Water hammer absorber

Water hammer absorber (also known as water hammer eliminator or water hammer absorber) is a key equipment that eliminates pipeline water hammer effect through air pressure buffering mechanism, widely used in building, industrial and municipal water supply systems. The following is the compilation of its core information:
1. Working principle and structure
Core mechanism: Through the dynamic movement of a sealed pressure chamber (pre filled with gas) and piston/rubber bladder components, the water hammer impact energy is converted into gas compression energy to achieve pressure balance.
Piston type: The piston movement inside the stainless steel cylinder adjusts the volume of the air pressure chamber, suitable for high-pressure stabilization systems (such as fire protection and power stations).
Rubber bladder type: The synthetic rubber inner liner expands and contracts to dissipate energy, suitable for space limited or fast response scenarios (such as small pump stations).
Diaphragm airbag type: Advanced rubber airbag+perforated tube structure, suitable for high-purity media (such as pharmaceuticals and chemicals).
2. Key technical parameters
Nominal pressure: PN16-25MPa, required to be ≥ pipeline working pressure (such as 2.5MPa commonly used in fire protection systems).
Diameter range: DN15-DN300, which needs to match the size of the pipeline (such as selecting DN100 model for DN100 pipeline).
Temperature adaptability: The valve body material is 304/316 stainless steel or cast copper, suitable for medium temperatures of 0-80 ℃.
3. Selection and installation points
Pressure regulation: The initial inflation pressure is 50% -70% of the pipeline pressure. For open systems, it is recommended to use 1-1.3kgf/cm2, which needs to be tested every six months.
Installation location:
Must be installed behind the gate valve of the water pump outlet pipe and at the corner of the pipe network;
When installed horizontally, the valve cover should face upwards, and when installed vertically, the valve stem should face outwards.
Complex scenario calculation: For long-distance water pipelines, the minimum volume of the buffer chamber needs to be calculated based on flow velocity, pressure, and other factors.
4. Typical application cases
High rise building fire protection system: After installing piston absorbers in a 30 story office building, the peak water hammer pressure decreased by 60% and the pipeline life was extended by three times.
Industrial pump station: The PetroChina refinery adopts 316 stainless steel piston type absorbers, which are double installed (below the pipeline and above the check valve) to effectively eliminate corrosive medium water hammer.