Air Operated Valve CalibrationNMV21

1

2

Terminal Objective

Given the necessary references, tools and test equipment, the technician will maintain pneumatic control valve components. Mastery will be demonstrated by completion of all Laboratory Practical Evaluations and scoring at least 80 % on an end of course exam.

3

Enabling Objectives

Given an example or illustration, identify the types of control valves.

Given an example or illustration, identify components associated with various valve types.

Identify flow characteristics of various valves .

Describe the operation of Pneumatic Actuators.

Describe the critical elements associated with valve packing.

Describe the operation of a flapper/nozzle detector.

Describe the operation of a booster relay.

4

Enabling Objectives

Describe the operation of air regulators.

Describe the operation of valve position indication devices.

Describe the use and operation of solenoid valves on air operated valves.

Calibrate a Fisher 546 I/P Converter.

Benchset diaphragm actuators.

Calibrate Valve Positioners.

Calibrate a Steam Bypass Control Valve.

5

Typical Globe Valves

FLOW

6

Typical Gate Valves

7

Typical Butterfly Valves

FLOW

8

Typical Check Valves

FLOW

FLOW

SPRING

9

Typical Diaphragm Valve

10

Typical Ball Valve

11

Typical Plug Valves

12

Typical Globe Valve ConstructionValve Body

Two Way Three Way

Bonnet

Packing Flange

Packing

Valve Stem

Valve Plug

Seat

Cage

13Some Globe Valve Plugs (discs)

Various plugs shown in

yellow

Guided Disc

Basic Plug Disc

Composition Disc

14

Globe Valve Ports and Action

Reverse Action(down to open)

FLOW

Double-Ported Globe Valve

FLOW

15

Typical Gate Valve Construction

Valve Body

Bonnet

Packing Flange

PackingValve Stem

Split Disc Solid Disc

Valve Seat

16

Typical Butterfly Valve Construction

Valve Body

Packing Flange

Valve Stem

Valve Disc

Valve Seat

Bearings

Packing

Packing

17

Typical Ball Valve Construction

Valve Body

Packing Flange

Packing

Valve Stem

Ball

Valve Seat

Bearings

Bonnet

18% Valve Travel

% F

low

0

100

100

50

50

75

75

25

25

Linea

r

Qui

ck O

peni

ng

Equa

l Per

cent

age

Ideal FlowCharacteristics

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Plug and Seat Flow Characterization

Linear Equal Percentage

Quick Opening

20

Trim Cage Flow Characterization

21

Drag Valve Trim

22

Diaphragm Actuator Construction

Diaphragm Casings

Diaphragm

Diaphragm Plate

Actuator Spring

Actuator Stem

Spring Seat

Spring Adjustor

Stem Connector

Travel Indicator Disk

Indicator Scale

Yoke

Seal Bushing

23

O-RingPositioner

Piston Rod Extension

Piston Rod Boot

Cylinder

Piston / Rod

Lower Seal Bushing

Upper Seal Bushing

Yoke

24

25

Braided Ring

Braided Ring

Graphite Rings

CarbonSpacer

PackingGlandFollower

Va

lve

Ste

m

26

27

Fisher 3582 Positioner

Principle of Operation

28

Fisher 3582Positioner

Construction

Travel Adjustment ScrewInput

Cam Beam

Pivot Pin

Flapper

Follower Assembl

y

Nozzle

Input Bellows

Rotary Shaft Arm

Nozzle

29

Cam

Guide & Roller BearingBeam

Fisher 3582 Wear Points

Beam Off Center

Cam

Guide Wear

Roller Wear and Cut

Wear caused by Guide (“locked valve position”)

Wear caused by siezed roller

30

Fisher 3570PositionerPrinciple of Operation

31

3570 Positioner

Construction

Air Supply

Cylinder (Top)

Cylinder (bottom)Input

Bias Spring

Range Spring

Horizontal Relay

Vertical Relay

Input Bellows

Bellows Post

Beam

32

33

34

NAMCO Position Switches

Operating Lever

Clamping Screw

Lever Locking Pipe PlugContacts

Cover / Gasket

35

Simplified LVDT

PositionSignals

Excitation

36

P&ID symbols for SOV’s

S

S

S

S

S

S

De-Energized Energized

2-Way

3-Way

4-Way

37

Typical SOV Construction

Coil

Cover

Yoke

Housing

Solenoid Base

Core Assembly

Body

Disc Assembly

End Cap

38

Fisher 546 I/P

39Fisher 546 I/P Construction

Air SupplyOutp

ut

Input

Zero

Span

Torque Motor

AssemblyShunt Pivot(behind Torque

Motor)

40

FO

FO

FC

FC

FC

FC

S

S

41

FO

FO

FC

FC

FC

FC

S

S

S

42

FO

FO

FC

FC

FC

FC

S

S

S

43

44