Coaxial Valves: Comprehensive Guide to Solenoid & Air Pilot Coax Valves

2/2 Way Normally Closed coaxial valve is in the fail-safe closed state.

This 2 way normally closed coaxial valve is in the rest or fail-safe position.

The control tube (2) through which the media (Blue) will flow and is pressed by a compression spring (3) into the valve seat (1).

The coaxial valve is in the closed state - no flow.

2/2 Way Normally Closed Coaxial Valve in the energised open state.

This 2 way normally closed coaxial valve is in the energised position.

By energising the electro magnet (4) an electromagnetic field is generated which moves the control tube (2) in an axial direction away from the valve seat (1) and so opens the flow passage. Due to the axial movement of the tube (2) a compression spring (3) is compressed.

When the electrical supply is removed and the electro magnet de-energised (4), the compressed spring (3) pushes against the control tube (2) back into ins initial position against the valve seat (1). The coaxial valve is again closed and there is no flow of media.

2/2 Way Normally Open coaxial valve is in the fail-safe open state. 

This 2 way normally open coaxial valve is in the rest or failsafe position.

In the fail-safe rest position, the control tube (2) through which the media flows, has the compression spring (3) mounted on the right hand side, keeping the tube (2) away from the seat seal (2), allowing the flow of media through the valve.

2/2 Way Normally Open coaxial valve is in the energised closed state.

This 2 way normally open coaxial valve is in the energised position.

With electrical power to the solenoid magnet (4) of an applied voltage, an electromagnetic field is generated, which pulls the control tube (2) in an axial direction against the valve seal (1) and thus closes the passage preventing the flow of media. At the same time the tube (2) compresses the spring (3) further.

With electrical power removed and the electro magnet (4) without power to generate electro magnetic field, the compression spring (3) pushes the control tube (2) back to its fail safe (original) position away from the valve seat (1). The valve opens again.

3/2 Way Normally Closed coaxial valve in the fail-safe closed state.

This 3 way normally closed coaxial valve is in the rest or fail-safe position.

With the control tube (2) through which the media (Blue) flows and is pressed against a compressed spring (3) against the valve seat (1).

The valve is constantly closed from inlet P to outlet A.

Flow is allowed from port P to exhaust port R.

3/2 Way Normally Closed coaxial valve in the energised open state.

This 3 way normally closed coaxial valve is in the energised position.

By energising the electro magnet (4) an electromagnetic field is generated that in turn moves the control tube (2) in an axial direction away from the valve seat (1) and so opens the flow passage from Inlet P to outlet A. The opposite side of the control tube (2) is pressed against the 3/2 valve seat (5) and closes the flow passage from A to R. Due to the axial movement of the tube (2) a compression spring (3) is compressed.

When you turn off the magnet i.e. remove the electrical supply and de-energise the electro magnet (4), the compressed spring (3) pushes against the control tube (2) back into its rest position against the valve seat (1). The coaxial valve is again closed from P to A and flow from P to R is thus open again.

3/2 Way Normally Open coaxial valve in the fail-safe open state.

This 3 way normally open coaxial valve is in the failsafe or rest position.

When a 3/2 way coaxial valve is in the rest or fail-safe position the control tube (2) through which the media (blue) will pass, is forced to the left by a compressed spring (3) against the 3/2 way valve seat (5), which in turn opens the passage from P to A and closes the flow path P to R.

3/2 Way Normally Open coaxial valve in the energised closed state.

This 3 way normally open coaxial valve is in the energised position.

With electrical power to the solenoid magnet (4) of an applied voltage an electromagnetic field is generated, which moves the media control tube (2) in an axial direction (right) away from the 3/2 valve seat (5) and opens the flow path from P to R. The other side of the control tube is pressed against the valve seat (1) and thus closes port A. Due to the shift of the tube (2) the return spring (3) is compressed further.

When you turn off the electrical power supply the electro magnet (4) allows the compression spring (3) to push the control tube (2) (left) back to its fail safe original position back against the 3/2 way valve seat (5) closing the connection from P to R and at the other end the tube moves against the valve seat (1) closing port A.

2/2 way normally closed air piloted coaxial valve in the failsafe closed state.

This 2 way normally closed air actuated coaxial valve is in the rest or fail position.

The control tube (2) through which the medium (blue) flows is pressed by a compression spring (3) against the seal of the valve seat (1). The valve is thus permanently closed.

