The union type pressure gauge is primarily designed for measuring pulsating pressures, such as those used in fracturing and cementing equipment in oil production. It can also be used to measure static pressures. The internal damping mechanism of the instrument effectively dampens pressure pulsations across the entire measurement range without the need for adjustment during use. Therefore, the instrument not only provides stable and clear readings when measuring severe pulsating pressures but also withstands instantaneous pressure impacts (such as sudden depressurization). The instrument has excellent shock resistance; the filling liquid inside the gauge head allows it to operate normally in environments with strong vibrations, preventing the pointer from swinging excessively due to vibration. The instrument has an anti-clogging feature, preventing the measured medium from entering the internal parts of the instrument, making it suitable for use in environments with high viscosity, high particle size, and easy solidification, such as mud and cement. The instrument has reliable sealing and anti-corrosion measures, allowing it to work in harsh environments.