Dungs GW A6 Compact Pressure Switch for Gas and Air
Overview
The Dungs GW A6 is a compact, adjustable pressure switch for gas, air, flue gas and exhaust gas, built to EN 1854 class S for use in combustion plants. It switches an electrical circuit on, off or over when the measured pressure moves above or below a setpoint chosen on a scaled adjusting wheel. Because the Dungs GW A6 combines a small aluminium die-cast body, an integrated test nipple and a standard plug connector, it has become one of the most common pressure switches on burner gas trains, boiler combustion air fans and ventilation equipment.
Seven Star LLC supplies the Dungs GW A6 to boiler service companies, burner manufacturers, HVAC contractors and plant maintenance departments throughout Oman and the GCC. As a trusted supplier with engineering support in Muscat, we help customers identify the right range from the nameplate of an installed switch, which shortens downtime when a minimum gas pressure switch or air proving switch fails on a running plant.
Operating Principle
The switch is a single-acting unit in the overpressure range. Pressure acts on an NBR diaphragm whose force is compared with an adjustable spring set by the scaled wheel. When pressure increases past the setpoint, contact 1 (NC) opens and contact 2 (NO) closes; when pressure falls, the opposite happens. The Dungs GW A6 operates without any power supply, so the pressure signal itself drives the silver changeover contact, and the switching difference between the upper and lower switching pressure depends on the selected range.
The standard GW A6 has a short response time to pressure changes. The GW A6/1 version adds a damping nozzle in the pressure connection, which slows the response to short-term pressure fluctuations; this is useful on fan suction or discharge points and on gas lines where pulsation could otherwise cause nuisance burner lockouts. Two GW A6 switches can also be flanged together as a double pressure switch, fed from the same medium but with two independent setpoints.
Engineering Design of the Dungs GW A6
The housing is aluminium die cast, the switch part is polyamide, the diaphragm is NBR and the contacts are silver. The standard pressure connection (V0) is a G 1/4 internal thread centrally on the housing bottom, and the special V3 design adds a second G 1/4 thread on the right side. A test nipple with a 9 mm diameter is integrated in the metal housing so a technician can check the actual pressure at the switch during commissioning.
Electrical connection uses a 3-pin terminal connector for line sockets to DIN EN 175 301-803, protection-insulated without ground connection, giving IP 54. The Dungs GW A6 switches AC voltages from 24 to 250 V and DC voltages from 24 to 48 V. Standard installation is with the diaphragm vertical; if mounted horizontally the switching point shifts by about ±0.6 mbar for GW 3 to 50 A6, ±1 mbar for GW 150 A6 and ±3 mbar for GW 500 A6, which the engineer should allow for during setting.
Key Features
The Dungs GW A6 offers these practical benefits on burners and air handling equipment:
- The switch is approved to EN 1854 class S under the EU Gas Appliances Regulation and Pressure Equipment Directive.
- Five setting ranges cover 1 mbar up to 500 mbar, from fan differential monitoring to gas supply pressure.
- The changeover contact provides NC and NO functions from one device for low- or high-pressure alarms.
- A test nipple integrated in the metal housing allows pressure verification without extra fittings.
- The GW A6/1 damping nozzle version reduces nuisance switching on pulsating pressure.
- Mounting kits allow fitting directly to Dungs SV solenoid valves or pairing two switches as a double pressure switch.
- The switch needs no auxiliary power and handles up to 10 A AC nominal current on most ranges.
- Ambient and medium temperature range is −15°C to +70°C, suitable for plant rooms and rooftop units.
Industrial Applications
Typical uses of the Dungs GW A6 include minimum gas pressure monitoring upstream of burner valves, maximum gas pressure protection downstream of regulators, combustion air proving on fan-assisted burners, and filter or fan pressure monitoring in ventilation and air-conditioning plant. It is suitable for gases of families 1, 2 and 3 and other neutral gaseous media, so the same switch serves natural gas, LPG vapour and air duties.
