Test 2 Flashcards
A plug valve is an example of a _____valve.
Rotary
T/F The disk shape of the plug valve is cylindrical or tapered shaped.
True
Plug valves operate _____ compared to gate valves.
Faster
Name two industries that use plug valves.
High Pressure Fracturing & Food Processing
Plug valves used in corrosive chemical application have a body lining of ______.
PTFE polytetrafluoroethylene also known as Teflon
Identify the following parts of a plug valve in the illustration A
Handle
Identify the following parts of a plug valve in the illustration B
Packing
Identify the following parts of a plug valve in the illustration C
Stem
Identify the following parts of a plug valve in the illustration D
Body
Identify the following parts of a plug valve in the illustration E
Plug
Identify the following parts of a plug valve in the illustration F
Plug Port
Name the six port patterns that the plug valve is available in.
Round opening, Rectangular Opening, Standard Opening, Diamond Opening, Multi-Port and Venturi design
When the plug’s opening is turned perpendicular to the flow stream, the valve is in the _____ position.
closed
With plug valves larger than 3 inch, what type of actuator is used instead of a handwheel?
Geared hand wheels Actuator
Name the four types of plug valves
Lubricated, Non-lubricated, Eccentric and Expanding
T/F Both lubricated and non-lubricated plug valves can provide a bubble tight shutoff.
True
What function does the check valve perform in association with the injection fitting?
prevents the sealant from flowing in the reverse direction once the sealant is injected into the cavity.
T/F The lubricant used in a lubricated plug valve must be compatible with the fluid in the pipeline.
True
T/F Non-lubricated plug valves are used in high temperature applications.
False
This type of non-lubricated plug valve has the body and plug fully lined with Teflon and are used with corrosive fluids.
Fully Lined
Name the type of plug valve
Eccentric Plug Valve
This type of plug valve provides a true double block and bleed function in one valve.
Expanding Plug Valve
Provide two advantages of plug valves:
Simple design and fewer parts. Provides a reliable leak-tight service.
Provide two disadvantages of plug valves:
Actuators are required for larger valves and the pressure drop is more due to reducing port
What is the P&ID symbol for the plug valve?
A butterfly valve is an example of a _____valve.
Rotary
A butterfly valve is an example of a _____valve.
parallel
T/F Butterfly valves work well in low pressure drop applications.
True
A zero offset butterfly valve is known as ______.
concentric
Offset in a butterfly valve means that the valve stem is displaced from the _____ of the disc.
Center
Name the three types of eccentric butterfly valves.
Single, double or triple offset
Double and triple offset butterfly valves are also called _____ performance butterfly valves.
High
What are the two offsets in a double offset butterfly valve?
The shaft is offset from the centerline of the disc seat and body seal (offset one), and the centerline of the bore (offset two).
What are the three offsets in a triple offset butterfly valve?
The shaft is offset from its body center line & shaft offset from pipe center line & conical offset shape in its seal and discs connection
Name the type of butterfly valve based on the top view A
Stem
Name the type of butterfly valve based on the top view B
Body
Name the components of the butterfly valve C
Flange
Name the components of the butterfly valve D
Lining
Name the components of the butterfly valve E
Bushing
Name the components of the butterfly valve F
Steam sealing
Name the components of the butterfly valve G
Pins
Name the components of the butterfly valve H
Disc
Name the type of butterfly valve based on the top
Concentric
Name the type of butterfly valve based on the top
Double-Offset
Name the two common end connections for a butterfly valve.
Lug and wafer
Name two advantages of butterfly valves.
Easy to install and Low-pressure drop
Name two disadvantages of butterfly valves.
Possibility of Cavitation and choked flow as well as Poor Sealing function
T/F The P&ID symbols for a butterfly valve are:
True
A gate valve is an example of a _____valve.
linear
T/F The disk shape of the gate valve is a flat circular or rectangular plate.
True
Name the three major components of a gate valve.
Body, bonnet, and trim
How is the bonnet typically joined to the body of a gate valve.
By means of flanged, screws or welded connections
For an underground gate valve, what is attached to the valve to provide direct access?
Extension spindle
Name the two general types of gate valves.
Parallel and Wedge
This type of gate valve has a flat disc plate between two parallel seats.
Parallel Gate Valves
What is the purpose of the springs between the two discs in the conventional parallel gate valves?
Keep the upstream and downstream seats in sliding contact with the body and to improve the seating load at low fluid pressures.
Identify the type of gate valve
Through-Conduit Gate Valve
Name two applications where this valve is used.
