BURKERT 332730 (Type 8745) is a Mass Flow Controller (MFC) specifically configured for NH3 ammonia with a nominal flow rate of 20.00 Nm3/h. It features a G 1/4" internal thread connection, operates on 24 V DC, and utilizes PROFINET for Industrial Ethernet communication. The Type 8745 family is suitable for controlling the mass flow of large gas quantities and can be configured as a Mass Flow Meter (MFM) or MFC according to demand.

The thermal inline sensor located directly in the main gas stream achieves very fast response times with minimal pressure loss. As the actuator, a Bürkert direct-acting proportional valve guarantees high response sensitivity.

General Technical Data

Property	Description
Seal Material	FKM or EPDM (depending on gas)
Housing Material	PC (polycarbonate)
Base Block Material	Aluminium or stainless steel 1.4404/316L
Wetted Parts (Sensor)	Stainless steel 1.4404/316L, Al₂O₃, PPS GF40, epoxy resin, silicon, silicon nitride
Operating Voltage	24 V DC (±10% voltage tolerance, ±2% residual ripple)
Operating Medium	Neutral, pure gases (configured for NH3 ammonia)
Medium Temperature	-10 °C to +70 °C (-10 °C to +60 °C with oxygen)
Digital Communication	Industrial Ethernet: PROFINET (for SKU 332730)
Port Connection	G 1/4" internal thread (for SKU 332730)
Degree of Protection	IP20

Variants and Performance

As an MFC, Type 8745 is available in two main variants:

Variant with Electromagnetic Proportional Valve

• Valve Position: Normally closed
• Measuring Accuracy: ±1.5% MV ±0.3% FS (under calibration conditions)
• Settling Time (t95): < 500 ms
• Power Consumption: Max. 12.5...31.5 W (as MFC, depending on valve type)

Variant with Electromotive Proportional Valve Especially suitable for applications with high inlet pressures of up to 22 bar or high flow rates at a low pressure drop. The motor’s power consumption to hold a specific opening position is nearly zero.

• Valve Position: Normally closed
• Measuring Accuracy: ± 2% MV ± 0.5% FS (under calibration conditions)
• Settling Time (t95): < 5 s
• Power Consumption: Max. 12 W (as MFC)

Approvals and Conformities

• North America (USA/Canada): Optional UL Listed (UL 61010-1, CAN/CSA-C22.2 No. 61010-1).
• Foods and Beverages/Hygiene: FDA compliance (Code of Federal Regulations), USP (United States Pharmacopeial Convention) biocompatibility, and EC Regulation 1935/2004 compliance available depending on variable codes.
• Oxygen: Optional suitability for gaseous oxygen.

Dimensions

Small nominal flow rates, with internal thread

Thread (A)	Thread depth [mm]
G 1/4	12
NPT 1/4	11
G 3/8	12
NPT 3/8	11
G 1/2	15
NPT 1/2	14
G 3/4	16
NPT 3/4	15

Product Connections

Industrial Ethernet (PROFINET)

Pin	Assignment
1	FE (functional earth)
2	DGND
3	24 V

Pin	Assignment
1	TX +
2	TX -
3	RX +
6	RX -
Housing	Shielding

Performance Specifications

MFM Pressure Loss Diagram The diagram shows an example of the pressure loss curves with air flowing through. To determine the pressure loss of other gases, the corresponding air equivalent must first be calculated.

Nominal Flow Rate of Typical Gases

Gas	Min. QN [l/min]	Max. QN [l/min]
Ammonia	8	1000
Air	20	2500
Nitrogen	20	2500
Oxygen	20	2500

INFO

All values refer to 1013.25 mbar abs and 273.15 K (0 °C).

Derating Diagram for Electromotive Variants

Measurement Principle

This sensor works as a hot-film anemometer in the CTA operational mode (Constant Temperature Anemometer). Two resistors with a precisely specified temperature coefficient located directly in the media flow and three further resistors are connected to form a measuring bridge. The heating current required to maintain a specified excess temperature is a measure of the heat dissipation and represents the primary measured variable.

Safety Information

WARNING

Electrostatically sensitive components and assemblies The device contains electronic components that are susceptible to the effects of electrostatic discharging (ESD). Meet the requirements specified by EN 61340-5-1 to minimize or avoid the possibility of damage.

Medium under pressure Medium under pressure can seriously injure people. Before working on the device or system, switch off the pressure. Vent or empty the lines.