2/2 Coax Pneumatic Valve

Basic Principle

How 2/2 coaxial pneumatic valves work.

Valve working basics.

2/2 normally closed coaxial pneumatic valve Pressure: Flow P to A maximum pressure Flow A to P 16 Bar	Fail-safe Closed - No Flow	Actuated Open - Full Flow
2/2 normally open coaxial pneumatic valve Pressure: Flow P to A maximum pressure Flow A to P 16 Bar	Fail safe Open - Full Flow	Actuated Closed - No Flow

Technical Data Sheets

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

Model	Pressure (Bar)	Port Sizes	Port Type	Orifice Sizes (mm)	Body Material	Sealing
280	64	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 or 316 Stainless steel, Galvanised or nickel plated steel	FKM,NBR,EPDM
280X	64	1/4, 3/8, 1/2, 3/4, 1, 11/4, 11/2, 2"	Manifold	10,15,20,25,32,40,50	Brass, AISI303 or 316 Stainless steel, Galvanised or nickel plated steel	FKM,NBR,EPDM
281	120	1/4, 3/8, 1/2, 3/4, 1, 11/4, 11/2, 2"	BSP, NPT Thread or flange	10,15,20,25,32	Brass, AISI303 or 316 Stainless steel, Galvanised or nickel plated steel	FKM,NBR,EPDM
281X	120	1/4, 3/8, 1/2, 3/4, 1, 11/4, 11/2", Modular System	Manifold	10,15,20,25,32	Brass, AISI303 or 316 Stainless steel, Galvanised or nickel plated steel	FKM,NBR,EPDM
282	160	1/4, 3/8, 1/2, 3/4, 1, 11/4"	BSP, NPT Thread or flange	10,15,20,25	Brass, AISI303 or 316 Stainless steel, Galvanised or nickel plated steel	FKM,NBR,EPDM
282X	160	1/4, 3/8, 1/2, 3/4, 1 and 11/4", Modular System	Manifold	10,15,20,25	Brass, AISI303 or 316 Stainless steel, Galvanised or nickel plated steel	FKM,NBR,EPDM
283	200	3/8, 1/2, 3/4	BSP, NPT Thread or flange	15	Brass, AISI303 or 316 Stainless steel	FKM,NBR,EPDM
283X	200	3/8, 1/2, 3/4, Modular system	Manifold	15	Brass, AISI303 or 316 Stainless steel	FKM,NBR,EPDM
286	40	3/8		8	Brass	FKM,NBR,EPDM
286X	40	3/8	Manifold	8	Brass	FKM,NBR,EPDM

2/2 Coaxial air valve orifice sizes and flow rates.

Coax air operated valves are available with a wide range of orifice sizes offering users a choice of various flow rate coefficients for each port connection size. This orifice or internal flow path diameter relates to an internal tube of flow path diameter, so the larger the tube the higher the flow rate through the coaxial valve although there are some limitations. These limits relate the limitations of the port or connection size as having a larger internal tube orifice with a smaller connecting port the flow will be limited by the smaller port size, which is therefore uneconomical and an expensive mistake as the valve body increases in size and cost in relation to the orifice size too. The bonus here is that manufacturers will not typically supply coaxial valves outside the parameters of sound engineering practise and would probably not have designed any irrational options anyway. Another useful point is that for each orifice size typically a range of port sizes will be available for the same price, so for example a 1" BSP port may be available with 15mm, 20mm and 25mm internal tube diameters or orifice sizes offering different flow rates, valve dimensions and of course prices.

2/2 coaxial valve air pilot controllers.

Air pilot control valves or Namur mount solenoid valves are designed to bolt directly onto any air operated coax valve body that has namur interface offering an electrical control of the compressed air supply to open and or close the main air actuated valve. The two ports with the O ring seals will line up and seal against a namur interface valve, with bolts to secure this valve in place. Typically a compressed air supply is connected to the central air inlet port of the solenoid valve (see picture on right centre port of the three visible ports on the side), the other two ports either side are the exhaust ports.

These solenoid control valves are electrically actuated, require only a small amount of power typically 4.5 watts, are available across a broad range of voltages from 6vdc, 12vdc, 24vdc, 48vdc, 110vdc, 220vdc and 12vac, 24vac, 48vac, 110vac and 230vac either IP65 safe area or ATEX EEx mIIT4.