Electric sleeve control valve

Electric sleeve control valve, the valve core structure is the sleeve and the valve for the gap with the sleeve to open a number of throttle windows, the shape of the window determines the flow characteristics of the valve, the size of the window affect the control valve Flow coefficient Cv. Seat with self-aligning without thread-type structure, the valve seat on the cone sealing surface and the valve on the cone to form a sealing surface seal to ensure that the valve flap in the valve seat when the valve close off. The size of the seat diameter affects the flow coefficient of the control valve Cv. The valve is parallel to the axis of symmetrical distribution of the balance hole, so that the upper and lower valve surface of the chamber connected to the valve, so that the role of the valve medium in the valve axial force most of the offset each other, the media produced on the stem Balance is very small. By receiving the signal of the industrial automation control system (eg 4 ~ 20mA or 1-5V DC) to drive the valve to change the cross-sectional area between the spool and the valve seat to control the flow of the pipe medium, temperature, pressure and other process parameters. To achieve automatic adjustment function.

1, installation and use

Regulating valve installation does not meet the requirements of the failure will cause a huge waste, on the contrary, the installation properly, to ensure normal start and extend the service life. Reduce maintenance workload and achieve good system control performance.

(1) the installation of control valve in general should consider the following aspects:

① safety: the installation process of personnel and equipment security.

② control performance: piping system pressure loss should be calculated when the size of the valve to consider the same pressure to ensure that the required flow characteristics. Import and export should try to ensure adequate straight pipe.

③ installation location: there should be enough space for the operator to manually operate (including bypass operation) and to ensure that the control valve and accessories on the spot removal and maintenance of the possibility.

④ control valve group: generally in the process piping are installed shut-off valve bypass valve and control valve into a valve group to meet the needs of continuous operation of equipment. Check the valve with a shut-off valve. Adjust with bypass valve.

2) Field installation

Installers should first realize that the control valve is a sophisticated equipment, are not allowed to crash fall, so as not to damage. Specific attention to the following:

① valve is best vertical vertical installation on the pipeline. Valve weight and vibration occasions should be added support frame.

② the valve body to avoid the front and rear piping or reconcile the flange of a serious different shaft and subject to excessive stress.

③ in the initial start and after the shutdown should be washed after the first piping system installed valve. Or in the valve before the installation of transition filter.

④ Install the control valve according to the arrow in the direction of flow on the valve body.

3, maintenance and repair

(1) maintenance

① often check the pipeline there is no rust, welding slag, dirt, dust disabilities.

② should always check the support, large weight and vibration occasions supporting the frame.

③ power must not be faulty.

④ valve body and the upper valve cover to use a long time to replace the gasket, to be replaced in time to replace the only need to remove the upper cover to place a new gasket.

⑤ If there is leakage to fill the packing material to replace the sealed packing, replace the stem when the replacement, pressure plate and packing gland removed, you can load a new filler.

⑥ regular maintenance.

⑦ long-term parking, should be attached to the flange of the protective cover, so the interface should be blocked with plastic plug. At the time of parking, ensure the overall vertical or horizontal position of the valve,

⑧ Do not support the valve in the sensitive parts, such as valve positioner, joints, wiring, etc..

(2) maintenance

When the control valve in use can not meet the operational requirements, or after a long period of operation in order to prevent accidents and regular inspection, it must seriously repair it. Maintenance work usually has the following main contents:

① Valve cleaning - overhaul the valve removed from the process piping, it must be all the above process medium impregnated parts clean. So that some corrosive or other damage to the role of fluid on people and equipment damage. At the same time should be removed parts exposed surface corrosion.

(2) Removal of the valve - In order to check all the parts to determine the range of repair and replacement. First, the actuator and valve should be completely removed. The demolition must be protected after precision machining such as spool, seat, stem, putter, sleeve and other parts and all parts of the precision machining surface to prevent damage to the minimum cost of repair, dismantling the seat should use special tools The

③ Main parts of the repair - spool throttling surface and the valve seat and the sealing surface of the valve if there is a small rust and wear. Can still use the general mechanical processing and grinding methods to repair. If the damage is serious, you must replace the new parts. Repair required to ensure that the spool and valve seat coaxial.

Damage to the sealing surface of the stem can only be replaced with new parts.

Push guide and damage to the sealing surface. The reaction operator must replace the new parts. And for the role of the implementing agencies can still be properly repaired.

Compression spring in the maintenance, such as the impact of cracks and other effects of defects. You must use the new replacement.

④ replacement of wearing parts - the damage of the valve is mainly: packing, O-ring, gaskets, diaphragms and other parts.

Each time the repair of the packing, O-ring, gasket will replace the new pieces, the diaphragm is removed after the need to check whether there is any possible signs of cracking, aging and wear traces, and then depending on the specific circumstances decided to replace and no. Generally up to 2 to 3 years must be replaced.

⑤ into the equipment and commissioning - into the equipment in the parts of the positioning site, guide parts, threaded connection parts should be coated with appropriate grease, in order to facilitate the next maintenance demolition. But also pay special attention to the machine in the putter, spool parts and valve seat coaxial problem.

After installation and commissioning, must be through the standard products specified in the factory test project after passing the test can continue to install and use.