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Pneumatic Accessories
气动附件
JACK FANG 星域控制机电设备(上海)有限公司

Pneumatic Accessories

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Filter Regulators过滤减压阀 Pneumatic Booster增容器 Quick Release Valves快速泄放阀 Solenoid Valves电磁阀

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Fisher 377 Trip Valves气路控制阀

Role of Filter Regulator
Actuator Loading Pressure 0 To 18 psig Current-to-Pressure Transducer Control Signal Electronic Controller

I/P

4 To-20 mA dc Filter Regulator Plant Air 80 To 100 psig typical

Supply Pressure 23 psig typical

Process Variable Transmitter
regpid

Figure 17-1. Filter-Regulator Application

Function:A filter regulator removes dust, dirt, pipeline scale, and other impurities from an air supply , and it reduce the pressure of the supply
过滤减压阀过滤气源里的灰尘,污垢等杂质,并减小供气压力

Regulator Operation

Figure 17-2. Direct-Operated Regulator

Major elements: A measuring element or diaphragm, a Spring and a valve.
主要元件:测量元件/膜片,弹簧,阀体

Typically Regulator
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Standard Application
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67CFR 64 95H
?A separate

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High Capacity
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external filter is also often used

经常会使用一个单独提供的过滤器

Booster Function

Figure. Pneumatic Booster Function

Function:Accept a pneumatic input pressure and a supply pressure, and they provide a pneumatic output pressure that is proportional to, but independent from, the input pressure.

Booster Operation
Input Pressure

1/4 “NPT
Upper Diaphragm

Exhaust

Diaphragm Spacer

Exhaust Valve Supply Pressure

Lower Diaphragm Output Pressure

3/4“NP
T
Supply Valve

T Figure 17-6. Typical Booster Design

booster1

3/4“NP

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从减压阀输入气源压力(Supply),信号接口端 输入信号压力(Iuput Signal),那么如下图上方膜片 ③受到压力,使膜片组合件向下移动,同时阀芯⑦ 也会向下移动,这时输入压力通过阀芯底座通路流 入到输出接口(Output)并输入到执行机构。当输出 压力增加到信号压力相同时,阀芯⑦重新上升,最 终信号压力和输出压力保持相同。相反,输出压力 大于信号压力,则膜片组合件向上移动,输出压力 会通过阀芯上方空隙向排气环④排气。根据信号压 力而变化的输出压力的灵敏度可以通过调节螺丝① 进行调解,通过调节可以改善系统的稳定性。

Booster Operation

Booster Typical Installations

Repeater, Reducers, Boosters

Figure. Pressure Repeaters, Pressure Reducers, and Pressure Boosters

1:1 Repeater: Produce an output press that is identical to the input press. Pressure Reducers- Produces an output press that is less than the input press. Pressure Booster:Produces an output press that greater than the input press.

Diaphragm Relative Areas
Upper Diaphragm Is Larger Than the Lower Diaphragm Input Upper Diaphragm Is Smaller Than the Lower Diaphragm

Exhaust

Output Supply

Lower Diaphragm Pressure Booster
reduceboost

Pressure Reducer

Figure 17-8.

Diaphragm Area Relationships; Booster and Reducer

Dead band Volume Boosters
Input Dead Band Adjustment (Needle Valve) Exhaust Bypass Output Supply Large Valves

volumeboost

Figure 17-9. Deadband Volume Booster

1: 1 volume booster that include a bypass valve. Direct the normal control signal to the downstream device unless a large or sudden change occurs in the control signal.

Volume Boosters Capacities

Figure. Capacities of Volume Booster 2625

Volume Boosters Application
Supply Pressure Volume Booster Guidelines Vent 1. Select Boosters Only When P/P Necessary To Prevent Damage And Ensure Safety 2. Connect The Booster Output To Large Volume Devices 3. Install A Booster In Combination With A Positioner To Preserve Good Control

Volume Booster Positioner Output Control Signal Supply Pressure Positioner

P

vbguide

Figure 17-11. Volume Booster Application Guidelines

Quick Release Exhaust Valve
Quick Release Valve

Supply Pressure Instrument Input Signal Exhaust (Limited Capacity) View A Limited Capacity Exhaust Through The Loading Pressure Instrument
qrvsinst

Exhaust (High Capacity) Supply Pressure Instrument Input Signal

View B High Capacity Exhaust Through A Quick Release Valve

Exhaust Cv through the instrument is relative small. Using quick exhaust valve which is mounted just upstream of the actuator loading pressure connection

Relative Exhaust Capacity-Various Devices

Instrument Fisher Type 546 I/P Transducer Fisher Type 3582 Positioner Moore Type 61H Volume Booster Fisher Type 2625 Volume Booster (1/2 inch port) Rexroth Quick Release Valve - 3/8 inch port Rexroth Quick Release Valve - 1/2 inch port Rexroth Quick Release Valve - 3/4 inch port Rexroth Quick Release Valve - 1 inch port

