Welcome to Coax-Valve.com

2/2 way Coaxial Solenoid Valve3/2 way coaxial solenoid valveThis is a Coax Valve UK based dedicated website for all solenoid operated and pneumatically operated 2/2 way and 3/2 way axial valves that will constantly evolve and be updated as the free knowledge base, information centre and guide on how coaxial valves work, their uses and various methods of operation and functionality.

2 way coax pneumatic valveWith so many options of choice for Coaxial valves such as weather it is solenoid 3/2 way coax pneumatic valveoperated (electro magnet), pneumatically operated, 2/2 way or 3/2 way, normally open or normally closed, a vast array of materials of construction, sealing, orifice and port size and type, can leave some users confused and disorientated.

All coaxial valves are direct acting in principle and thus will work from zero pressure which means the valve will operate without the need for pressure differential and are no susceptible to back pressures caused by spray nozzles, pressure control valves or other down stream equipment.

A coaxial valve works utilising an internal laterally movable hollow stainless steel tube which controls or diverts the flow of media passing through the valve body. The internal coax tube is typically 316 stainless steel which offers greater corrosion, wear and chemical resistance making it suitable for a wide range of inert, aggressive, corrosive, contaminated, abrasive thick glutinous liquid or gas media.

The coaxial tube is secured in place and sealed by either PTFE, NBR, EPDM or FKM O rings which allow lateral tube movement (left to right) and also prevent the media passing through the valve from contacting any other coaxial valve internal parts.

The tube ends will seal against FKM, NBR, EPDM or even PTFE gasket of choice and will prevent flow  or by moving away from this seal will allow the flow of liquid or gas media.

This internal axial moving tube can be moved laterally or coaxially by either electromagnetic solenoid controller with an applied electrical voltage or pneumatically by external compressed air or gas stand alone or namur mount pilot controller.

WE have detailed below the three main types of coaxial valve, 2/2 way solenoid controlled, 3/2 way solenoid controlled, 2/2 way pneumatically controlled and 3/2 way pneumatically controlled. Please revert to each section for explanation of each functionality.

2/2 Way Coax Solenoid Valves

2/2 Way Coaxial Solenoid Valves.

2/2 way Coaxial Solenoid Valve2 port 2 position solenoid actuated coaxial valves have one inlet port and one outlet port with two possible valve positions, either open or closed. These two positions can be either be:

Fail safe closed (normally closed) that prevent the flow of media requiring electrical power 24vdc or 230vac etc to open or

Fail-safe open (normally open) that allow the flow of media but requires electrical power 24vdc or 230vac etc or signal to close.

The method of operation is with an electro magnet or solenoid coil around an internal stainless armature and tube assembly. The electro magnetic coil simply converts the electrical energy supplied into a magnetic field that can laterally move this internal tube towards or away from a sealing face thus changing the state of the valve i.e. closed to open or open to closed. 

2/2 way coaxial solenoid valves are available in a wide range of port or connections sizes and types. The most commonly used are BSP (British Standard Pipe) threaded valves what are typically used within the European market or NPT (National Pipe Taper) thread typically for the American market, with additional options for flanged ends according to flange size, flange type and flange pressure ratings.

3/2 Way Coax Solenoid Valves

3/2 Way Coaxial Solenoid Valves.

3/2 way coaxial solenoid valve

3 port 2 position coaxial valves have one inlet port and two outlet ports with two positions either open or closed. There are two options here either:

Fail safe closed (normally closed) that prevents the flow of media across the valve right port to left port , but is open right port through to the downward exhaust port.

When energised 24vdc or 230vac etc the internal tube moves laterally allowing flow from right port through to left port, but in turn closes the down ward exhaust port.

Fail-safe open (normally open) that allows the flow of media across the valve right port through to left port, but is closed to the downward exhaust port.

When energised 24vdc or 230vac etc the internal tube moves laterally closing the left port but in turn allowing from from the right port through to the exhaust downward port.

