Product Description> Control Valve 1 2 3 4 5 6

VIII Flow Characteristic Chart（refer to chart 3）

IX Installation of Control Valve
1、Before control valve installed, pipeline system should be cleaned completely, filth and welding residue removed lest locking when the valve working.
2、Control valve should be installed upright to places near the ground or the floor. When elevation of the pipeline is larger than 2m, platform should be set up as possible to facilitate adjustment, examination and dismantlement. Before using or replacing filling, nut connecting upper flange and the valve should not be dismantled or loosened.
3、When installing control valve, the direction of the arrow on the valve should be in consistency with the medium.
4、If nominal diameter of the control valve is different from nominal diameter of the pipeline, reducing pipe section should be added between the two.
5、Installing the control valve, please leave enough space for dismantling executive facility to facilitate wiring, adjustment and check.
6、Connection of control valve and pipeline needs welding. Welding manner is to weld adapter welded on the valve to the pipeline, connection manner of flange is to weld the flange to the pipeline. And the welding needs multiple grinding, multiple procedures of welding and heat preservation.
7、Nut of valve cap is generally screwed down and adjusted well exworks. If leakage appears in course of trial run or formal run, one can screw down the nut more. But pay attention to two points. First：do screwing equally, adopt cross nut screwing down and time-after-time screwing of one nut. If do unequally, valve cap will be deflected, valve pole bent and distorted then influence normal opening of the valve. Secondly：screw down till there is no leakage. Do not overdo or you’ll decrease use life of the valve base.
8、Out-shaft thrust of executive framework has generally matched well while lectotype. If thrust failed, you can check whether control signal interfered or not, or whether restricted by positioner and whether valve pole bent and distorted or not.

X Maintenance of Control Valve
    When control valve fails to satisfy demands in course of use, or after long-term operation, or check to prevent accidents, one must maintenance the valve. Contents of maintenance are：
1、Screw down valve cap
After running, stopping and restarting, no matter other valve components are dismantled and maintained, valve cap nut should be screwed down and adjusted again.
2、Valve disassembly
    High-pressure valve, especially in maintenance of welding connected valve, executive framework should be disassembled from the valve and inner components taken out of the valve. If the valve body is intact and sealing part undamaged, the valve body is not necessary to be disassembled from the pipeline. And when disassembling inner components, one should protect precision processed workpiece, such as flap assembly, throttle assembly and valve base and so on to prevent damaging.
3、Valve cleaning
    Disassembled valve body should be removed of process remainders and rust cleanly.
4、Maintenance and replacement of main components parts
    If there is small damage on sealing surface of flap and valve base, it can be repaired by mechanical processing and grinding；If seriously damaged, it must be replaced. And in modification, flap and valve base should be kept at right alignment.
If sealing surface of throttle assembly and valve pole, you have no other choice but to update the part.
5、Replacement of wasting parts
    Wasting parts of control valve are mainly fillings and seal ring of valve cap and so on.
6、Maintenance of executive framework
    Maintenance of executive framework please conduct referring to product manuals of electric or pneumatic one respectively.
7、Installation and Testing
    When assembling the valve, moderate lubricant should be coated on component assisting part, guide part and screw part. And pay attention to keep handspike of executive framework, valve pole parts and valve base at right alignment.
    Assemblage finished, the valve should pass test of exworks experimental projects stipulated by the standard and then be used continually.

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