If the valve is pilot operated by a 5/2 Way Pilot control valve, the control tube is pressed in addition to the spring, by means of control air (green) at port 2 into the seat. Port 4 is exhausted to atmosphere.

2/2 way normally closed air pilot coaxial valve in the actuated open state.

This 2 way normally closed air actuated coaxial valve is in the actuated position.

By supplying the control air at the port 4, the space in the cylinder is set under pressure, which pushes the control tube (2) in the axial direction away from the valve seat (1) and so releases the passage allowing flow. The space at port 2 is exhausted to atmosphere. Due to this shift in the valve tube, a compression spring (3) is compressed further.

When port 4 is vented to atmosphere, the compression spring (3) pushes the control tube (2) back to its initial position against the valve seat (1). The valve is then closed again - no flow.

2/2 way normally open air pilot coaxial valve in the failsafe open state.

This 2 way normally open air actuated coaxial valve is in the rest or failsafe position.

When the Normally Open valve is in the rest position, the control tube (2) through which the medium flows, is pressed by a compression spring (3), to the left and results in an open passage for flow of media. The valve is thus permanently opened.

If the valve is pilot operated by a Namur 5/2 Way Pilot valve, the control tube is pressed away in addition to the spring, by means of control air (green) on port 4 from this valve. The space at port 2 is exhausted to atmosphere.

2/2 way normally open air pilot coaxial valve in the energised state.

This 2 way normally open air actuated coaxial valve is in the actuated position.

If the space in the cylinder is filled through the port 4 with the control air (green), the control tube (2) moves in the axial direction towards the sealing of the valve seat (1), thus closing the passageway. The space at port 2 is vented to atmosphere. Due to this shift in the valve, the compression spring (3) is compressed further.

When air is released or vented from the port 4, the compression spring (3) shifts the tube (2), to the right and results in a closed passage (1) - no flow.

3/2 way normally closed air piloted coaxial valve in the failsafe closed state.

This 3 way normally closed air actuated coaxial valve is in the rest or fail position.

These externally controlled pneumatic valve is in the rest or fail safe position, with the control tube (2) through which the medium (blue) flows being pushed by a compressed spring (3) against the seal of the valve seat (1).

The valve is thus permanently closed from the input P to output A. From P to output R, the medium can be flow through the valve.

3/2 way normally closed air pilot coaxial valve in the actuated open state.

This 3 way normally closed air actuated coaxial valve is in the actuated position.

By supplying the compressed control air at the port 4, the space in the cylinder is set under pressure, which pushes the control tube (2) in the axial direction away from the valves seat (1) and so releases the flow path passage from P to A. The opposite side of the control tube is at the same time pressed in the 3/2 Way valve seat (4) and so closes the passage from A to R. Due to this shift in the valve, the return spring (3) is compressed.

When port 4 is exhausted to atmosphere, the compression spring (3) pushes the control tube (2) back to its initial position in the valve seat. The valve is then closed from P to A. Connection from P to R is thus open again.

3/2 way normally open air piloted coaxial valve in the failsafe open state.

This 3 way normally open air actuated coaxial valve is in the rest or fail position.

These externally controlled pneumatic valve is in the rest or fail safe position, with the control tube (2) through which the medium (blue) flows being pushed by a compressed spring (3) against the seal of the valve seat (1). The valve is thus permanently closed from the input P to output A. From P to output R, the medium can be flow through the valve.

When the Normally open valve is in the rest position, the control tube (2) through which the medium (blue) flows, is pressed by a compression spring (3), to the left away from valve seal (1) and results in an open passage P to A and in turn pushes against 3/2 way seal $4) thus closes the connection from P to R.

If the valve is pilot operated by a 5/2 Way Namur Pilot valve, the control tube is pressed away in addition to the spring, by means of control air (green) on port 2 from the valve. The space at port 4 is thus vented to atmosphere.

3/2 way normally open air piloted coaxial valve in the actuated closed  state.

This 3 way normally open air actuated coaxial valve is in the actuated position.

If the space in the cylinder is filled through the port 4 with the control air (green compressed air), the control tube (2) moves in the axial direction away from the 3/2-Way valve seat (4), and so opens the passage from P to R. The opposite side of the control tube is pressed at the same time into the valve seat (1) and thus closes the passage from P to A. Due to this tube shift in the valve, the return spring is compressed further.

When venting port 4, the return spring (3) shifts the control tube (2) back to its initial position away from the 3/2 valve seat. The valve is then open again.