BURKERT 20047735 (Type 6518) is a servo-assisted 3/2-way pneumatic solenoid valve. The valve width of 32 mm allows high flow rates. The valves work without a continuous air consumption and are used for the pneumatic control of double or single-acting actuators. The use of high quality materials makes it possible to use these valves in the open air and under chemical atmospheres. This specific model is an Ex mb variant featuring a 3-meter moulded wire cable and carries ATEX, IECEx, and UL approvals for hazardous locations.

General Technical Data

Product properties
Material
Seal	NBR, PUR
Body	Polyamide, reinforced glass-fibre
Threaded bushing	Brass (stainless steel on request)
Manual override	Standard
Orifice	DN 8
Circuit function	C (Normally closed)
Performance data
Compressed air quality	ISO 8573-1:2010, class 7.4.4
Duty cycle	100 % continuous operation
Medium data
Operating medium	Neutral medium (e.g. lubricated or oil-free compressed dry air)
Product connections
Electrical connection	3 m cable, moulded (Ex mb)
Pneumatic connection	Threaded G 1/4
Auxiliary pilot air port	M5
Approvals and conformities
Degree of protection	IP65
Explosion protection	ATEX, IECEx
North America	UL Listed for Hazardous Locations
Environment and installation
Installation position	As required, preferably with actuator upright

Ex mb Variant Specifications

Ex mb approval is achieved by fitting the valve with a corresponding push-over coil. The cable connection and the cable are permanently moulded to the coil.

Product properties
Weight	600 g
Switching time
Opening	20 ms
Closing	50 ms
Electrical data
Operating voltage	24 V DC
Voltage tolerance	± 10 %
Medium data
Medium temperature	-10 °C...+ 55 °C
Environment and installation
Ambient temperature	-25 °C...+ 50 °C

Temperature Limits

The maximum medium temperature must never exceed the permitted temperature class (T4: + 135 °C, T5: + 100 °C, T6: + 85 °C) minus 5 K.

Circuit Function

Symbol	Description
	Circuit function C (CF C) 3/2-way solenoid valve Servo-controlled Normally closed

Dimensions

Ex mb variant with moulded cable (3 m long)

Note: Dimensions in mm

Installation and Assembly

Basic Safety Instructions

Risk of injury due to high pressure and escaping medium. ▶ Switch off the pressure before working on the device or system. Vent or empty the lines.

Risk of injury from electric shock. ▶ Switch off the power supply before working on the device or system. Secure it against reactivation. ▶ Observe the applicable accident prevention and safety regulations for electrical devices.

Tightening torque for port connections

Observe the following tightening torques when screwing in the port connections. The specified tightening torque may vary depending on the sealing system.

Port size	Recommended tightening torque [Nm]	Maximum tightening torque [Nm]
G 1/4	4...7	20
M5 (auxiliary pilot air)	1...1.2	3

Ports

All ports are marked with numbers on the valve body. The meaning of the numbers is the same for each variant.

No.	Meaning	No.	Meaning
1	Pressure port	3, 5	Exhaust port
2, 4	Working port	12, 14	Pilot pressure port