Valves (Bojoe)

Front 1

What is the purpose of a block valve?

Back 1

Block valve by definition is an on-off valve.

Front 2

Most common type of Block Valve?

Back 2

Most common type of block valve is the gate valve.

Front 3

What is the purpose of a control valve?

Back 3

The purpose of control valves is to restrict flow, thus enabling the flow of fluid to be throttled.

Front 4

Most common type of Control Valve?

Back 4

Most common type of valve used to control flow is the globe valve.

Front 5

What is the purpose of a check valve?

Back 5

Purpose of check valves is to allow for normal flow in one direction and stop any significant flow reversal

Front 6

What is the purpose of a pressure relief valve?

Back 6

Pressure safety valves are used to automatically release excessive pressures.

Front 7

Identify the typical components of a valve.

A.

Back 7

A. Actuator (Hand Wheel)

Front 8

Identify the typical components of a valve.
B.

Back 8

B. Packing

Front 9

Identify the typical components of a valve.
C.

Back 9

C. Bonnet

Front 10

Identify the typical components of a valve.
D.

Back 10

D. Stem

Front 11

Identify the typical components of a valve.
E.

Back 11

E. Body

Front 12

Identify the typical components of a valve.
F.

Back 12

F. Disk

Front 13

Identify the typical components of a valve.
G.

Back 13

G. Seat

Front 14

What is valve trim?

Back 14

Internal elements of valve collectively referred to as valve trim.

Front 15

Valve Trim typically includes: (4)

Back 15

Disk
Seat
Stem and
Sleeves to guide stem

Front 16

What is a rising stem?

Back 16

Rising stem valve the stem rises above the hand wheel as the valve is opened.

Front 17

Identify the yoke, gland follower, packing gland, gland nuts, stuffing box, and packing:

A.

Back 17

A. Yoke

Front 18

Identify the yoke, gland follower, packing gland, gland nuts, stuffing box, and packing:
B.

Back 18

B. Gland Nuts

Front 19

Identify the yoke, gland follower, packing gland, gland nuts, stuffing box, and packing:
C.

Back 19

C. Gland Follower

Front 20

Identify the yoke, gland follower, packing gland, gland nuts, stuffing box, and packing:
D.

Back 20

D. Packing Gland

Front 21

Identify the yoke, gland follower, packing gland, gland nuts, stuffing box, and packing:
E.

Back 21

E. Stuffing Box

Front 22

Identify the yoke, gland follower, packing gland, gland nuts, stuffing box, and packing:
F.

Back 22

F. Packing

Front 23

Why are gate valves not used for throttling?

Back 23

Most flow change occurs when valve more than 60% closed which causes:
Relatively high fluid velocity & results in disk and seat wear and eventual pass-through leakage
For these reasons, gate valves normally not used to regulate or throttle flow.

Front 24

Why are Globe valves preferred for throttling?

Back 24

The characteristic of moving gradually and evenly gives the globe valve good throttling ability.

Front 25

What is the purpose of a needle valve?

Back 25

Needle valve is used to make relatively fine adjustments in the amount of fluid flow

Front 26

Which types of valves are operated with a 90° motion of the stem?

Back 26

Ball valves, Plug valves, & butterfly valves are all operated with a 90° motion of the stem.

Front 27

How does a wedge plug valve operate?

Back 27

A wedge plug valves operating mechanism lifts the plug off the seats, rotates the plug 90°, and then lowers the plug back onto the seats.

Front 28

Where do we use wedge plug valves?

Back 28

We use them in the Coker

Front 29

Why does a butterfly valve have a locking handle

Back 29

For throttling purposes, intermediate positions can be secured in place by handle-locking devices.

Front 30

What is the purpose of a sigh glass safety valve?

Back 30

 Used on gauge glasses to prevent leakage in the event of a gauge glass failure.

Front 31

How does a sigh glass safety valve work?

Back 31

 When the valve is closed, the stem fits against the seat, preventing flow.
 When the valve is partially open about ¼ of a turn (fill position), a pin on the bottom of the stem prevents the ball from seating as the fluid flows into the gauge glass.
 When the valve is open, a slow flow into the gauge glass can occur, but if the flow is too fast, as would occur with a gauge glass failure, the ball is forced against the seat, stopping the flow into the gauge glass.

Front 32

What is a sigh glass safety valve's normal position?

Back 32

 Normal position is 100% open

Front 33

What are the three main classifications of valve actuators?

Back 33

 Pneumatic – air pressure.
 Hydraulic – liquid pressure.
 Electric actuators – solenoids and motors.

Front 34

In what position will an air to open fail?

Back 34

It will fail in the close position.

Front 35

How does a diaphragm actuator work?