In Oman these switches are found in hotel and hospital boiler houses in Muscat, industrial kitchens and bakeries, district cooling auxiliary systems and process heaters in the Sohar and Salalah free zones. Seven Star LLC supports these installations with genuine Dungs GW A6 switches and related gas-train parts such as the Dungs SV-D 505 safety solenoid valve, the DUNGS DMV-D 507/11 double solenoid valve and the DUNGS VPS 504 valve proving system, giving GCC maintenance teams one source for burner safety components.
Technical Specifications
Key Dungs GW A6 data from the manufacturer datasheet are listed below:
| Parameter | Specification |
|---|---|
| Model | Dungs GW 3 / 10 / 50 / 150 / 500 A6 and GW 50 / 150 / 500 A6/1 |
| Setting ranges | 1–3, 2–10, 5–50, 5–150, 100–500 mbar |
| Max. operating pressure | 500 mbar (GW 3–150 A6); 1000 mbar (GW 500 A6) |
| Standard / class | EN 1854, pressure switch class S |
| Pressure connection | G 1/4 internal thread (V0 bottom; V3 additional side) |
| Test nipple | Integrated, Ø9 mm |
| Switching voltage | AC 24–250 V; DC 24–48 V |
| Nominal current | 10 A AC (GW 10–500 A6); 6 A AC (GW 3 A6) |
| Switching current | Max. 6 A at cos φ 1, 3 A at cos φ 0.6 (GW 10–500 A6); DC max. 1 A |
| Setting tolerance | ±15% of setpoint |
| Temperature | Ambient and medium −15°C to +70°C; storage −30°C to +80°C |
| Materials | Aluminium die-cast housing, polyamide switch part, NBR diaphragm, Ag contacts |
| Protection | IP 54, connector to DIN EN 175 301-803 |
How to Order
To request a quotation for the Dungs GW A6, send Seven Star LLC an RFQ with the switch type and range, the order number from the label if available, and any mounting kit you need. Our instrumentation division in Muscat confirms the selection, checks availability and lead time, and shares the manufacturer datasheet for download. Seven Star LLC supplies genuine Dungs GW A6 compact pressure switches with engineering support for burner, boiler and HVAC projects in Oman and the wider GCC.
- Datasheet Dungs GW A6 / GW A6/1 Datasheet (manufacturer, Ed. 2024.08, No. 229 544) Download
DUNGS product families listed here
The listed DUNGS gas valves and controls make up most of a burner gas train. The FRS is a spring-loaded gas pressure regulator in sizes from Rp 3/8 to DN 150. The GW A6 is a compact pressure switch for gas and air. DMV-D double solenoid valves, such as the DMV-D 507/11 and DMV-D 5125/11, combine two safety shut-off valves in one body, and the SV-D is a single safety solenoid valve. The MB-DLE 405 to 412 B01 GasMultiBloc integrates a filter, a regulator and two valves in one compact unit. The VPS 504 is a valve proving system that tests the tightness of the two shut-off valves before burner start.Where DUNGS equipment is used
DUNGS combustion controls are fitted to steam and hot water boilers, thermal oil heaters, air heaters, dryers, ovens, kilns and furnaces, and to the fuel gas lines of gas engines. Buyers in the GCC typically need them as replacements on packaged burners in food plants, laundries, hospitals and building plant rooms.Ordering DUNGS parts: what we need
Send the full type designation and the six-digit article number from the nameplate, for example VPS 504 S04 with 219881, a 230 V version. Add the coil voltage and frequency, the connection (Rp thread or flange DN), and the maximum inlet pressure. For an FRS regulator, state the outlet pressure and the spring range or spring color. For a GW pressure switch, state the setting range, which is part of the type name. For a MultiBloc, say whether operation is single-stage or two-stage. The burner make and model help us confirm the match.Browse DUNGS products by category: Solenoid Valve.
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