Transportation of crude oil and gas as dirty river water with suspended solids or water with sludge or debris
This type of gate valve is used in systems with a high concentration of suspended solids such as slurries and sewage sludge.
Knife Gate Valve
What is the advantage of using a stainless-steel knife gate valve in wastewater applications.
Less vulnerable to corrosion damage
T/F Knife gate valves work well in throttling applications.
False
How do wedge gate valves differ from parallel gate valves.
The closure member is wedge-shaped instead of parallel.
T/F The wedge gate valve has a closure member that provides a high supplemental seating load that seals against high fluid pressures.
True
Name the three types of wedge gate valves.
Solid Taper, Split Wedge, and Flexible Wedge
Label the wedge gate valve.
Solid
Label the wedge gate valve.
Split
Label the wedge gate valve.
Flexible
This type of wedge gate valve has grooves in which wedge assembly travels and provides flexibility allowing it to seal more easily.
Split
This type of wedge is a one-piece disc with a cut around the perimeter which improves seat alignment and offers better tightness. A disadvantage is that process fluid tend to collect in between the seats.
Flexible
Name the two types of valve stem designs.
Rising Stem and Non-Rising Stem Gate Valve
A rising stem gate valve requires _____ space when opened compared to the non-rising stem.
more
T/F Rising stem gate valves are suitable for below ground installations.
False
In operating a non-rising stem gate valve, the stem ______ come out of the housing.
does not
T/F Non-rising stem gate valves are suitable for both above ground and below ground installations.
True
T/F In non-rising stem gate valves, it is not easy to determine if the gate valve is fully open or fully closed.
True
What is the difference in the valve body between a metal seated gate valve and a resilient seated gate valve.
Metal seated gate valve has a depression in the valve body bottom and resilient seated gate valve has a plain valve bottom
What material does a resilient seated gate valve use to allow the gate surface to resume its original shape after sealing.
A high quality rubber compound
Gate valves are designed for ______ operation.
isolation
Gate valves have ____ pressure drop across them.
low
Define water hammering.
A surge of pressure or high-pressure wave that occurs when a fluid in motion is forced to suddenly stop or change direction
Name two conditions that happen when a gate valve is partially open.
Vibration and noise
Which of the following P&ID symbols is a gate valve?
B
A ball valve is an example of a _____valve.
rotary
T/F The disk shape of the bass valve is spherical shaped.
True
T/F Ball valves can have multiple ports.
true
Name the two most common metal materials that ball valves are manufactured from
Steel and Brass
What material is lined the wetted surface of ball valves for protection in corrosive chemical applications?
Polytetrafluoroethylene (PTFE)
Label the following parts of the ball valve A
Bonnet
Label the following parts of the ball valve B
Stem
Label the following parts of the ball valve C
Ball (Full Bore)
Label the following parts of the ball valve D
Body
Label the following parts of the ball valve E
Flanged End
Label the following parts of the ball valve F
Ball Seat
In a floating ball valve, the ball is connected to the _______.
stem
What is a trunnion and what purpose does it provide to the ball valve?
A post which are supported by bearings in the body
When the hole in the ball’s center aligns with the valve’s inlet and outlet ports, the valve is in the _____ position.
open
In applications where it is critical to minimize the risk of leaks, a ____ ball valve should be used.
trunnion
_____ ball valves are used in high pressure applications.
Trunnion
What is the critical difference between a floating ball valve and a trunnion ball valve?
The design of the ball
T/F Trunnion ball valves are less expensive than floating ball valves.
False
Name the two types of seat designs for trunnion mounted ball valves.
Single or double piston effect seats
In the absence of line pressure, what provides the force to keep the seat in contact with the ball.
Coil springs behind the seat provide a tight seal by keeping the seat in contact with the ball, even at low differential pressures
This seat design is also known as the self-relieving seat.
Single Piston Effect (SPE)
T/F The SPE design seat permits the automatic release of an overpressure in the body cavity eliminating the need for a valve body relief valve.
True
Explain what happens with the SPE seats when the pressure in the valve cavity exceeds the spring load on the seat.
The pressure can be relieved to the pressure source or to the low-pressure side, generally the downstream side
Based on the API standard, the relieving pressure in the valve body cavity shall not exceed ____ times the fully rated valve flange rating pressure
1.33
What device is required to be used to protect the valve body from over pressuring due to thermal expansion?
An external safety relief valve
Name the five types of body styles for ball valves.
Single piece body, split body, top entry, side entry and welded
This body style of ball valve has two parts that are held together by a flange connection.
