VMM Model Elektrogas Multiple Safety Solenoid Valve For Gas Regulating Trains

Elektrogas VMM type valve is a combination of two valves in an only compact and versatile valve housing. The first valve is a fast opening safety solenoid valve. The second valve may be a fast opening or a slow opening solenoid valve to adjust the gas flow, with a first adjustable fast stroke and a second adjustable slow stroke. It is possible connect a third by-pass / pilot valve, which performs by driver stage or to obtain a second fast (slow) stroke or both. This type of device is suitable for gas and air blocking and adjusting controls in atmospheric burners or fan-assisted burners (with one or two stage operation), in industrial kilns and in all gas equipments which use regulating trains.

Specification

The VMM type valve is a combination of two solenoid valves in an only compact and versatilevalve housing.

This type of device is suitable for air or gas blocking and releasing controls (with one or twostages operation), required in gas power burners, atmospheric gas boiler, industrial kilns andothers gas consuming appliances.

Technical Specifications

Description

The valves are made of aluminum alloy die-cast, with a range for inlet/outlet connections fromDN20 (3/4") up to DN80 (3").

Sealings are made of NBR-based rubber certified for use with gas (EN 549).

Pipe connections meet group 2 and backpressure sealing is compliant with class A, accordingto EN161 requirements.

A third valve with capacity of DN15 or DN25 can be fitted to by-pass the second one and have alow fire stage or a second outlet for pilot bumer (pilot execution).

Suitable for use with air and non-aggressive gases included in the 1, 2 and 3 families (EN 437).Special versions for aggressive gases .

The whole range can be provided in Ex-proof execution, for use in Zones 2 and 22, according to2014/34/EU Directive (ATEX).

The valve is open only when energized: if, for any reason, power supply goes down, the valvecloses immediately (intrinsic safe).

Suitable for heavy-duty cycle operation and qualified for continuous service (100% ED).

Equipped with flow rate adjustment.

An incorporated fine mesh filter protects the valve seat and disc as well as downstreamcomponents and prevents dirty contamination.

Provided with bilateral pressure ports on two sides in all pressure chambers, to connectmanometers, pressure switches, leakage tester or other gas equipments.

The coils are provided with terminal box or with ISO 4400 plug. Both systems are provided withsuitable cable gland to avoid water and dirty contamination.

The normally open vent valve VMRNA can be integrated in VMM from 1"V4 to 3"; dimensionsand piping are the same of third pilot valve. See VMRNA datasheet for other details.

All components are designed to withstand any mechanical, chemical and thermal conditionoccurring during typical service. Effective impregnation and surface treatments have been usedto improve mechanical sturdiness, sealing and resistance to corrosion of the components.

Valves are 100% tested by computerized testing machineries and are fully warranted.

Function and Application

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

The first valve (A) is a fast opening safety solenoid valve. When it is de-energized, the springpushes on the seal disc, keeping the gas passage closed. Now, the inlet chamber is under thegas line pressure, and it forces on the disc too, improving the seal.

When the coil is powered the valve opens rapidly, against the strength of the spring and gaspressure.

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

Equally, the second valve (B) may be a fast opening or a slow opening solenoid valve to adjustthe gas flow, with a first adjustable fast stroke and a second adjustable slow stroke.

It is possible to connect a third by-pass valve (C), which works as low fire stage or to obtain asecond fast (slow) stroke or both.