In industrial automation appearance, control valve is ponderosity, together with structure is simple, often be not taken seriously by people. But, it goes up in craft conduit, working requirement is complex, once appear problem, everybody busy hand busy foot. Because its are cumbersome, the problem searchs hard accurate, often do not please painfully, still involve a system to join carry, system complete, adjust pollution of character, environment.
1, control valve often gets stuck or jam
Prevent (card) the method is here!
1) clean a law
The solder broken bits in pipeline, ferruginous, broken bits child wait to build a balance in next reduce expenditure mouth, oriented place, a powerful person cause inside aperture jam or get stuck to make generation of curved surface of core of a powerful person, spigot surface pulls impress of the generation on injury and nick, sealing surface to wait. Carry initial stage is cast after this often happens at casting transport system and overhaul newly. This is the commonnest breakdown. Meet this condition, must discharge leaves undertake cleaning, get rid of broken bits content, if sealing surface is returned by injury,answer abrade; the ground at the same time a place of strategic importance is opened, from the balance with rushing aperture drops the broken bits matter inside lid laying a powerful person, undertake rinsing to pipeline. Before joining movement, let control valve a standard-sized sheet, flow brings into medium to move normally again after period of time.
2) outside receive erode law
When using average a powerful person to adjust to a few easy precipitation, medium that contains solid grain, often jam in reduce expenditure mouth, oriented place, outside can issueing a place of strategic importance end lid of a powerful person to be in, receive erode gas and vapour. When when a powerful person generation jams or card lives, make the gas that above accepts or steam valve, can finish below the condition that does not change control valve rinse the job, make a powerful person moves normally.
3) installation provides filter way
To small-bore control valve, exceed little flow control valve especially, space of its reduce expenditure is especially little, there cannot be thing of little broken bits in medium. Encounter this circumstance to jam, a filter had better be installed on the conduit before a powerful person, in order to make sure medium is passed smoothly. Take the control valve that positioner uses, positioner job is abnormal, its enrage mouth of road reduce expenditure to jam is the commonnest breakdown. Accordingly, when taking positioner to work, must treat cause of good energy of life, the method that uses normally is on cop of source of the gas before positioner installation air filters pressure-relief valve.
4) increase standard of reduce expenditure clearance
The solder broken bits that is eroded in the solid grain in be like medium or conduit and rubiginous content because cannot cross reduce expenditure mouth to cause,jam, get stuck to wait for breakdown, can convert the reduce expenditure with reduce expenditure big gap, reduce expenditure area is window, mouth kind core of a powerful person, sleeve, because of its reduce expenditure area is centered and not be circumferential those who distributing, breakdown is eliminated easily. If be a powerful person of sheet, two-seater but instead of core of a powerful person of force plunger entity " V " the core of a powerful person of form mouth, or change a powerful person of whole set canister to wait. For example some chemical plant has a powerful person of a two-seater to often get stuck, recommend convert after sleeve a powerful person, the problem gets settlement immediately.
5) medium erodes law
Use medium oneself erode energy, erode and take away the thing that jams easy precipitation, easily, raise a powerful person or family thereby prevent a function. Common method has:
① changes to flow shut model use;
② uses system of clipper-built a powerful person;
③ erodes park of reduce expenditure mouth the fiercest place, use this law to want to notice to increase reduce expenditure of material be able to bear or endure erosive ability.
6) doctrine of look of direct instead horn
Direct flow to pour S, shed a route complex, go up, dead band of antrum issueing a look is much, the precipitation that is medium provided a place. Horny form joins, medium is just as had shed 90 ℃ bend, erode performance is good, dead band is small, easy design becomes streamline entity. Accordingly, use direct control valve generation is slight horny entity a powerful person can change to use when jamming.
2, the means of settlement of the discharge outside control valve
1) raise sealed oil standard
A powerful person of sealed to was not being used grease, can consider to increase sealed grease to raise sealing of lever of a powerful person can.
2) raise filling standard
Be opposite to raise filling the sealed function of lever of a powerful person, can use the method that adds filling. It is to use normally double deck, multilayer mixture filling form, pure increase an amount, if add 3 5, the effect is not apparent.
3) change law of black lead filling
The 4 fluorine filling that a large number of use, because of its working temperature is in - 20 ～ + inside 200 ℃ limits, going up when temperature, floor level, when change is bigger, its sealing drops apparently, ageing is fast, life is brief. Flexible black lead filling can overcome these weakness and service life is long. Some plants are consequently entire filling of black lead of instead of 4 fluorine filling, after buying the control valve that answer newly even to also change among them 4 fluorine filling black lead filling, use. But a difference of filling of use black lead is big, first when some still produces creeping phenomenon, must consider this somewhat.
4) change flow direction, buy P2 carries a law in lever of a powerful person
When △ P bigger, p1 bigger when, sealed P1 compares sealed P2 difficulty apparently. Accordingly, can adopt the method that changes flow direction, instead P2 carries P1 in lever of a powerful person in lever of a powerful person, this is tall to pressure, pressing a powerful person or family with big difference is more effective. If ripple is in charge of,a powerful person should consider sealed P2 normally.
5) use lens to pay sealed way
To going up, those who leave a top is sealed, valve base and go up, those who leave put oneself in another's position of a powerful person is sealed. If be plane sealed, below high temperature high pressure, sealing is poor, the discharge outside causing, can convert lenticular mat is sealed, can get satisfactory result.
6) change sealed spacer
Up to now, major sealed spacer still uses asbestine board, below high temperature, sealed performance is poorer, life is brief also, the discharge outside causing. Encounter this kind of situation, can convert twine spacer, "O " form annulus, a lot of factories already were used now.