Split-Body Ball Valve
This body style of ball valve allows access to the interior of the valve for disassembly and repair
Top-Entry Ball Valve
Name the two types of ball valve ports.
Full port and reduced port
This type of ball valve port is also called a standard port.
Reduced ball valve
T/F A standard port valve can cause a restriction of flow.
True
A ___ port ball valve has the same bore diameter as the internal diameter of the pipe.
Full
Name the three types of typical end connections for ball valves.
Threaded, welded and flanged
What does the “V” in V-Port ball valve represent?
Represents either the shape of the seat or the shape of the ball
V-Port ball valves are used in _______ applications.
throttling
The flow characteristic of a V-Port ball valve is close to _______.
linear
A pinch diaphragm valve is an example of a _____valve.
linear
A pinch diaphragm valve is an example of a _____valve.
Clamp or Tube Valve
T/F The flexible internal sleeve in the valve keeps the flow media isolated from the rest of the valve.
True
T/F Pinch valves require stem packing.
False
T/F Pinch valves are ideal for on /off (isolation) applications because of their straight through design that allows for uninhibited flow.
True
For pinch valves used in throttling operations, the best flow control is attained with at least ___ percent of stroke.
50
T/F It is good practice when flowing sharp media, to throttle close to shutoff (100% closed).
False
What is the result of throttling in the flowing of sharp media near 100% closed?
Particles can scratch the liner causing grooves and potential tears
The pinch valve shown is an example of an _______ pinch valve.
open
T/F When a pinch valve is opened, the force of the flow media and the rebounding property of the sleeve completely open the valve.
True
Label the parts of the pinch valve A
Stem
Label the parts of the pinch valve B
Pinching Device
Label the parts of the pinch valve C
Valve Body (Sleeve)
This part of the pinch valve is responsible for the movement of the pinch mechanism for opening or closing the valve.
the Stem
Name the four types of sleeves for pinch valves.
Standard, double-wall, cone and variable orifice sleeve
The type of sleeve is designed for throttling applications.
Cone
This type of sleeve is designed for highly abrasive applications.
Double-Wall
T/F The pinch mechanism of a pinch valve can be on one side of the tube or both sides of the tube.
True
Straight thru design of pinch valves have a _____ pressure drop.
small
Name two advantages of pinch valves
Straight Flow Path and Easy to Repair
Name two disadvantages of pinch valves.
Limited temperature & pressure range and cannot be used with gas media
How is a pinch valve different from a diaphragm valve.
Diaphragm valves use an elastomeric diaphragm to separate the flow stream from the closure element while pinch valves use an elastomeric liner in the valve body.
The P&ID symbol for a pinch valve is _______.
D
A diaphragm valve is an example of a _____valve
linear
Describe what a diaphragm is in a diaphragm valve.
The flexible “disc” that is elastomeric and fully isolated from the wetted parts
What applications are diaphragm valves used in?
Designed for leak-proof control of abrasive and corrosive liquids, slurries and pulps.
Name the two configurations that diaphragm valves are available in.
Straight-Thru and Weir Type
The straight-thru diaphragm valve is also referred to as a ____ bore diaphragm valve.
full
Diaphragm valves are typically used for ______ service.
on/off (isolation)
The diaphragm in the diaphragm valve is made of _____ material.
flexible
T/F In a raised weir diaphragm valve, the weir reduces the amount of diaphragm travel from the fully open to the fully closed position, thus reducing the amount of stress and strain in the diaphragm.
True
Weir type diaphragm valves are used for _____ flows
small
For the diaphragm valve body shown, the weir is part _____.
a. Port
b. Weir
c. Flow Passage
This part of the diaphragm valve is rounded in shape and is located above the diaphragm.
Compressor (Plunger)
This part of the diaphragm valve covers the top of the valve and contains the stem.
Bonnet Assembly
T/F Diaphragms are typically made from a flexible, elastomeric material.
True
Name two advantages of diaphragm valves.
Leak proof seal and easy maintenance
Name a disadvantage of diaphragm valves.
Moderate maximum pressure of approximately 300 psi and moderate operating range of around -60 to 450 F
Name the three major types of failure of the diaphragm in a diaphragm valve.
Valve leakage, complete diaphragm rupture and diaphragm tears
. The P&ID symbol for a diaphragm valve is _____.
A
- A needle valve is an example of a _____ motion valve.
linear
Needle valves are similar in design to a _____ valve.
globe
Needle valves are typically used in ____ systems for throttling of small volumes.
isntrument
T/F Due to small size and precise control, fluids require a high degree of cleanliness.
