TPC 347 Valve Maintenance and Piping System Protection Flashcards
A bellows gauge is used to measure
Pressure
Install pneumatic piston actuators with the valve in the __________ position; install electric actuators with the valve in the __________ position.
Open; closed
Why are bimetallic gauges manufactured with different stem lengths?
To allow placement where the temperature is being measured
Which of the following devices is used to measure fluid pressure?
Bourdon tube gauge
A mechanism used to open or close a valve is called a(n)
Actuator
The maximum air pressure for pneumatic diaphragm actuators is approximately ________ psig.
30psig
What is the purpose of tracing a pipeline?
Maintain fluid temperature
Condensate in a steam tracing system should be drained to the
not blowdown valve; collection header
A Btu is a unit of __________ measurement.
Heat
One of the most common signs of insulation failure in steam lines is
Leakage
Which of the following describes the heat produced by the sun’s rays?
Radiation
One of the disadvantages of electric tracers is that they
Require constant monitoring
The two basic types of butterfly valve are _________ and __________.
Water; lug
For most pop safety valves, pressure and temperature conditions are usually limited to
250 and 400
Chatter in pop safety valves is caused by a _______ volume of flow at a _______ pressure.
Low; high
The basic function of a relief valve is to maintain a constant
Pressure at its inlet
What causes a pop safety valve to open?
Pressure rising above a preset level
What is the maximum amount a pop safety valve can be adjusted from the preset pressure level?
10%
The first part of a diaphragm valve to wear out is usually the
Diaphragm
If the stem of a globe valve does not move freely, one likely cause is a
Damaged spot on the thread
Which type of wrench should be used on a valve body when connecting it to a pipe?
Do not use a wrench on the valve body
Which type of valve requires a lubricant to hold a film between surfaces?
Plug
The cold service rating of a valve is usually identified by the letters
W.O.G.
The first step in stopping leakage around the stuffing box of a gate valve is to
Tighten the gland bolt nuts
A vertical lift check valve must be installed with the inlet side
On the bottom
Which of the following valve materials is the best choice for service conditions that include high pressures, high temperatures, and a corrosive fluid?
Stainless steel
Which wrench type should you use on a pipe with a polished finish?
Strap wrench
Which type of check valve is useful for reducing water hammer?
Spring-loaded check
Which material is commonly used for constructing smaller-size valves?
Standard cast iron
The marking “WOG” on the body of a valve stands for
Cold water, oil, and gas
Which of the following valve materials is most likely to be used in high-pressure, high-temperature conditions?
Steel
Valves operate most efficiently when installed
Upright
