Solenoid Valve Manual Reset and Override

Solenoid Valve Manual Reset

• There are certain occasions where safety requires that a valve can not be remotely operated by a control system without an extra human input directly at the valve. This is what known as manual reset.

• To make the valve to change from its rest state, the coil needs to be energized and the lever or knob to be pulled to the fully open position state.

• If the valve is energized without manual intervention it will not open.

• There are other forms of manual reset with different characteristics.

Manual Latching

Manual latching is where the solenoid valve is opened by hand and will not close until the solenoid coil is energized this is also known as electrical trip or release.

Automatic Latching

An automatic latching lever is almost the opposite of this. In that the valve is energized to change the state which releases the lever. The lever falls due to gravity and holds the valve in the open position irrespective of whether the coil is energized or not.

The lever required to be manually operated in order to return the valve to the closed reset position.

Solenoid Manual Override

Solenoid Manual Override is a method of opening a normally closed valve (power to open) without having power.

• This is a mechanical device that permits a person to operate the valve by either hand or screwdriver. This is useful in case of a power failure or to assist in machine or in system set-up or in test.

• Usually when a normally closed valve needs to open, you apply power and the coil energizes to open the valve. But if power fails, and you still need to open the valve, the manual override will allow you to open the valve mechanically.

• Manual override is a mandatory feature in cars/automobiles that enables the car driver or owner to open the car's door with or without electric power.

• Manual override is a mechanical device that permits the momentary opening, closing or locking manual opening of normally closed valves or closing of the normally open valves is available as a factory option. There are a number of processing situations in which it may be required to actuate a single solenoid valve in an array of the valve without disturbing the electrical sequencing or piping of these valves.

• The manual override option is built into the metal bodies of these solenoid valves and will not affect its normal operation process unless actuated in the case of power failure or similar circumstance.

• The manual override option adds only marginally to the cost of the valve by the solenoid valve suppliers.

Author: R.Jagan Mohan Rao

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