Back 35

Diaphragm Actuators use air pressure to produce the mechanical motion required to position a valve.

Front 36

How does a piston actuator work?

Back 36

Piston actuators operate basically the same as diaphragm actuators.
Vertical piston actuators used in place of diaphragm actuators for Valves requiring:
Significant force to operate, or large stem-travel distance.

Front 37

What is the purpose of a positioner?

Back 37

Automatically adjusts actuator’s air output to diaphragm to maintain desired position in proportion to input signal.

Front 38

How does a positioner work?

Back 38

Positioner rapidly supplies a large volume of air to the actuator causing prompt movement to a new valve position.

Front 39

How does a solenoid actuator work?

Back 39

When current flows through coil a magnetic field is produced. As a result, coil becomes an electromagnet. Magnetic attraction pulls the plunger toward center of coil. When current flowing through coil stops the magnetic field is lost and Spring pushes iron core plunger and stem back to original positions which closes valve.

Front 40

Draw a typical control valve station

Back 40

Front 41

What concerns must be addressed when bypassing a control valve?

CHECK THIS ONE NOT SURE

Back 41

Ensure that you understand what effect bypassing a control valve will have on process flow, pressure, or temperature.

Front 42

When placing a control valve in automatic?

CHECK THIS ONE NOT SURE

Back 42

You must maintain communication with PTL

Front 43

How does an electric motor valve actuator work?

Back 43

The drive gear rotates the attached lug against the stem nut that then engages the threaded valve stem, which raises or lowers the stem and valve disk.

Front 44

What are the safety concerns for using manual handwheel on a motor operated valve?

Back 44

Forcing the actuator beyond the actuator’s designed torque/thrust limits.
Causing damage to the valve body which may cause loss of containment.

Front 45

How does a conventional PRV work?

Back 45

Disk blocks the path between the inlet and the outlet when system pressure is normal.
Firm and even contact between the disk and the seat prevents fluid from leaking around the disk.
The spring holds the disk in place against the seat to resist normal system pressure.

Front 46

What is the purpose of a thermal relief?

Back 46

Thermal PRV’S release excess pressure that results from an increase in temperature.

Front 47

What is the special purpose of a balanced bellows relief? ?
How does it do this?

Back 47

 Balanced bellows PRVs are similar to conventional PRVs, but are designed to minimize the effect of outlet back pressure on valve performance.

With the balanced bellows valve, outlet back pressure has little effect on set pressure. The balanced bellows balances the valve disk by venting the interior of the bellows through the bonnet chamber to the atmosphere

Front 48

Safety concerns with bellows vent port?

Back 48

 Safety concerns are that process material from the discharge side to be released to the atmosphere

Front 49

1.What is the special purpose of a pilot actuated relief valve?
2.How does it work?

Back 49

1. Pilot operated valves use process pressure instead of a spring to keep the valve closed to greatly minimize the backpressure

2.Pilot operated PRVs have a main valve combined with and controlled by a self-actuated auxiliary valve or pilot valve. Pilot operated valves use process pressure instead of a spring to keep the valve closed. The piston and seating arrangement in the main valve is designed so that the bottom surface area of the piston/disc, exposed to the inlet fluid, is less than the surface area of the top of the piston. Resultant downward force, therefore, holds the piston firmly on the piston’s seat. When inlet pressure reaches pilot set pressure, pilot valve opens to release fluid pressure above PRV piston to the discharge header. Inlet pressure exceeding pressure above the piston/disk causes main valve to pop open, allowing the process fluid to discharge.

Front 50

How does a rupture disk work?

Back 50

As process pressure increases beyond allowable operating pressure, rupture disk starts to grow until the tensile strength of the material is reached and rupture occurs.

Front 51

1.What is the purpose of a pressure vacuum vent?

2.How does it work?

Back 51


1.Located on tank roof, PV vent protects tank from overpressure and under-pressure (or vacuum) conditions.

2.When tank pressure increases, tank vapors lift pressure valve (called a pallet), allowing the vapors to flow out.
 When tank pressure decreases, atmospheric pressure lifts vacuum valve, allowing air to flow into the tank.

Front 52

What is the required position for the inlet and outlet block valves on a PRV?

Back 52

 Inlet and outlet block valves must be car sealed open (CSO) when the process is in service.

Front 53

How should the block valves be installed?

Back 53

 PRV block and bypass valves are typically installed in a horizontal orientation

Front 54

What is the purpose of snuffing steam on atmospheric PRVs?

Back 54

Steam is used if the PRV has opened and released flammable material or is leaking and caught fire.
Unit personnel steam the vents to extinguish vent fires.
Vents are also steamed during severe weather conditions, such as a thunderstorm, to prevent fires from leaking PRVs.

