on video How do direct and indirect acting safety valves work?

How do direct and indirect acting safety valves work?

At rest, the spring keeps the valve sealed closed. There is no communication between the red (pressure) and blue (return) lines. Red line pressure is supplied through a pilot port on the poppet, on the side opposite the spring.

When the red pressure reaches a sufficient value to overcome the force of the spring, the valve will open and let the oil escape towards the blue line: the return. In this case, we say that we are laminating. Thus, the pressure in the red line will no longer exceed the spring rate value.

This type of pressure relief valve is said to be direct action: it is the red oil pressure which acts directly on the valve and the spring. Note that any back pressure on the return line will influence the set pressure.

Aperture range

This type of pressure relief valve has an opening range. A low flow rate (eg: 1L/min) will lift the valve by slightly compressing the setting spring, while a high flow rate (eg: 10L/min) will lift the valve by compressing the setting spring more strongly, therefore the pressure P2 reading on the pump discharge will be higher. Care must therefore be taken to calibrate this limiter according to the nominal flow rate passing through it.

 

How do direct and indirect acting safety valves work?

At rest, the spring keeps the valve sealed closed. There is no communication between the red (pressure) and blue (return) lines. Red line pressure is supplied through a pilot port on the poppet, on the side opposite the spring.

When the red pressure reaches a sufficient value to overcome the force of the spring, the valve will open and let the oil escape towards the blue line: the return. In this case, we say that we are laminating. Thus, the pressure in the red line will no longer exceed the spring rate value.

This type of pressure relief valve is said to be direct action: it is the red oil pressure which acts directly on the valve and the spring. Note that any back pressure on the return line will influence the set pressure.

Aperture range

This type of pressure relief valve has an opening range. A low flow rate (eg: 1L/min) will lift the valve by slightly compressing the setting spring, while a high flow rate (eg: 10L/min) will lift the valve by compressing the setting spring more strongly, therefore the pressure P2 reading on the pump discharge will be higher. Care must therefore be taken to calibrate this limiter according to the nominal flow rate passing through it.

 

How do direct and indirect acting safety valves work?

At rest, the spring keeps the valve sealed closed. There is no communication between the red (pressure) and blue (return) lines. Red line pressure is supplied through a pilot port on the poppet, on the side opposite the spring.

When the red pressure reaches a sufficient value to overcome the force of the spring, the valve will open and let the oil escape towards the blue line: the return. In this case, we say that we are laminating. Thus, the pressure in the red line will no longer exceed the spring rate value.

This type of pressure relief valve is said to be direct action: it is the red oil pressure which acts directly on the valve and the spring. Note that any back pressure on the return line will influence the set pressure.

Aperture range

This type of pressure relief valve has an opening range. A low flow rate (eg: 1L/min) will lift the valve by slightly compressing the setting spring, while a high flow rate (eg: 10L/min) will lift the valve by compressing the setting spring more strongly, therefore the pressure P2 reading on the pump discharge will be higher. Care must therefore be taken to calibrate this limiter according to the nominal flow rate passing through it.

 

How do direct and indirect acting safety valves work?

At rest, the spring keeps the valve sealed closed. There is no communication between the red (pressure) and blue (return) lines. Red line pressure is supplied through a pilot port on the poppet, on the side opposite the spring.

When the red pressure reaches a sufficient value to overcome the force of the spring, the valve will open and let the oil escape towards the blue line: the return. In this case, we say that we are laminating. Thus, the pressure in the red line will no longer exceed the spring rate value.

This type of pressure relief valve is said to be direct action: it is the red oil pressure which acts directly on the valve and the spring. Note that any back pressure on the return line will influence the set pressure.

Aperture range

This type of pressure relief valve has an opening range. A low flow rate (eg: 1L/min) will lift the valve by slightly compressing the setting spring, while a high flow rate (eg: 10L/min) will lift the valve by compressing the setting spring more strongly, therefore the pressure P2 reading on the pump discharge will be higher. Care must therefore be taken to calibrate this limiter according to the nominal flow rate passing through it.