Question No. 101
What is Spiral sock valve?
Answer: A valve used to control
flow of powders by means of a twistable fabric tube or sock.
Question No. 102
What is Throttling valve?
Answer: Any valve used to
closely regulate flow in the just-open position.
Question No. 103
What is Vacuum breaker?
Answer: A special self-acting
valve or any valve suitable for vacuum service, operated manually or
automatically, installed to admit gas (usually atmospheric air) into a vacuum
or low-pressure space. Such valves are installed on high points of piping or
vessels to permit draining and sometimes to prevent siphoning.
Question No. 104
What is Quick acting valve?
Answer: Any on/off valve rapidly
operable, either by manual lever, spring or by piston, solenoid or lever with
heat-fusible link releasing a weight which in falling operates the valve. Quick
acting valves are desirable in lines conveying flammable liquids. Unsuitable
for water or for liquid service in general without a cushioning device to
protect piping from shock.
Question No. 105
What is diverting valve?
Answer: This valve switch flow
from one main line to two different outlets. WYE type and pneumatic control
type with no moving part.
Question No. 106
What is sampling valve?
Answer: Usually of needle or globe
pattern, placed in branch line for the purpose of drawing all samples of
process material through the branch.
Question No. 107
What are blow off valve?
Answer: It is a variety of globe
valve confirming with boiler code requirements and specially designed for
boiler blow-off service. WYE pattern and angle type, used to remove air and
other gases from boilers etc.
Question No. 108
What is relief valve?
Answer: Valve to relieve excess
pressure in liquids in situations where full flow discharge is not required,
when release of small volume of liquid would rapidly lower pressure.
Question No. 109
What is safety valve?
Answer: Rapid opening (popping
action) full flow valve for air and other gases.
Question No. 110
What is foot valve?
Answer: Valve used to maintain a
head of water on the suction side of sump pump, basically a lift check valve
with integrated strainer.
Question No. 111
What is float valve?
Answer: Used to control liquid
level in tanks, operated by float, which rises with liquid level and opens the
valve to control water level. It can also remove air from system, in which
case, air flows out of system in valve open condition, but when water reaches valve,
float inside valve raises to close the valve and stop flow of water. Used in
drip legs.
Question No. 112
What are flush bottom valves?
Answer: Special type of valves
used to drain out the piping, reactors and vessels, attached on pad type
nozzles.
Question No. 113
What are types of flush bottom valves?
Answer: Valves with discs
opening into the tank and valves with disks into the valve.
Question No. 114
What are the uses of three-way valve?
Answer: Alternate connection of
the two supply lines to a common delivery vise versa, isolating one safety
valve, division of flow with isolation facility.
Question No. 115
What are uses of four way valve?
Answer: Reversal of pump suction
and delivery, By pass of strainer or meter, reversal of flow through filter,
heat exchanger or dryer.
Question No. 116
What is metal seated lubricated plug valve?
Answer: A plug valve with no
plastic material, where grease is applied to contacting surfaces for easy operation.
Question No. 117
What are three patterns of plug valve
design?
Answer: Regular pattern, short
pattern and ventury pattern.
Question No. 118
What is regular pattern plug valve?
Answer: Rectangular port, area
almost equal to pipe bore, smooth transition from round body to rectangular
port, for minimum pressure loss.
Question No. 119
What are short pattern plug valve?
Answer: Valves with face to face
dimension of gate valve, as a alternative to gate valve.
Question No. 120
What are ventury pattern plug valve?
Answer: Change of section
through the body throat so graded to have ventury effect, minimum pressure
loss.
Question No. 121
What are inverted plug design valve?
Answer: Plug valve with taper
portion up of plug. For 8” and higher size.
Question No. 122
What is pressure balanced plug valve?
Answer: With holes in port top
and bottom connecting two chambers on top and bottom of plug, to reduce turning
effort.
Question No. 123
What are Teflon sleeved plug valve?
Answer: PTFE sleeve between plug
and body of valve, low turning effort, minimum friction, temperature
limitation, anti static design possible.
Question No. 124
What are permasil plug valve?
Answer: Plug valves with Teflon
seat instead of sleeves, for on-off applications, can handle clean viscous and
corrosive liquids, Graphite seat for high temperature applications. Drip tight
shut off not possible.
Question No. 125
What are eccentric plug valve?
Answer: Off center plug,
corrosive and abrasive service, on off action, moves into and away from seat
eliminating abrasive wear.