Features:

1. Dual function, to reduce negative pressure, corrosion-resistant material,brightly colored appearance, good visibility, strong shock resistance, high durability and easy to install.
2. Usage: used in pipeline system, to prevent water impact.
3. Installed in relatively high point, to expel air of pipeline system whenstart up system, while, to introduce air to prevent vacuum when close system.
4. Installed in the first system.