Solenoid valve for air----VRA/VLA/VTA-Beijing Suntouch Thermprocess Equipment Co., Ltd

The VRA/VLA/VTA types are normally closed solenoid valves for cold combustion air regulation (open when energized). This type of device is suitable for high/low control of combustion air in industrial gas burners.

The valves are made of aluminum alloy die-cast, with a wide range for inlet/outlet connections from DN 20 up to DN 80.
Pipe connections meet group 2, according to EN161 requirements.
Suitable for use with cold combustion air (not for safety purposes).
Provided with two flow adjustments: minimum and maximum flow rate, for high/low operation.
Suitable for heavy duty cycle operation and for continuous service (100% ED).
The whole range can be provided in Ex-proof execution, for use in Zones 2 and 22, according to 94/9/EC Directive (ATEX).
The valve is supplied without an internal filter, because in many applications the air is very dirty and it should clog the filter in short time. It is provided with a special dust cover able to protect mechanical moving parts.
Provided with G1/4 pressure gauge on two sides in the inlet chamber, to connect manometers, pressure switches or other equipments. Flanged models are provided with gauges also in the
outlet chamber.
The coils are provided with terminal box or with ISO 4400 plug (optional). Both systems are provided with suitable cable gland to avoid water and dirty contamination.
All components are designed to withstand any mechanical, chemical and thermal condition occurring during typical service. Effective impregnation and surface treatments have been used
to improve mechanical sturdiness, sealing and resistance to corrosion of the components.
Valves are 100% tested by computerized testing machineries and are fully warranted.

Connections:

Gas threaded ISO 7-1 from Rp3/4 to Rp2½ Flanged PN16 – ISO 7005 from DN40 to DN80

Voltage rating:

230 VAC 50/60 Hz

110 VAC 50/60 Hz

24 VAC/DC

12 VAC/DC

Voltage tolerance: -15% / +10%

Power consumption see charts

Ambient temperature: -15°C / +60°C

Media temperature: +60°C Max.

Max. operating pressure: 200 mbar (20 kPa)

Flow capacity see charts

Operating time:

VRA: 1s opening/closing

VLA: ~4s opening / 1s closing

VTA: ~4s opening/closing

Protection class IP54 (EN 60529) (optional IP65)

Cable gland M20x1,5 (EN 50262) for terminal box

PG 9 for standard plug

Coil winding insulation Class H (200°C)

Coil thermal resistance Class F (155°C)

Materials in contact with media:

Aluminium alloy

Brass

Stainless steel

Plated steel

Anaerobic adhesive

Nitrile rubber (NBR)

Polytetrafluoroethylene (PTFE)

The VRA type valve is a fast opening/closing solenoid valve. The VLA type is a slow opening an fast closing solenoid valve. The VTA type is a slow opening/closing solenoid valve.

Both Min./Max. can be set from 0 to100%.

When not energized the spring works on the disc keeping the minimum passage of air. When powering the coil the valve opens, moving the disc to the maximum open position. When power is switched off the valve moves to the minimum position.