Exhaust Cv 0.36 0.19 1.02 3.32 3.08 5.5 10.55 13.45

Figure 17-12. Installation And Relative Cv Ratings Of Quick Release Valves

Quick Release Valve Operation
Diaphragm Outlet Port (To Actuator) Inlet Outlet Port (From Port Loading Instrument)

Inlet Port

Exhaust Port

Annular Area That Is Connected To The Output Port

Exhaust To Atmosphere

Filling
rexroth

Exhausting
View B

View A

Figure 17-13. Operation Of A Quick Release Valve

Quick Release Valve Application
Quick Release Valve Loading Pressure Exhaust

Diaphragm Pressure

Diaphragm Pressure Spring Pushes Up Spring Pushes Down

Quick Release Valve Loading Pressure Exhaust

Direct-Acting Actuator Quick Release Valve Shortens The Stroking Time For Opening The Valve
qrelact

Reverse-Acting Actuator Quick Release Valve Shortens The Stroking Time For Closing The Valve

Figure 17-14. Impact Of Quick Release Valves On The Stroking Time Of Direct And Reverse-Acting Actuators

Needle Valve Adjustment
Needle Valve Bypass

Quick Release Valve Loading Pressure

Input Signal Supply Pressure Positioner
qrelndl

Figure 17- 17-15. Needle Valve And Bypass For Adjusting The Exhaust Time

Solenoid Valves

Spring Valve Spool Port A Port A

Spring Valve Spool

Port B

Common Port

Port B

Common Port Coil

Coil

A6497

De-Energized

Energiz ed

Figure 17-16. Typical 3-Way Solenoid Valve

Solenoid valves are small, on-off valves that activated by energizing an electrical solenoid.

Solenoid Valves

Solenoid Valves

Solenoid Valves

Solenoid Valves

Solenoid Valves

Solenoid Valves

Solenoid Valves

Solenoid Valves

Solenoid Valves

Initiating the Inherent Fail Mode
3-Way Solenoid Valve S Casing Pressure Flow When De-Energized I/P Flow When Energized

S

S

Vent

4 to 20 mA Control Signal

Regulated Supply Pressure
solinh

Figure 17. Initiating The Inherent Actuator Fail Mode With A Solenoid Valve

Forcing the Fail Mode Opposite Normal
3-Way Solenoid Valve S Casing Pressure Flow When De-Energized Flow When Energized S S

I/P 4 to 20 mA Control Signal

Regulated Supply Pressure
solopinh

Figure 18. Forcing The Fail Mode That Is Opposite The Inherent Fail Mode

Initiating LILP
3-Way Solenoid Valve Casing Pressure S Flow When De-Energized Flow When Energized

S

S

Plugged Port I/P

4 to 20 mA Control Signal

Regulated Supply Pressure
sollilp

Figure 19. Initiating The LILP Fail Mode With A Solenoid Valve

Type 377 Trip Valve Operation
Trip Pressure Adjustment Spring Exhaust Valve (Closed) Upper Diaphragm Supply Diaphragm (Down) Port D Port E Valve Spool (Up Position) Supply Vent Port A Port B Lower Diaphragm Port D (Closed) Port E Exhaust Valve (Open) Exhaust Valve Spool (Down Position) Vent Port A (Closed) Port B

Main Valves (Closed) Port F Port C Port F Port C

Main Valves (Open)

377op

View A Supply Pressure Greater Than Trip Pressure

View B Supply Pressure Less Than Trip Pressure

Figure 17-20. Trip Valve Operation

Normal Operation
Supply Pressure to Charge Volume Tank Lower Cylinder Pressure Upper Cylinder Pressure Positioner

Upper Cylinder Supply Pressure A Lower Cylinder Check Valve

D E

B

F

C Volume Tank

377norm

Figure 17-21. Trip Valve During Normal Operation

377-Fail Down Configuration
Positioner

Upper Cylinder Supply Pressure Lower Cylinder Check Valve

D E

A

B

F

C

Loading Pressure

377d

Exhaust

Volume Tank

Figure 17-22. Trip Valve Connections to Provide a Fail-Down Action

377-Fail Up Configuration
Positioner Upper Cylinder

Supply Pressure A

Lower Cylinder Check Valve

D E

B

Exhaust Loading Pressure Volume Tank

F

C

377u

Figure 17-23. Trip Valve Connections to Provide a Fail-Up Action

377-LILP
Positioner

Upper Cylinder Supply Pressure A Lower Cylinder

D E

B Cylinder Pressure Trapped F Plugs C

377l

Figure 17-24. Trip Valve Connections for Lock-in-Last Position Action

Sample


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