Burner Controls: Selection & Buying Guide

What Are Burner Controls?

Burner controls encompass every component that monitors, regulates and safely interrupts the gas or air supply to an industrial burner. They sit between the gas main and the burner head, forming a safety chain that must respond correctly to both normal operating conditions and fault states. In a typical train you will find a gas filter, a pressure regulator, one or more solenoid safety valves, a pressure switch, and—on larger installations—a tightness control unit that verifies valve integrity before each start.

3G Electric's catalog lists 497 burner-control products across eight leading OEM brands, giving procurement teams a single source for complete train assemblies or individual replacement parts.

Main Component Types

Gas Solenoid Safety Valves

Solenoid valves are the primary fuel shut-off devices. Two opening characteristics are available:

• Slow-opening (VAS …/LW, VAS …/LQ series): The valve ramps open gradually, limiting pressure surge and reducing ignition noise. Suitable for atmospheric and forced-draught burners where soft-light is required. Kromschroder's VAS 120R/LW (SKU KRO06028), VAS 240R/LQ (SKU KRO06035) and VAS 250R/LW (SKU KRO06038) are representative catalog items, all rated to 500 mbar upstream and fitted with a blue LED status indicator.
• Fast-opening (VAS …/NW, VAS …/NQ series): The valve opens at full speed for applications where rapid gas admission is required. The VAS 232R/NQ (SKU KRO06011), VAS 350R/NW (SKU KRO06020) and VAS 365R/NW (SKU KRO06022) share the same 500 mbar upstream pressure rating and blue LED indicator.

Both families offer integrated flow adjustment on selected models, eliminating the need for a separate throttle valve in the train.

Gas Filters

Particulate contamination from pipework causes premature valve seat wear and false pressure-switch trips. A gas filter upstream of the valve train is therefore mandatory on most installations. Kromschroder's GFK range uses 50 µm polypropylene foam elements in an AlSi housing and conforms to DIN 3386. Available connection sizes include Rp 1 (GFK 25 body: SKUs KRO02110, KRO02112) and Rp 1¼ (GFK 32 body: SKUs KRO02108, KRO02308). Check the filter's maximum allowable pressure against your supply pressure before specifying.

Pressure Switches

Pressure switches confirm that gas or combustion-air pressure is within the safe operating window. Kromschroder's DG series (SKUs KRO04108, KRO04208, KRO04230) meets EN 1854 class S and is independently approved to FM, UL, AGA and GOST-TR. The DG 6U/9 Z model (SKU KRO04230) is rated up to SIL 3 and Performance Level e—the highest functional-safety tier in EN 13849—making it suitable for demanding process-burner applications. Models cover overpressure, underpressure and differential-pressure sensing; confirm the required switching range from your burner datasheet.

Tightness Control Units

Tightness controllers automatically prove that both safety valves in a double-block arrangement are leak-tight before the burner is permitted to start. The Kromschroder 100–600 s unit (SKU KRO05016) offers an adjustable test timer of 100–600 s and uses a 5 mm connector. Tightness control is mandatory under EN 1643 for many gas categories and burner sizes; verify the applicable standard for your installation.

Gas Pressure Regulators

Regulators maintain a stable downstream pressure regardless of supply-pressure fluctuations. The Kromschroder VGBF 25R40-1 (SKU KRO01220) covers the VGBF 15–50 and VGBF 40–100 model families and uses a 12.5 × 1.5 mm impulse line. Confirm the required outlet pressure range and flow capacity (Kv value) from your burner manufacturer's specification.

Specification Comparison Table

Key Selection Criteria

• Valve opening speed: Specify slow-opening for atmospheric burners requiring soft-light; fast-opening where rapid gas admission is designed into the combustion sequence.
• Upstream pressure: Confirm the maximum supply pressure at the valve inlet. All VAS-series valves listed here are rated to 500 mbar; filters vary between 0.4 bar and 1 bar—do not exceed the filter's rated pressure.
• Connection size and type: Match DN size and thread standard (Rp, ISO flange) to existing pipework. Check the stamped marking on the valve body or filter housing.
• Functional safety level: Applications governed by EN 13849 or IEC 61508 require components with a declared SIL or PL rating. Kromschroder DG-series pressure switches are rated up to SIL 3 / PL e.
• Approvals: For export projects, verify the required regional approvals (FM and UL for North America, AGA for Australia, GOST-TR for Russia/CIS). The DG 150U/3 and DG 150U/6 carry all four.
• Integrated features: Valves with built-in flow adjustment (VAS 120R/LW, VAS 232R/NQ, VAS 250R/LW) reduce component count and potential leak points in the train.
• Filter element rating: The GFK range uses 50 µm polypropylene foam. If your gas quality is poor or pipework is old, consider a higher-filtration element—check Kromschroder's filter selection guide.
• Tightness control timer: Match the test cycle time to your burner management system's start sequence. The KRO05016 unit is field-adjustable from 100 s to 600 s.

