Safety solenoid valves for air and gas slow opening and fast closing
The VML type valve is a safety valve that is normally closed, with a fast or slow opening and an adjustable rapid section for initial gas flow. When not in the working position the spring works on the disc keeping the gas passage closed.
When the coil is powered the valve opens rapidly in the first section of the flow, then slowly, with adjust-able speed. When power is switched off the valve rapidly shuts.
This type of device is suitable for gas and air blocking and adjusting controls in atmospheric burners or fan-assisted burners, in industrial kilns and in all gas equipment which uses gas solenoid valves (qualified for continuous service – 100% ED).
Function and Application
The VMR type valve is a safety shutting device using the 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 which forces on the disc, increasing the closing function and improving the seal.
When the coil is powered the valve opens rapidly, against the strength of the spring and gas pressure. The flow may be adjusted using the regulating screw on the top (see the installation and service instructions). If the power supply is shut off, the valve rapidly closes, interrupting the gas flow
|Connections||Internal threaded ISO 7-1 from Rp3/8 to Rp2½|
|ANSI-ASME B1.20 from 3/8” NPT to 2”½NPT|
|Flanged ISO 7005 PN16 from DN40 to DN80|
|ANSI-ASA-ASME B16.5 class 150 from 2” to 6”|
|Voltage ratings||230 VAC 50/60 Hz|
|120 VAC 50/60 Hz|
|110 VAC 50/60 Hz|
|Voltage tolerance||-15% to +10%|
|Temperature||-15°C to +60°C (+5°F to +140°F)|
|Max. operating pressure||200 mbar (3 psig)|
|360 mbar (5 psig)|
|500 mbar (7 psig)|
|6 bar * (90 psig)|
|Body test pressure||1 bar (15 psig)|
|9 bar * (130 psig)|
|Closing time||< 1 second|
|Gas strainer||600 µm (0.02 in), metal mesh (except 6 bar models)|
|Enclosure||IP54 (NEMA 3), optional IP65 with cable (NEMA 4)|
|Cable gland||M20x1,5 for terminal box|
|PG 9 for ISO plug|
|Wires cross-section||2,5 mm2 max. (AWG 12) for terminal board|
|1,5 mm2 max. (AWG 14) for ISO plug|
|Electrical safety||Class I (EN 60335-1)|
|Coil winding insulation||Class H (200°C, 392°F)|
|Coil thermal resistance||Class F (155°C, 311°F)|