The method of operation is with an electro magnet or solenoid coil, which simply converts any electrical signal into a magnetic field to move the internal tube laterally away from or against a sealing face to change the state of the valve from closed or open position.

3/2 way coaxial solenoid valves are available in a wide range of port connection sizes and types. The most commonly used are BSP parallel thread for the UK and European markets, NPT tapered thread for the American markets or flanged connections such as PN16, PN40 and PN100 according to flange diameter DN (Diameter Nominale) and of course the flange pressure ratings.

2/2 Way Pneumatic Coax Valves

2/2 Way Coax Pneumatic Valves.

2 port 2 position compressed air actuated or pneumatically controlled valves have one inlet port and 2 way coax pneumatic valveone outlet port with two possible positions, either open or closed. These two positions can be either:

Fail-safe closed (normally closed) that prevent the flow of media requiring a compressed air signal 3 to 8 bar to open to allow flow across the valve.

Fail safe open (normally open) that allow the flow of media but require a compressed air signal 3 to 8 bar to close the valve to prevent flow across the valve.

The method of operation is with an external supply of clean compressed air typically this is between 3 to 8 bar which is fed into the valve body via two external pilot holes, which are usually surrounded by four additional mounting holes for a namur interface mounting of external solenoid control 5/2 way valve to control the compressed air supply and in turn control the coaxial valve function.

2/2 way coax compressed air driven valves are available in a wide range of port thread sizes and type to suit each application. The most commonly used for the UK and Euro-zone are BSP British standard pipe sometimes referred to as a G thread with options for NPT National Pipe Taper thread for the USA and Canada markets. Additional connection options such as flange PN16 16 bar rated, PN40 40 bar rated and PN100 100 Bar rated are available in sizes ranging from DN10 (10mm) to DN50 (50mm).

3/2 Way Pneumatic Coax Valves

3/2 Way Coax Pneumatic Valve

3 port 2 position coaxial valves have one inlet port and two outlet ports with two positions either 3/2 air operated coaxial valveopen or closed. There are two options here either:

Fail safe closed (normally closed) that prevents the flow of media across the valve right port to left port , but is open right port to the downward exhaust port.

When actuated with 3 to 8 bar compressed air the internal tube moves laterally allowing flow from right port to left port, but in turn closes the down ward exhaust port.

Fail-safe open (normally open) that allows the flow of media across the valve right port to left port, but is closed to the downward exhaust port.

When actuated with 3 to 8 bar compressed air the internal tube moves laterally closing the left port but in turn allowing from from the right port to the exhaust downward port.

The method of operation is pneumatic with an external supply of clean compressed air between 3 to 8 bar which is fed into the valve body via two external pilot holes in the coax valve body, these are typically surrounded by four additional mounting holes for namur interface mounting of external 5/2 solenoid control valve that controls the compressed air supply by means of electrical signal to control the coax valve function.

3/2 way coax air actuated valves are available in a wide range of port thread sizes and type to suit each application. The most commonly used for the UK and Euro-zone are BSP British standard pipe sometimes referred to as a G thread with options for NPT National Pipe Taper thread for the USA and Canada markets. Additional connection options such as flange PN16 16 bar rated, PN40 40 bar rated and PN100 100 Bar rated are available in sizes ranging from DN10 (10mm) to DN50 (50mm).

Modular Systems

Modular Coax Valve Systems.

Coaxial solenoid operated valves can be mounted or assembled and grouped coax solenoid valves manifold systemtogether to create a single shared manifold system. This modular technology has become a key component for process control systems where two or more coaxial solenoid valves can be used share either a common inlet or common outlet without the need for additional pipework and fittings, reducing space and increasing functionality.

Combinations of 2/2 way normally open and 2-way normally closed and 3/2 way diverting coaxial valves can be mounted to the same manifold system, even with a range of orifice sizes offering different flow characteristics for each valve. So for example if valve 1 had 10mm orifice, valve 2 15mm orifice and valve 3 and 20mm orifice then various flows can be achieved offering either reduced or increased flow to specific equipment according to system requirements.