Contemporary installation of valves, in most cases, is carried out using elektrozadvizhki for pipelines. Especially in water piping systems, oil and gas. This is due to the fact that mechanical valves in modern conditions have become obsolete. And the ability to block the flow through the pipeline remotely, much more convenient, more economical and faster than a direct overlap of the valve. This makes it possible to build complex automated flow control system of a fluid in different directions or the water industry.
The principle of operation elektrozadvizhki
In the embodiment, there are several types of valves:
- Vee. Flat plug prevents flow perpendicular, as if to drive a wedge.
- Rotary. The damper is located in the tube itself and it overlaps the flow turning.
- Parallel. Are divided into one- or two-ring. The flow is blocked after lowering the drives in special grooves.
- Hose. The shutter is carried by strong compression hose.
In most cases, the actuator is used pursuant to the wedge bolts
That of mechanical valves to make the valve with electric drive, enough to an existing design to add asynchronous motor and worm gear. Rotation of the shaft is transmitted to the reduction gear, which drives the valve.
The use of electric drive allows you to remotely manage the process of unlocking / locking plugs that has been widely used in many fields.
Depending on the system parameters on the final design choice elektrozadvizhki will affect the following factors:
- flow medium aggressiveness
- operating pressure in the system
- environmental conditions
- necessary protection and security.
Elektrozadvizhka always duplicated in mechanical performance to the case of a power failure. To switch to manual operation at the site of the pipeline and valve arrangement endure controls switching to manual operation.
Elektrozadvizhki block diagram of the device shown in Fig. 3.
Actuators equipped with a limit switch through which the valve position register and receives signals reaches it end position control system. a torque limiting clutch allows protect the pipeline from damage due to jamming valve or contact with foreign objects overlap place, prevents damage to the entire system.
Electrical connection diagram elektrozadvizhki generally without pressure sensors or complex control systems of electric drive control system is as follows:
In this scheme, the signals from the limit switches stop the engine, and the valve is in either state "open" or "closed".
Materials manufacturing elektrozadvizhek
Valves made of the following metals:
- Brass
- Bronze
- Steel
- Cast iron
The most widely used execution of steel from pig iron as the most reliable in long enough to serve capable flawlessly, which is the main criterion for selection. Versions of bronze and brass are often used in specific pipeline systems where value selection valves producing material is important.
What is the advantage of using elektrozadvizhek?
The obvious advantage is the ability to use elektrozadvizhek remote control system, it has spread especially on the fire line. In it is not only the concept of opening and closing of flows, but also the registration of emergency situations and prevention of emergency situations. Cost elektrozadvizhki though higher than the standard mechanical, but the resulting benefits quickly pays all costs in the operation.
Also provides other advantages:
- the possibility of installation of pipelines in remote places, where there is no need to constantly control the system directly on the pipeline.
- rapid response to the current situation.
- significantly faster unlocking / locking of large diameter pipes, compared with the manual valves.
- possibility of constructing a complex piping systems, including automatic unattended.
Classification gate valves with electric drive.
With the proliferation of the use of valves in the early 19th century, it has developed and adopted a table of figures valves. It was established a set of rules to make it easier and convenient reading and identification of various designs of valves. Since the valve - this is just one of the types of valves makes sense to specify how it will look marking valves with electric drive, on 30s941nzh example.
"30" - represents a direct type valves, namely valve.
"C" - refers to a material of the shell of constipation, in this case carbon steel.
"9" - the type of actuator, in this case the electromotor.
"41" - refers to the product number in the factory.
"NJ" - the seal material is stainless steel.
The remaining types of markings are shown in Fig. 6.
Another important parameter in the selection valve is a DN (or control). DN adopted modern standard notation and conditional. Control (diameter conditional) formerly known gradually coming out of turn. Nominal bore denotes the inner diameter of the tube expressed in millimeters. For example, DN50 (or DN50) denotes a pipe having an inner diameter of 50 mm. Contingent size is called not by chance, because in the manufacture of pipes to withstand the exact dimensions of the inner diameter of not It makes economic sense, so it can vary within a small range, but consider this amount exact it is impossible.
Equally important is the parameter PN (or RC) indicating the pressure limit at which the normal operation of the device is provided. For example, PN15 indicates that the product guarantees operation at a system pressure of 15 bar.
Accordingly, depending on the performance of the valve and the pipe diameter in which it will be used to carry out selection of this type of actuator to the gate valve. The difference in using the drive pipe with DN50 and DN600 obvious, therefore the same type of valve actuator may be selected different.
From domestic manufacturers drives the most common are the product factories of "ZEiM" and JSC "Tulaelectroprivod". The most widely used engines series FEM-A11 are used for the most common pipe sizes from DN50 to DN150.
Types elektrozadvizhek and control systems
For electrical control systems there are several types:
- Multi. Elekrozadvizhki able to lock not only the flow in two positions open / closed, and with the possibility of flow control in several intermediate positions.
- Explosion-proof. System with reinforced construction in the event of emergency situations. They are mainly used in explosive liquids systems. Basically Petroleum, Chemical and Gas Industry.
- Integrated. Latches, equipped control system flow state sensors. Capable of automatically changing the position of the gate valve, depending on the current situation in the fixture.
installation and adjustment rules
Before you install the valve is absolutely necessary to make sure it is working correctly. To this end, a wedge is necessary to apply grease on silicone basis, if it is not, then shed plain water. Then you need to hold it to a state of closure and return to the open state until it stops. Making sure that the check valve operation is successful on a full cycle in manual mode and when the drive is running. Make sure that the pipeline for foreign objects and proceed to its installation. If it turns out that the flap does not work after installation it will lead not only to economic, but also moral inconveniences.
Also, before installation, make sure that the product is right for you in all respects, if a control is hard to go wrong, it's the value of PN sure to check. This setting should always match the operating conditions.
Fastening bolt for mating flanges must be of a certain diameter bolts, depending on the control is changed. Their values are given in the table below.
The number of fixtures and their locations bolts flange holes must comply with GOST 12821. Next, install the electric drive and made the final installation and installation of control systems.
Durability and recommendations for use
The warranty period of standard valves is 2 years service life - 10 years. Average yield at least 2500 cycles. When the right value is selected PN and careful use of the product without the emergency device can last much longer regularly. It is not recommended to service the product does not staff training to work, set up and operate the valves. If the system can prohibitive pressure value, set it supports or compensators.
You can not use the valve as a support for the pipeline, it greatly reduces the service life of the device. It is forbidden to change the packing or to carry it to the pad.