True
The needle valve has a structure of a small plunger that is in the shape of a ______.
needle
T/F Needle valves are typically used for simple isolation applications.
False
Common port sizes for needle valves range from ___ inch up to ____ inch.
1/8, 2
Name two common end connections for needle valves.
Male and Female ends
A common application of needle valves is to provide shut off for __________.
Pressure Gauges
Name the parts of the needle valve 1
Valve handle
Name the parts of the needle valve 2
Nut
Name the parts of the needle valve 3
Bonnet
Name the parts of the needle valve 4
Valve Body
Name the parts of the needle valve 5
Seat
Name the parts of the needle valve 6
O-Ring
Name the parts of the needle valve 7
Packing
Name the parts of the needle valve 8
stem
Name the parts of the needle valve 9
Handle Screw
Name three common materials that needle valves are made of.
Brass, Bronze, & Stainless Steel
Name three advantages of a needle valve
Accurate flow control at a very low rate, smaller in size, & easy to operate
Name two disadvantages of a needle valve.
High pressure loss in the valve and not easy to determine valve position just by examining the handle position
T/F The P&ID symbol for a needle valve is
True
A globe valve is an example of a _____ motion valve.
linear
T/F Globe valves are widely used for regulating/throttling flow.
True
Globe valves have ________ pressure loss across the valve compared to ball and gate valves.
more
T/F Globe valves can be used for both gas and liquid systems.
True
T/F Globe valves are typically specified for slurry applications.
False
The opening in the seat of the globe valve is closed off with a ______.
disk/plug
Name the four common plug guiding methods used with globe valves.
Cage-Guided, Top-Guided, Stem-Guided, & Top-and Bottom-Guided
Name the three types of bodies that globe valves have.
Z Type, Y-Pattern (oblique), & Angle Pattern
Identify the type of globe valve body type shown
Z Type
This type of globe valve body has the least resistance to flow compared to the other globe valve body types
Y-Type
Identify the globe valve disk type
Plug Disc
Identify the globe valve disk type
Composition Disc
Identify the globe valve disk type
Ball Disc
What is the difference between a globe valve (with a manual actuator) and a globe control valve?
Design, operation & function. Manual require an operator to adjust the disc portion by adjusting the stem. Control valves can be fully automated and can adjust the flow rate continuously over a broad range of operating conditions
Which piece of equipment in the control loop processes the information and decides what must be done to get the process variable back to where it should be?
The controller manipulates the control valve once the measuring, comparing and calculating is done
What is an advantage of the cage-guided design globe valve with regard to flow characteristics?
Easily altered just by replacing the cage with another having different flow characteristics (size or shape of holes).
Stem guided and port guided globe valves are characterized by the _________.
shape of the plug
This type of valve plug has one or more ports drilled from top to bottom allowing pressure to equalize on both sides of the plug.
Balanced lug
What is the disadvantage of using an unbalanced valve plug?
One or more leak path when the valve is in the fully closed position
Identify the standard cage
Equal Percentage
Identify the standard cage
Linear
Identify the standard cage
Quick-Opening
For the graph below, identify the type of cage: a, b, c
a. Quick-Opening
b. Linear
c. Equal-Percentage
T/F Changing of the cage also requires the changing of the valve plug and seat ring.
False
What is the ANSI standard that establishes the benchmark standard for control valve seat leakage?
ANSI standard FCI 70-2, Control Valve Seat Leakage
The ANSI standard in question 21 establishes ____ seat leakage classes.
six
In a Class ___ leakage classification, no actual shop test of the valve is made.
I
This Class leakage classification is known as a soft seat classification (intended for resilient seating valves.
VI
In a Class ___ leakage classification, the threshold is 0.5% leakage of full open valve capacity with a test medium of air at 45 to 60 psig and a service differential pressure or 50 psid.
II
In a Class ___ leakage classification, the threshold is 0.01% leakage of full open valve capacity with a test medium of air at 45 to 60 psig and a service differential pressure or 50 psid.
IV
Name the two most used leakage classifications.
Class IV & Class VI
Name two applications for globe valves.
Regulating/throttling process & used extensively in power plants, process plants, & wastewater plants.
Name two advantages of globe valves.
Durability and long service life & excellent for throttling fluid flow.
Name two disadvantages of globe valves.
High pressure loss across the valve (obstruction in the fluid flow path) & Heavier compared to other types of valves.
The P&ID symbol for a globe valve is ____.
C
