ATOS relief valve AGAM-10/210/V in stock
$253.19
The noise emitted by Italian ATO pilot-operated relief valves sometimes includes high-frequency mechanical vibrations, generally referred to as self-excited vibration. This sound is caused by high-frequency vibrations in the main valve and pilot valve. Its occurrence rate is related to factors such as the configuration of the return oil pipeline, flow rate, pressure, and oil temperature (viscosity). Generally, smaller pipeline diameters, lower flow rates, higher pressures, and lower oil viscosity result in a higher rate of self-excited vibration.
Brand
ATOS/Italian Atos
ATOS Vane Pumps, ATOS Cylinders, ATOS Relief Valves, ATOS Proportional Valves, ATOS Stack Valves, ATOS Solenoid Valves
ATOS relief valves are hydraulic pressure control valves, primarily used in hydraulic equipment for constant pressure relief, pressure stabilization, system unloading, and safety protection. During assembly or use, damage to O-rings or combination seals, or loosening of mounting screws or pipe joints, can cause undue external leakage.
If the cone valve or main valve core is excessively worn, or if there is poor contact at the sealing surface, excessive internal leakage can occur, even affecting normal operation.
In hydraulic systems, pumps and valves are generally considered to be the most prone to noise generation, with relief valves and solenoid directional valves being the main types of valves. Many factors contribute to noise generation. Relief valve noise can be categorized into flow velocity noise and mechanical noise. Flow velocity noise is mainly caused by oil vibration, cavitation, and hydraulic shock. Mechanical noise is mainly caused by the impact and friction of parts within the valve.
(1) Noise caused by uneven pressure
The pilot valve section of a pilot-operated relief valve is a vibration-prone part, as shown in Figure 3. During high-pressure relief, the axial opening of the pilot valve is very small, only 0.003~0.006 cm. The flow area is small, and the flow velocity is very high, reaching 200 m/s, easily causing uneven pressure distribution, resulting in an imbalance of radial force in the cone valve and vibration. Additionally, the ellipticity generated during the machining of the cone valve and cone valve seat, dirt adhering to the pilot valve port, and deformation of the pressure regulating spring can also cause cone valve vibration. Therefore, the pilot valve is generally considered the source of noise.
The presence of elastic elements (springs) and moving mass (cone valve) creates conditions for oscillation, and the front cavity of the pilot valve acts as a resonant cavity. Therefore, vibration of the cone valve easily causes resonance throughout the valve, generating noise. This noise is usually accompanied by severe pressure fluctuations. (2) Noise Caused by Cavitation
When air is drawn into the oil for various reasons, or when the oil pressure is lower than atmospheric pressure, some of the air dissolved in the oil will precipitate and form bubbles. These bubbles are larger in low-pressure areas, but when they flow with the oil to high-pressure areas, they are compressed and their volume suddenly decreases or the bubbles disappear; conversely, if the volume is smaller in high-pressure areas, it suddenly increases when flowing to low-pressure areas. This rapid change in the volume of bubbles in the oil generates noise, and because this process occurs instantaneously, it will cause local hydraulic shock and vibration. The pilot valve port and main valve port of a pilot-operated relief valve experience significant changes in oil flow rate and pressure, making cavitation easy to occur, thus generating noise and vibration.
Main functions of the ATOS relief valve:
Constant pressure relief function: In a fixed-displacement pump throttling system, the fixed-displacement pump provides a constant flow rate. When the system pressure increases, the flow rate demand decreases. At this time, the relief valve opens, allowing excess flow to return to the oil tank, ensuring a constant inlet pressure (i.e., pump outlet pressure) (the valve opening usually fluctuates with pressure).
Pressure stabilization: The relief valve is connected in series in the return oil line, generating back pressure and increasing the smoothness of moving parts.
System unloading: A small-flow solenoid valve is connected in series with the remote control port of the relief valve. When the solenoid is energized, the remote control port of the relief valve connects to the oil tank, unloading the hydraulic pump. The relief valve then functions as an unloading valve.
Safety protection: The valve is closed during normal system operation. It only opens when the load exceeds the specified limit (system pressure exceeds the set pressure) for overload protection, preventing further pressure increases (typically, the set pressure of the relief valve is 10%~20% higher than the system's maximum operating pressure).
In practical applications, it is generally used as an unloading valve, a remote pressure regulating valve, a high/low pressure multi-stage control valve, a sequence valve, and to generate back pressure (connected in series in the return oil line).
Relief valves generally come in two structures: 1. Direct-acting relief valve; 2. Pilot-operated relief valve.
The main requirements for relief valves are: wide pressure regulation range, small pressure regulation deviation, small pressure fluctuation, sensitive operation, large overload capacity, and low noise.
ATOS Relief Valves
AGAM-10/10/100 34
AGAM-10/10/100-IX 230/50/60AC 34
AGAM-10/10/100-IX 24DC
AGAM-10/10/210
AGAM-10/10/210/V-IX 24DC
AGAM-10/10/210-IX 230/50/60AC
AGAM-10/10/210-IX 24DC
AGAM-10/10/210-IX 24DC 34/WG
AGAM-10/10/350 34
AGAM-10/10/350/V-IX 24DC
AGAM-10/10/350-1X 24DC 34 AGAM-10/100
AGAM-10/11/100/7PA-M-AO 24DC
AGAM-10/11/100-IX 230/50/60AC
AGAM-10/11/210-IX 230/50/60AC
AGAM-10/11/210-IX 24DC
AGAM-10/11/350/PA-GK-AO 24DC 22
AGAM-10/11/350-IX 110/50/60AC
AGAM-10/11/350-IX 24DC
AGAM-10/20/210/100-IX 24DC
AGAM-10/20/350/100-IX 230/50/60AC 34 AGAM-10/20/350/210/V-IX 230/50/60AC 34
AGAM-10/20/350/210-IX 230/50/60AC 34
AGAM-10/20/350/210-IX 24DC 34
AGAM-10/21/350/100-IX 24DC 34
AGAM-10/21/350/210-IX 230/50/60AC 34
AGAM-10/210
AGAM-10/210/V 34
AGAM-10/22/100/100-IX 24DC 34
AGAM-10/350
AGAM-10/50 34 AGAM-20/10/100/V-IX 24DC 53
AGAM-20/10/210/V-IX 24DC 53
AGAM-20/10/210-IX 230/50/60AC
AGAM-20/10/210-IX 24DC
AGAM-20/10/350-IX 230/50/60AC
AGAM-20/10/350-IX 24DC
AGAM-20/100
AGAM-20/11/210/M-AO 220 21
AGAM-20/11/210/V-IX 24DC 53
AGAM-20/11/210-IX 230/50/60AC AGAM-20/11/210-IX 24DC
