3/2 Coaxial Solenoid Valve

3/2 way coaxial solenoid valve range.

3/2 way Coax solenoid controlled valves are available across a wide range options, these valves can 3/2 way coaxial solenoid valvebe chosen according to pressure range, various material of construction, several seal materials, orifice size for flow rate, port connection size and type according to individual system requirements to provide the best cost effective valve solution to meet each individual application.

Special options available: (03) PTFE sealing, (08) Manual Over Ride, (12) Vacuum Version, (15) Mounting Brackets, (10) Oil and Grease Free, (19) Position Feed Back, (29) Metal Terminal Box, (20) Connector with LED, (07) Special Connection, (06) Special Voltage.

You can view a typical technical data sheet here...

Basic Principle

How 3/2 coaxial solenoid valves work.

Valve working basics.

3/2 way coaxial solenoid valve normally closed

3/2 normally closed coaxial solenoid valve

Pressure: Flow P to A or P to R Maximum

Flow A to P or R to P 16 Bar

3/2 coaxial solenoid valve normally closed

Fail safe Closed -  Flow A to R, P to A Closed

3/2 coaxial solenoid valve energised

Energised Open, Flow P to A, A to R closed

     

3/2 way coaxial solenoid valve normally open

3/2 normally open coaxial solenoid valve

Pressure: Flow P to A or P to R Maximum

Flow A to P or R to P 16 Bar

3/2 coaxial solenoid valve normally open

Fail safe Open -  Flow P to A, P to R Closed
 3/2 coaxial solenoid valve normally open - energised
Energised Closed, Flow P to R, P to A closed

Normally Closed Function

How a Coaxial 3/2 way normally closed solenoid valve works.

symbol for 3/2 way normally closed

3/2 way normally closed symbol

The coaxial valve is in the fail-safe closed state.

This direct acting 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 coax valve - closed position

The coaxial valve is in the energised open state.

This direct acting valve is in the energised position, by energising the electro magnet (4) such as 24vdc, 24vac, 110vac, 230vac etc, 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 closed coax valve - open position

Normally Open Function

How a Coaxial 3/2 way normally open solenoid valve works.

symbol for 3/2 way normally open3/2 way normally open symbol

The coaxial valve is in the fail safe open state.

When a 3/2 way 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 coax valve - open position

The coaxial valve is in the energised closed state.

With electrical power to the solenoid magnet (4) of an applied voltage 24vdc, 24vac, 110vac or 230vac etc, 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.

 

3/2 way normally open coax valve - closed position

Technical Data Sheets

Click on the links below for the full PDF technical data sheets.
Model

Max Pressure (Bar)

Port SizesPort TypeOrifice Sizes (mm)

Body Material

Seal Options
370 40 1/4, 3/8, 1/2, 3/4, 1, 11/4, 11/2, 2"  BSP, NPT Thread or flange 10,15,20,25,32,40,50 Brass, AISI303 Stainless Steel or AISI316 Stainless Steel FKM, PTFE
371 64 1/4, 3/8, 1/2, 3/4, 1, 11/4, 11/2"   BSP, NPT Thread or flange 10,15,20,25,32 Brass, AISI303 Stainless Steel or AISI316 Stainless Steel FKM, PTFE
390 ATEX 20 1/4, 3/8, 1/2, 3/4"   BSP, NPT Thread or flange 10,15 Brass, AISI303 Stainless Steel or AISI316 Stainless Steel FKM, NBR, EPDM

3/2 Coaxial solenoid valve orifice sizes and flow rates.

3/2 way Coaxial solenoid actuated valves are available with a wide range of orifice or tube internal diameter sizes offering a variety of flow rates to suit the application at hand. As the stainless steel tube controls the media flow the diameter is the major factor in determining the flow coefficient of the valve in that the bigger the orifice (tube diameter) the higher the flow coefficient but also increases the size of the coaxial valve body and cost. Coaxial valves are offered with a range of orifice sizes for each port connection size for example a 3/4" BSP valve could be supplied with a 10mm, 15mm or 20mm tube offering different flow rates accordingly, the 10mm of course being smaller valve and less expensive than the 15mm or 20mm versions. There are logical limitations for orifice and port size combination, for example choosing a 1/2" port but requiring a 25mm orifice would be pointless as the flow restriction as the port entrance prevents any increase in flow beyond the 20mm tube flow limit.

3/2 Coax solenoid valve control voltages.

All coaxial solenoid controlled valves work on the principle of an electro magnet energised by a control voltage to move the internal tube into the open of closed position. The control voltage can be chosen according to each application but all coaxial valves operate on a DC (direct current) only as their design dictates that they are unable to handle AC 50/60Hz alternating current. To over come this problem with AC voltage supply the coax solenoid is equipped with a full bridge rectified electrical DIN43650A (Form A 28mm square) connector which will convert the AC supply current and output a rectified DC current to the valve. This simple solution, thanks to some clever circuitry within the connector allows for applications where 24vAC, 110vAC or 230vAC 50/60Hz is the preferred voltage and are easily converted to DC. Engineers must be aware that any coaxial valve used on an AC supply MUST HAVE this special rectified connector installed, otherwise the coaxial valve will hum or buzz loudly for a while before burning out the coil. The most commonly used coaxial valve voltages tend to be 24vDC and 230vAC (rectified), however options for 12vDC, 24vAC (rectified to 24vDC), 48vDC, 48vAC (rectified) and 110vAC (rectified to 110vDC) are available typically with a small additional cost.

Valve Options

Coax solenoid valves are available with a range of additional options to increase suitability for individual applications. Below we have detailed some of the more common options, however there is typically a vast additional range of custom options that most manufacturers can accommodate.

Mounting Brackets. (12)

To secure the valve body into place.

Coax mounting brackets 

Manual Over Ride. (08)

Allows for manual actuation of the valve.

 Coax valve manual over ride

Position Feed Back Switches, Open, Closed or Open and Closed volt free position switches.

Allows for remote signal confirmation of valve in open, closed or open and closed positions.

 Coax valve with position feed back switches

DIN 43650A Form A Electrical connector with LED.

LED light is ON when power is applied to the electrical connector.

 Coax valve with LED electrical connector
DIN 43650A Form A Electrical connector with M12x1mm electrical connection.  Coax valve with M12x1 electrical connector

DIN 43650A Form A power saving connector.

Electrical connector with PWM (Pulse Width Modulation) gives adjustable 11% to 89% power reduction after initial inrush current. Reduces power consumption and reduces heat build up. when fitted at factory connector will be installed and set up for optimal performance.

Coax valve with power saving connector