Automation electric valve

No pipeline system is unthinkable without the use of such a regulatory body such as valve.This type of valves used for fluid flow overlap, vapor or gas through the pipe.

All valves are 3 types: conical, klinketnye and ring.Most practical application received klinketnye valves, which overlap the liquid flow in a pipe with a flat shutter included in the liquid stream perpendicular to the flow.

Understanding Automation electric valve

have any gate, there are two functions: opening and closing of the pipeline.Team it performed in the course of changing any of the monitored parameters: pressure, temperature, flow rate.If the valve is included in a complex control system, for opening or closing command can be supplied depending on the condition of pumps and fans.

To valve remote control use different types of actuators: hydraulic, pneumatic, electric.In order to use the automatic control of the actuator, as it is most convenient and efficient.The induction motor is often the electric drive for valve.Its output shaft connected to the worm gear, the output gear which engages with the screw at the outlet valve.

In operation, the motor current is shut off liquid valve with a screw falls or rises, carrying the closing or opening of the valve.Gear output gear through the intermediate gear transmits the rotation multiple disks with special cams.At the time of opening the valve, these cams are rotated to the right side and switch electrical contacts KVO switch.At the time of the closing of the valve opposite the cams rotate to the left side and close the circuit breaker contacts KHP.All wheels with cams installed in such a way that the full opening of the valve is activated switch quo and the complete closure - LSC switch.

The electrical power control circuitry valves involves 3 control modes: automatic, remote control and adjustment.

Remote mode is used in the management of power at a distance, for example, a control room.For the translation of automation in this mode 1PU control switch set to "Remote" switch 1VB to "off" switch 2VB to "enabled".Power to the control room control is supplied through switch B.

scheme functioning in electric

remotely To implement the command "open valve", you must click 1KU.In this case, the inclusion of 1RP will relay that closes its open contact in the power supply circuit of the coil starter software.The actuator is switched on and initiates the start of the motor which opens the valve and through the mechanism described above.

scheme Upon reaching the valve end position, immediately going on, pressing the limit switch CWE.At the same time it closed contact opens and produces KVO1 off starter software.This triggers off valve motor.At the same time KVO2 open contact closes and makes the inclusion of LO light bulb, which indicates that the valve is currently open.

Similarly to the scenario happening reverse command "close valve" in using already 2KU button.In this case, after the complete closure of the valve lamp lights LZ.

To operate the alarm circuit is used the principle of formation of polar signals.It consists in that the semiconductor diodes are sensitive to the direction of flow of electric current.This allows you to make all the equipment sensitive to this parameter.To ensure that a particular direction on the control panel and power on the object mounted on the two semiconductor diode.They produce half-wave rectification and full The election.This ensures that a single wire 2 signals.When fully open the valve, leakage current through diodes 1D and 2D at a burning light bulb LO.When the valve is fully closed, current flows through the diode 3D and 4D with a burning lamp LZ.

features Automatic mode

difference between automatic drive control mode, the valve is in the absence of any operator involvement.Automation is achieved by setting the valve actuator 1PU switch is set to "Automatic".In this case the VC switch must be in position "on", 1VB switch in position "off" and switch 2VB able to "on".

sensors that check values ​​of parameters such as flow rate or gas temperature level or pressure, give a signal when it reaches a predetermined level in the control scheme where there is a contact closure 1RK or 2RK.This causes the relay included 1RP or 2p.In turn, software or magnetic actuators PZ execute commands to open or close the valve, respectively.Control command execution is carried out by the presence of one of the tanning bulbs LO and LZ.

Features commissioning mode

adjustment mode is required for the validation work with electric gate after the initial installation or repair.To install the system in this mode you need to switch the switch 1VB in position "on".Power is sent to the control circuit turning on the switch AB.To execute the command "open valve", you press the button 4KU.This action ensures the supply of power to the magnetic contactor open on the valve.

When a switch ON, the scheme following changes occur:

1. Contact PA1 in samoblokirovochnoy circuit closes and there is command memorization.
2. Contact PA2 in the interlock circuit is opened to avoid filing false commands.
3. Closes motor circuit through 3 power contacts and PA3 is its inclusion, the valve moves upward.

At the time of the full opening of the valve cam disc by pressing the switch CWE.Its closed contact opens, including starter software.In this case the contacts return to their initial state and the motor is stopped, the valve is stopped.

To perform the reverse command "close valve", you press the button 5ku, which supplies power to the magnetic contactor closing valves PP.Similarly, the team described above is carried off the electric supply circuit.This changes the direction of rotation of the rotor (reverse mode).Thus, there is a complete closure of the valve.Turning off the electric motor takes place after the opening of the switch contact KHP.

Forms control circuit protection

Like any complex electromechanical devices, automatic valve control circuit has several types of protection against all kinds of loads.

control panel The control panel has a safety relay button that serves to instantaneous emergency stop of the motor.At the same time, there are automatic security features:

1. Protection against undervoltage, also known as zero protection.Its operation takes place in a moment of complete power failure in the network or its critical decrease.The goal - to eliminate the ability to self-start the motor when a sudden voltage recovery.This protection is carried out by means of magnetic and electromagnetic starters voltage relay.
2. Electric self-locking.This type of protection is achieved by turning the NC contact to the starter software in the power supply circuit starter PP and back.That is, until the starter ON is ON, the starter feed circuit PP is uniquely open and force a CT contactor with magnetic actuator software under any circumstances can not be.
3. protection of the electric motor from overloading during emergency valve jamming is done by opening the contacts of the final moment of the clutch switch VM, which is incorporated into the overall supply chain of both induction coils starters.
4. Maximum protection ensures complete safety of the motor in the event of a short-term overload and short circuit.It is carried out through the use of electromagnetic fuses or circuit breakers.

motor protection using PKP1

device To protect the valve actuator at the pumping stations are often installed special device PKP1:

• PKP1T - controls the current valve position on the current consumed by the electric drive, and the time of its movement.
• PKP1I - controls the current valve position by measuring the pulse periods, coming from the sensor.It is located on the valve shaft.This takes into account the number of revolutions.

PKP1 The device is essential for the control gates and valves in large pumping stations and the city "Vodokanal" system, and to ensure the protection of their mechanisms and drives in case of sudden jamming without limit switches.

main protective functions of the instrument:

• Automatic shut-off when the electric valve end position without using limit switches.
• Implementation of the display and control of the current position of valves in%.
• Emergency stop control and alarm "Alarm" at the time of sliding the drive mechanisms or wedge gate valves.
• PKP1 has two output relays, control valve, two relays to simulate the operation of the limit switches and relays for an alarm.

addition, if desired the consumer can be set PKP1 interaction interface module with RS-485 or a computer module, which creates a uniform current signal (4-20 mA) which is proportional to the degree of opening of the valve flap.

To configure this device directly on the site, with the help of the drawing set timing valve movement and options to determine its final position.

If we know the operating current of the motor, you should just set the parameters of safety shut-down.These settings will be stored for a long time in the non-volatile memory and remain unchanged even if power is turned off.Programming the unit is carried out buttons, which are located on the front panel.To prevent unauthorized access to change the default settings, there is a special protection.

Automation electric valve can be used not only in large industrial enterprises and urban water supply networks, but also in large-area households.This system will ensure quality control of various parameters in the heating system or water supply.If your site has several buildings, united by a common water supply network, the automation will not hurt you.