Front 55

How do you adjust valve packing?

Back 55

One flat per turn, evenly across both gland nuts

Front 56

Identify the types of valves and valve actuators (including their components)

Back 56

Rising Stem Gate Valve

Front 57

Identify the types of valves and valve actuators (including their components)

Back 57

Gear Driven Knife Gate Valve

Front 58

Identify the types of valves and valve actuators (including their components)

Back 58

Z-Body Globe Valve

Front 59

Identify the types of valves and valve actuators (including their components)

Back 59

Angle Body Globe Valve

Front 60

Identify the types of valves and valve actuators (including their components)

Back 60

Needle Valve

Front 61

Identify the types of valves and valve actuators (including their components)

Back 61

Plug Valve

Front 62

Identify the types of valves and valve actuators (including their components)

Back 62

Ball Valve

Front 63

Identify the types of valves and valve actuators (including their components)

Back 63

Weir Type Diaphragm Valve

Front 64

Identify the types of valves and valve actuators (including their components)

Back 64

Split Disc/Wafer Check Valve

Front 65

Identify the types of valves and valve actuators (including their components)

Back 65

Pinch Valve

Front 66

Identify the types of valves and valve actuators (including their components)

Back 66

Butterfly Valve

Front 67

Identify the types of valves and valve actuators (including their components)

Back 67

Swing Type Check Valve

Front 68

Identify the types of valves and valve actuators (including their components)

Back 68

Float To Lift Type Check Valve

Front 69

Identify the types of valves and valve actuators (including their components)

Back 69

Spring Assisted Ball Check

Front 70

Identify the types of valves and valve actuators (including their components)

Back 70

Excess Flow Ball Check Valve / Sight Glass Safety Valve

Front 71

Identify the types of valves and valve actuators (including their components)

Back 71

Pneumatic Diaphragm Actuator

Front 72

Identify the types of valves and valve actuators (including their components)

Back 72

Double Acting Piston Actuator

Front 73

Identify the types of valves and valve actuators (including their components)

Back 73

Field Reversible Horizontal Pneumatic Piston Actuator

Front 74

Identify the types of valves and valve actuators (including their components)

Back 74

Positioner

Front 75

Identify the types of valves and valve actuators (including their components)

Back 75

Pneumatic Operated ¼ Turn Valve

Front 76

Identify the types of valves and valve actuators (including their components)

Back 76

Solenoid Actuator

Front 77

Identify the types of valves and valve actuators (including their components)

Back 77

Motor Operated Valve

Front 78

Identify the types of valves and valve actuators (including their components)

Back 78

Conventional Pressure Relief Valve

Front 79

Identify the types of valves and valve actuators (including their components)

Back 79

Balanced Bellows Pressure Relief Valve

Front 80

Identify the types of valves and valve actuators (including their components)

Back 80

Pilot Operated Pressure Relief Valve

Front 81

Identify the types of valves and valve actuators (including their components)

Back 81

Pressure/Vacuum Vent Relief Valve

Front 82

Identify the types of valves and valve actuators (including their components)

Back 82

Rupture Disk

Front 83

Name the components:(Conventional Pressure Relief Valve)
A.

Back 83

A. Adjusting Screw

Front 84

Name the components:(Conventional Pressure Relief Valve)
B.

Back 84

B. Spring

Front 85

Name the components:(Conventional Pressure Relief Valve)
C.

Back 85

C. Disk

Front 86

Name the components:(Conventional Pressure Relief Valve)
D.

Back 86

D. Body

Front 87

Name the components:(Conventional Pressure Relief Valve)
E.

Back 87

E. Outlet

Front 88

Name the components:(Conventional Pressure Relief Valve)
F.

Back 88

F. Seat

Front 89

Name the components:(Conventional Pressure Relief Valve)
G.

Back 89

G. Inlet

Front 90

Name the components:(Balanced Bellows Pressure Relief Valve)
A.

Back 90

A. Bonnet Vent

Front 91

Name the components:(Balanced Bellows Pressure Relief Valve)
B.

Back 91

B. Bellow

Front 92

Name the components:(Pilot Operated Pressure Relief Valve)
A.

Back 92

A. Piston Seal

Front 93

Name the components:(Pilot Operated Pressure Relief Valve)
B.

Back 93

B. Seat

Front 94

Name the components:(Pilot Operated Pressure Relief Valve)
C.

Back 94

C. Dome

Front 95

Name the components:(Pilot Operated Pressure Relief Valve)
D.

Back 95

D. Pilot Valve

Front 96

Name the components:(Pilot Operated Pressure Relief Valve)
E.

Back 96

E. Pressure Pick up