Slow-open Solenoid Valve----VML-Beijing Suntouch Thermprocess Equipment Co., Ltd

The VML type valve is a slow opening single-stage solenoid valve, normally closed (open when energized). This type of device is suitable for air or gas blocking and releasing controls, required in gas power burners, atmospheric gas boilers, industrial kilns and others gas consuming appliances.

The valves are made of aluminum alloy die-cast, with a wide range for inlet/outlet connections from DN10 up to DN80.
Pipe connections meet group 2 and backpressure sealing is compliant with class A, according to EN161 requirements.
Suitable for use with air and non-aggressive gases included in the 1, 2 and 3 families (EN 437).
Special versions for aggressive gases (Biogas, COG).
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 open only when energized: if, for any reason, power supply goes down, the valve closes immediately (intrinsic safe).
Suitable for cycle operation and qualified for continuous service (100% ED).
Equipped with max. flow rate and start flow rate adjustment.
An incorporated fine mesh filter protects the valve seat and disc as well as downstream components and prevents dirty contamination.
Provided with G1/4 pressure gauge on two sides in the inlet chamber, to connect manometers, pressure switches, leakage tester or other gas 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 f/f ISO 7-1 from Rp1/2 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

Voltage tolerance: -15% ... +10%

Power consumption see charts

Ambient temperature: -15°C ... +60°C

Max. operating pressure: 200 mbar (20 kPa) 360 mbar (36 kPa) 500 mbar (50 kPa)

Flow capacity see charts

Closing time: < 1 second

Opening time: Adjustable

Filter (except brass models): 600 μm

Protection class: IP54 (EN 60529) (optional IP65 with cable)

Cable gland M20x1,5 (EN 50262) for terminal box PG 9 for standard plug

Wires cross-section 2,5 mm2 max.

Electrical safety Class I (EN 60335-1)

Coil winding insulation Class H (200°C)

Coil thermal resistance Class F (155°C)

Materials in contact with gas Aluminium alloy:

Brass

Stainless steel

Plated steel

Anaerobic adhesive

Nitrile rubber (NBR)

Fluoro elastomer (FPM)

Polytetrafluoroethylene (PTFE)

The VML type valve is a safety shutting device using auxiliary power supply.

When it is de-energized, the spring pushes on the seal disc, keeping the gas passage closed.Now, the inlet chamber is under the gas line pressure, and it forces on the disc too, improving the seal.

When the coil is powered the valve opens slowly because of the hydraulic brake, against the strength of the spring and gas pressure. The rapid stroke may be adjusted using the regulating screw on the top (see the installation and service instructions), to adjust the initial gas flow. Main flow and opening time can be adjusted also.

If the power supply is shut off, the valve rapidly closes, interrupting the gas flow