# Shared Flashcard Set

## Details

Safety Valves/Steam Traps
Homework #5
20
Engineering
Professional
07/21/2009

Term
 A boiler is equipped with one safety valve, where will it be set to blow?
Definition
 At or below the Max Allowable Working Pressure
Term
 A boiler is equipped with three safety valves, where can they be set?
Definition
 One valve would be set at or below the M.A.W.P., one could be set 3% above the M.A.W.P., and the third would be within 10% of the highest set safety valve.
Term
 Where is the super heater safety valve set?
Definition
 The super heater safety valve is the lowest set safety valve to assure flow through the super heater to prevent overheating
Term
 Name three methods used to determine the minimum safety valve relieving capacity
Definition
 Table PG-70 (Code constants), Code formula(W= CxHx.75) divided by 1100), Accumulation test, and by measuring the maximum evaporative capacity of the feed water
Term
 Why does a safety valve pop open?
Definition
 due to the huddling chamber, i.e. an increased area of the disk is subjected to high pressure steam quickly overcoming spring tension
Term
 What type of valve(s) are permitted between the boiler and the safety valve?
Definition
 None
Term
 How are soot blowers classified?
Definition
 Retractable or Stationary
Term
 What precautions should be taken prior to soot blowing?
Definition
 Increase air flow, drain steam lines to soot blower(s), blow soot from the furnace outward
Term
 How are opacity excursions handled during soot blowing?
Definition
 stop blowing soot and proceed slowly to avoid further excursions
Term
 If you fail a written exam, when can you apply again?
Definition
 After 90 days
Term
 What is the purpose of a steam trap?
Definition
 Increase overall efficiency by removing air and water from steam lines without a loss of steam
Term
 Name three types of steam traps
Definition
 Inverted Bucket, Flat & Thermostatic (F&T), Thermodynamic
Term
 Describe the operation of any single steam trap
Definition
 Thermostatic: A temperature sensitive bi-metallic strip opens and closes a valve. It reacts to the difference in temperature between the steam and condensate and closes due to Live Steam
Term
 How would you know a steam trap was not working?
Definition
 Steam process not working, trap not cycling, low or no temperature differential across the trap, high temperature condensate returns
Term
 If you fail a written exam, how soon can you apply again?
Definition
 After 90 days
Term
 Where is a non-return valve located?
Definition
 As close to the boiler as possible
Term
 Explain how you would find the true water level
Definition
 Open drain to water column and close, Open gauge glass drain and blow out the top and bottom gauge glass connections independently and close gauge glass drain. Check water level with tri-cocks
Term
 How often must air tanks be inspected?
Definition
 Air tanks operating at 50PSI and above should be inspected every two years
Term
 How often should high pressure boilers be blown down?
Definition
 At least once a day, it is better to base the blow down frequency on water analysis
Term
 Can you stop a safety valve from chattering by taking up on the adjusting nut?
Definition
 You should not. Only be made by the manufacturer or his authorized representative
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