Leading OEM Brands

3G Electric's burner-controls catalog is dominated by Kromschroder (173 products), the German specialist whose VAS valve, DG pressure-switch and GFK filter families are specified on a wide range of European and export burner OEM equipment. Satronic (101 products) and Siemens (96 products) supply burner management and ignition-control modules widely used in commercial heating. Brahma (64 products) covers solenoid valves and controls for light-commercial and industrial applications. Pactrol (27 products), Honeywell (20 products), SIT (11 products) and CBM (3 products) round out the range for specific OEM replacement requirements.

When sourcing a replacement part, always cross-reference the OEM brand and model number from the burner's wiring diagram or valve-train label rather than relying on physical appearance alone.

How to Source the Right Burner Control Component

1. Identify the failed or required component from the burner's wiring diagram, valve-train schematic or OEM parts list. Note the brand, model number and any suffix codes (e.g. /LW, /NQ, /6).
2. Record the key specifications: connection size, maximum upstream pressure, opening speed, safety rating and required approvals.
3. Search 3G Electric's catalog by brand, model number or SKU. With 497 burner-control products available to order, most Kromschroder, Satronic, Siemens, Brahma, Honeywell and SIT references are listed.
4. Request a quotation for confirmed lead time, quantity pricing and any export documentation required for your destination country.
5. Verify compatibility against the burner OEM's installation manual before fitting—particularly for tightness control units, where the test-timer setting must match the burner management system's start sequence.
6. Retain documentation: Keep the component datasheet and approval certificates on file for maintenance records and regulatory inspections.

Frequently Asked Questions

What is the difference between a slow-opening and a fast-opening gas solenoid valve?

A slow-opening valve (e.g. VAS …/LW or /LQ) ramps the gas flow gradually to reduce ignition shock and pressure surge. A fast-opening valve (e.g. VAS …/NW or /NQ) admits gas at full speed. The choice is dictated by the burner OEM's combustion sequence specification.

What upstream pressure are the Kromschroder VAS solenoid valves rated to?

All VAS-series solenoid valves listed in the 3G Electric catalog—including the VAS 120R/LW, VAS 232R/NQ, VAS 240R/LQ, VAS 250R/LW, VAS 350R/NW and VAS 365R/NW—are rated to a maximum upstream pressure of 500 mbar. Always verify against the specific product datasheet.

Which Kromschroder pressure switches carry SIL 3 / PL e ratings?

The DG 150U/3 (KRO04108), DG 150U/6 (KRO04208) and DG 6U/9 Z (KRO04230) are all rated SIL 3 / Performance Level e under EN 1854. They also hold FM, UL, AGA and GOST-TR approvals, making them suitable for international projects.

What filtration rating do the Kromschroder GFK gas filters use?

All GFK-series filters in the catalog use a 50 µm polypropylene foam element housed in an AlSi body conforming to DIN 3386. Connection sizes range from Rp 1 (DN 25) to Rp 1¼ (DN 32); maximum pressure varies by model between 0.4 bar and 1 bar.

When is a tightness control unit required?

Tightness control is required by EN 1643 on many gas burner installations to prove that both safety valves in a double-block arrangement are leak-tight before each start. Check the applicable national regulation and burner category for your installation. The Kromschroder 100–600 s unit (KRO05016) provides an adjustable test cycle.

How do I identify the correct replacement part for my burner?

Locate the burner's wiring diagram or valve-train label and record the OEM brand, full model number (including suffix codes) and key specs such as connection size and pressure rating. Search 3G Electric's catalog by model number or SKU, then request a quotation for lead time confirmation.

Are these burner control components available for international delivery?

Yes. 3G Electric supplies burner controls worldwide as an authorised distributor, handling logistics, customs documentation and export requirements. All items are available to order; confirmed lead times are provided at quotation stage.

Do Kromschroder VAS valves include integrated flow adjustment?

Selected models do. The VAS 120R/LW (KRO06028), VAS 232R/NQ (KRO06011) and VAS 250R/LW (KRO06038) all feature integrated flow adjustment, eliminating the need for a separate throttle valve in the gas train. Check the model suffix and datasheet to confirm this feature on any specific variant.