Solenoid valves for combustion air regulation
The VRA/VLA/VTA types are normally closed solenoid valves for cold combustion air regulation. When the coil is not energized the spring works on the disc, keeping the adjusted 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.This type of device is suitable for high/low stage control of combustion air in industrial gas burners. (qualified for continuous service- 100% ED).
Feature
- 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 operation).
- Provided with two flow adjustments: minimum and maximum flow rate, for high/low operation.
- Suitable for cycle operation and qualified for continuous service (100% ED).
- 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 seal 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.
Specification
- 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: ISO 20 (EN 50262) for terminal box,PG 9for 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)
Dimension
