Kromschröder VAD Pressure Regulator with Solenoid Valve

Kromschröder VAD is a Class A constant-pressure gas governor with an integrated Class A safety solenoid valve, part of Kromschröder’s (Honeywell Thermal Solutions) valVario series. This page covers the VAD code only. Sibling codes in the series: VAG (fixed 1:1 air/gas ratio control), VAV (variable air/gas ratio 0.6:1–3:1), VAH (flow rate regulator with solenoid valve) and VRH (flow rate regulator without solenoid valve). Unlike those, the VAD holds a constant outlet pressure set by the control spring, not by an air pressure.

Specifications

• Function: shut-off and precise pressure control using servo technology; the nominal outlet pressure pd is set by the control spring.
• Outlet pressure: VAD..-25: 2.5–25 mbar; VAD..-50: 20–50 mbar; VAD..-100: 35–100 mbar.
• Furnace/combustion chamber pressure (-20 to +20 mbar) can be connected to the psa port to keep burner capacity constant when furnace pressure fluctuates.
• Max. inlet pressure 500 mbar (7 psig); 350 mbar for the ANSI/CSA version.
• Sizes 1–3: VAD 115 (DN 15), 120 (DN 20), 125 (DN 25), 240 (DN 40), 350 (DN 50). Rp thread to ISO 7-1 or NPT; ISO 7005 / ANSI flange on 240 and 350.
• Power supply: 230, 200, 120, 100 V AC (+10/-15%, 50/60 Hz) or 24 V DC (±20%). Coil 25 W (size 1), 36–40 W (sizes 2, 3); duty cycle 100%.
• Quick opening/closing (VAD../N): opening ≤ 1 s, closing < 1 s. The valve is closed when power is off.
• Gases: natural gas, gaseous LPG, biogas (max. 0.1% by volume H2S), hydrogen or clean air; the gas must be clean and dry.
• Valve seat: size 115 has the reduced valve seat (code B), the other sizes the standard seat (code A).
• Aluminium housing, NBR seal; ambient temperature -20 to +60°C, IP 65.

Dimensions and weight (Rp thread version)

The NPT version (NPT thread, ANSI flange) has its own dimension table in the document (section 9.2). ISO flanges exist on sizes 240 and 350 only.

Difference from VAG, VAV, VAH, VRH

• Versus VAG and VAV: the VAD regulates to a fixed set value from the control spring (three ranges -25, -50, -100), whereas VAG and VAV follow an air control pressure and therefore need an air control line (psa).
• Versus VAH and VRH: the VAD regulates pressure; VAH/VRH regulate gas flow rate in proportion to air flow rate measured across an orifice.
• The VAD has an integrated safety solenoid valve and closes when power is cut, like VAG, VAV and VAH; the VRH has no solenoid valve.

Applications

The valVario series is used in gas control and safety systems in the iron, steel, glass and ceramics industries, and in residential or commercial heat generation such as the packaging, paper and food industries. The VAD is used on excess-air burners, atmospheric burners and single-stage forced-draught burners; the document shows a pressure regulator on excess-air burners in the ceramics industry as an example.

Standards / Certification

• Class A pressure regulator to EN 88-1:2011+A1:2016; Class A, Group 2 safety valve to EN 13611 and EN 161:2011+A3:2013; EN 126:2012; EN 1854:2010 (per the manufacturer’s declaration of conformity for VAD/VAG/VAV/VAH/VRH sizes 1–3).
• UKCA: BS EN 88-1:2011, EN 126:2012, EN 161:2011+A3:2013.
• FM (Class 7400 and 7411; NFPA 85, NFPA 86), ANSI Z21.21 / CSA 6.5 (ANSI/CSA), UL 429 (120 V AC version), AGA (no. 5319). FM, ANSI/CSA and AGA do not apply to the 100 V AC and 200 V AC versions.
• Suitable for systems up to SIL 3 (EN 61508) and PL e (ISO 13849): single channel (HFT = 0) up to SIL 2 / PL d; SIL 3 / PL e with two redundant devices (HFT = 1) when the whole system meets the requirements.

Compatibility / Installation

• Install a filter upstream of the system; with air as the medium also fit an activated carbon filter. Keep sealing material and thread cuttings out of the valve housing.
• Black solenoid actuator vertical or tilted up to horizontal, not upside down. Leave at least 25 cm above the actuator and 20 mm from masonry.
• Inlet pu and outlet pd can be measured on both sides of the body; an external impulse line can replace the pd test point for better accuracy.
• Accessories: pressure switch DG..C, bypass/pilot gas valve VAS 1 or VBY 8 (VBY 8 for size 1), tightness control TC, test nipples, closed position switch (codes S, G).

What to send for a quote

To quote quickly and against the right code, please send:

• full type code (for example VAD with size 1-3 / DN, Rp or NPT thread or ISO flange)
• required outlet pressure range (-25, -50 or -100) or set pressure
• coil voltage (230, 200, 120, 100 V AC or 24 V DC) and whether a closed position switch is needed
• gas type (natural gas, gaseous LPG, biogas, hydrogen or clean air), inlet pressure and required flow rate
• quantity

CAD replies with a quote within 24 working hours.

Technical documentation (datasheet)

Kromschröder: Technical Information VAD, VAG, VAH, VAV, VRH, VCD, VCG, VCV, VCH (English, edition 08.23). This is the manufacturer’s single document for the whole series; the data for VAD is in the matching sections.