve under the title "Efficient and Energy saving Water Bottom Valve". In 1994, it was awarded the title of Excellent Energy saving Product by the National Economic Commission, Planning Commission, and Science and Technology Commission during the National Double 500 Campaign. The bottom valve is designed reasonably, manufactured with advanced technology, and easy to install, use, and maintain. And it has the advantages of low friction resistance, long service life, energy saving, etc., and is widely used as a supporting facility for water pumps in industries such as petrochemicals, chemicals, textiles, printing and dyeing, metallurgy, mining, and irrigation.

Features
1. It can replace underwater bottom valves, be installed at the 90 ° bend between the horizontal pipe and the inlet pipe above the water surface, and can also replace elbows. Its unique sealing performance achieves no leakage and is equipped with damping devices, which have a certain mitigating effect on water hammer hazards.
2. The energy-saving effect is significant, which can save about 5-7% energy during normal operation and use (based on a thousand tons/meter of electricity consumption). After one to two years of use, the saved electricity cost can be recovered from the investment cost of purchasing this valve. Its energy-saving effect is beyond the reach of general bottom valves.
3. The bottom valve has a long service life and easy maintenance. Its service life is over five years, greatly reducing production costs. Moreover, there are generally no major malfunctions during its service life. Even if there are malfunctions, they can be easily and quickly handled. It fully demonstrates its superiority.
4. The self-priming performance is reliable. As is well known, the sealing performance of old-fashioned bottom valves is poor, and there is often a problem of not being able to discharge water after the pump stops. However, water-based bottom valves have a unique sealing effect, which can achieve no leakage and ensure the smooth operation of the next pump start. Therefore, in the design process, it is not necessary to consider the use of a large investment underwater pump room water supply engineering scheme due to the pump not being able to discharge water.
5. All connecting flanges of this product comply with GB regulations and have good universal performance.
Instructions for Use
1. Specifications: DN50、DN65、DN80、DN100、DN125、DN150、DN200、DN250、DN300、DN400、DN500、DN600、DN700、DN800 Waiting for specifications.
2. Nominal pressure: 0.6MPa
3. Installation requirements: Install at the bend between the vertical and horizontal pipes of the water pump suction pipe, ensuring its vertical position during installation.
4. Start: Immediately start the horizontal pipe after filling it with water for the first time, causing a semi vacuum state inside the suction pipe, and suck water into the vertical pipe to complete the pumping process. When the suction stroke is too large, it is necessary to repeat the water filling process several times before stopping the pump. There is no need to fill the pump with water before starting it.
5. Maintenance: In general, maintenance is not necessary for use. When maintenance is required, simply open the valve cover on the water type bottom valve and replace the rubber gasket. After maintenance, continue to start the pump according to the first start method.
6. If used in fluids with high acid and alkali concentrations, please choose stainless steel water-based bottom valves. At the same time, our factory can produce all plastic water-based bottom valves or 316L (molybdenum titanium) water-based bottom valves according to user requirements.

4、 Outline dimension table for installation of water-based bottom valve