|
1、Selection of the control valve to assess in detail the contents of （115QUESTIONS ）
1.1 Implementing agencies
|
(1)
Driving Mode choice : electric, pneumatic, hydraulic decision?
|
(2)
Electric companies to choose the general type or electronic structure?
|
|
(3)
Electric body is rectangular or straight trip itinerary?
|
(4)
Kok itinerary Electric body is straight - or even crank-bar?
|
|
(5)
Electric signals in the selected agencies : -- II, III -- or the other? |
(6)
Explosion-proof electric implementing agencies or not?
|
|
(7)
Servo Amplifiers selected?
|
(8)
Need position feedback signals?
|
|
(9) 是否需要手操作？
|
(10)
Pneumatic institutions film with piston-type decisions?
|
|
(11)Pneumatic piston-enforcement agencies and the proportion of two-selected?
|
(12)
Pneumatic piston implementing agencies and angular straight trip itinerary decision？
|
|
(13)Pneumatic piston spring with implementing agencies and non-spring-selected？ |
(14)
Pneumatic Films implementation of a single spring in the old structure or multiple small spring structure.
|
|
(15)
Positive and negative effects of selected?
|
(16)
Spring selected areas (involved)?
|
|
(17)
Spring scope of the work selected (involved)?
|
(18)
Need longer stents?
|
|
(19)
Implementing agencies selected specifications (involved)?
|
(20)
Implementing agencies at the standard mix with the valve or reduced or increased?
|
|
(21)
Gas size of the signal decision？
|
(22)
Gas signal interface requirements？
|
|
(23)
Itinerary (angle) selected？
|
(24)
Size of gas decision？
|
|
(25)
Movement speed requirements？
|
(26)
Environmental conditions satisfied？
|
|
(27)
Restrictions on the size or shape ？
|
(28)
The weight limits or not？
|
|
(29) Color requirements？
|
|
1.2 Packed with top
|
(30)
Selected forms of the superstructure, the ordinary type, with Fin - type, long-necked type, bellows seal?
|
(31)
Temperature Valve election with Thermal unit structure above or the ordinary heating filler structure?
|
|
(32)
Cryogenic valve election Vatidae shelters or with endothermic unit plus hypothermia filler structure？
|
(33)
Superstructure oriented forms : normal type, add-balance -？
|
|
(34)
Tetrafluoroethylene graphite filler or filler？
|
(35)
Single - or multiple-seal sealing？
|
|
(36)
Fill the need for anti-loaded？
|
(37)
Bellows material selected？
|
|
(38)
Material from the site selected？
|
(39)
Lining and whether the lining material selected？
|
|
(40)
Oriented material from the selected sets？
|
(41)
Whether the guide sleeve wear alloy
|
|
(42)
Cover and seal the valve structure and the material selected？
|
|
1.3 Valve pieces
|
(43)
Spool, the valve seat leakage rating？
|
(44)
Seal : hard or sealed; Seal owed？
|
|
(45)
Need to wear alloy？
|
(46)
Soft seal structure with the type : hard right soft seal, soft on soft seal, "O" - shaped seals, flat seals？
|
|
(47) Soft Seal materials？
|
(48) Seat number？
|
|
(49) Seal number Spool？
|
(50)
Spool-oriented type : Top-oriented, with the lower part of the top-oriented, self-oriented？
|
|
(51)
Sleeves cut expenditure requirements window？
|
(52)
Spool window requirements？
|
|
(53)
Add to the need for guidance？
|
(54)
Oriented aspect is the need alloy wear？
|
|
(55)
Big pressure-balance valve structure considerations？
|
(56)
Seat material selected？
|
|
(57)
Spool material selected？
|
(58)
Valve material selected ？
|
|
(59)
Stem the need for increased？
|
(60)
“Ｏ”- Ring material selected？
|
|
(61)
Corrosion Resistance of consideration？
|
(62)
Tolerance of cavitation performance considerations？
|
|
(63)
Erosion-resistant properties of consideration？
|
(64)
Stopping performance?
|
|
(65)
Spool, and the diameter of the valve seat is consistent diameter or necking？
|
(66)
Flow coefficient values need calibration？
|
|
(67)
Seat leak test the special requirements？
|
(68)
Need special cleansing ？
|
|
(69) Whether spare parts？
|
|
1.4 Valve
|
(70)
Valve type selected (the first important Selection content)？
|
(71)
Diameter of the decision (the first important calculation.)？
|
|
(72)
Connectors : Threaded, flanged-welding -？
|
(73)
Valve seating decisions？
|
|
(74)
Flange pressure level and the standard of decision？
|
(75)
The flange from the requirements？
|
|
(76)
Close valve when the pressure of work Check (calculated as the second most important)？
|
(77)
Check adjustable R (content is calculated)？
|
|
(78)
Opening checking (is calculated.) ？
|
(79)
Medium temperature selected valve structure and materials
|
|
(80) Leakage of the request？
|
(81)
The flow characteristics of the selected？
|
|
(82) Flows selected？
|
(83)
Role : open air, gas closed selected ？
|
|
(84)
Need insulation jacket？
|
(85) The noise limit ？
|
|
(86)
Valve material selected (Selection of the second important element)？
|
(87)
Lining need? What lining material？
|
|
(88)
Corrosion on the full consideration？
|
(89)
Right temperature, pressure, sealed the reliability of the？
|
|
(90)
The value of the properties to consider than？
|
(91)
Wear the right to consider？
|
|
(92)
For the maintenance of the properties considered？
|
(93) Appearance of the request？
|
|
(94)
Installation of space limitations？
|
(95) Of the weight limits？
|
|
(96)
On the use of document requests？
|
(97) Packaging requirements？
|
|
(98) On the transport requirements？
|
(99)
Technical conditions of the special requirements (such as cleaning, decontamination oil ...)
|
1.5 Annex selected
|
(100)
The location selected？ |
(101)
Selected converters？ |
|
(102) Ex consideration？
|
(103)
Air filtration sold selected？
|
|
(104)
Bao-valve selected？ |
(105)
Following the selection of actuator？ |
|
(106)
Selected solenoid valve？ |
(107)
Switch selected itinerary？
|
|
(108)
Need feedback position signal devices？
|
(109)
Hand wheel agencies selected？
|
1.6 Whole Fault selected
|
(110)
Stolen gas valve position : Full closure to maintain？
|
(111)
Lost when power valve position : Full closure to maintain？
|
|
(112)
But the failure -- the missing gas valve position : Full closure to maintain？
|
(113)
Lost electricity, gas lost contradictory requirements of the position, the need for hand Wheel？
|
|
(114)
Failure to require emergency action, as a normal two-conditioned function of selected？
|
(115)
When the valve closed position and the pressure imbalance in the calculation and implementation of the selected？
|
2、Regulating Valve Selection simplified (tips)
Regulating Valve Selection is too complex to provide the following ideas to simplify the selection.
（1）Valve-choice
Regulating valve-best option is complete, light weight full-featured ultra-light control valve to replace other regulating valve products, simplified by the use of futures products and functional subset worried Selection misconduct (such as direct trip valve in the landscape category; cut off relations with the pressure) troubles.
（2） Implementing agencies the choice
Implementing agencies choice : choice of imports of electronic enforcement agency to overcome a series of unreliable; Film-enforcement agencies use precision small series; Piston enforcement agencies should consider the types of gear; tell pressure valve closed by the manufacturers implementing agencies selected size.
（3） The choice of materials
The issue is more complex. Because many corrosive media does not exist right Teflon corrosion, it should use all tetrafluoroethylene corrosion resistant valves, so that corrosion occasions Selection be greatly simplified, but when the temperature
>180 ℃ 、 < －４０ ℃、
PN≥2.5KPa
，Consider further support of corrosion-resistant alloy.
（4） Spring scope of choice
As for the implementation of the film valve is most occasions is worthy of positioning device that can fully utilize 250KPa natural gas resources, Selection of a medium stiffness, but also take into account higher output of spring 60~180KPa; Similarly, Pistons right choice 150~300KPa implementing agencies.
（5） Flow Characteristics of choice
① When the parameters get closed, the election of a few properties：
②
When the system was transferred to the fast response time, such as flow control, fluid pressure regulator, the Commission on several characteristics; When the system's slow response, Level system, temperature control system, the linear characteristics of the election；
③ Ｓ Relatively small, the election of a few properties； ④
Valve may be small opening work, the election of a few properties。
（6）
Flows choice
Sealing category of single straight trip to the control valve normally open-flow election; When asked to cut off and erosion prevention, Closed-election flow (flow closed-poor stability, should consider the stability of corresponding measures).
（7）
Packed choice
When the belt positioning device, used as far as possible wear and heat, long life, reliable graphite seal packing.
（8）
Positioning devices and the choice of converters
Translators in no position to improve output, and improved movement speed, precision location of the three, they are normally should use locator (positioning device with a considerable price converters).
（9） Electromagnetic valve option
The reliability of the solenoid valve to be placed in the most prominent position, and should use high reliability imports solenoid valve. Selected solenoid valve electricity, power outages and the main valve, and told production.
Details please Plant Technology, the Ministry of Contact ,
Tel
:0577-65021168/13758782848
|
