Chapter 2- Steam Boiler Fittings Flashcards
What is Safety Valve?
An automatic, full opening, pop action valve that is opened by overpressure in a boiler and used to relieve the overpressure before damage occurs
Is safety valve the most important valve on a boiler?
Yes
What is Chattering?
Is the rapid opening and closing of the safety valve
What is the Safety Valve capacity?
Is the amount of steam, in pounds per hour (lb/hr)
What is total force?
Is the total amount of five in pounds acting against the safety valve disc
TF= P x A
Tf is total force
P is pressure
A is Area
What is Blowback?
The drop in pressure in the boiler that occurs after the safety valve has opened
What is the code for Boiler and Pressure Vessel?
All low pressure steam boilers with more that 500 sq ft of heating surface and a steam generating capacity that exceeds 4000 lb/hr shall have two or more safety valves
What is a safety relief valve?
Is a specially designed automatic valve that can be used as a safety valve or as a relief valve
What is a try level test and how many times should it be preformed?
Is a safety valve test performed by lifting the safety valve try lever and it should be preformed every 30 days
What is a pop test and how many times should it be tested?
A safety valve test performed to determine if a safety valve opens at the proper pressure within allowable tolerances and it should be tested annually
What is a steam pressure gauge?
A boiler fitting that displays the amount of pressure in pounds per square inch (psi) inside the boiler
What is Hydrostatic Pressure and the formula?
The weight of water (0.433 psi per vertical foot)
H=V x 0.433
H= hydrostatic pressure (in psi)
V= vertical distance (in ft)
0.433= psi per vertical ft
What is a bourdon tube?
Is an oval tube shaped like a question mark that has a tendency to straighten when pressurized
What is a siphon?
A bent tube installed between the boiler and a boiler fitting that provides a water seal to prevent contact with steam
What is a vacuum?
Pressure below atmospheric pressure
What is a transducer?
A device that receives a signal representing a variable, such as temperature, pressure, or flow, and converts that signal into an electrical or digital signal that is compatible with a digital control system
What is a transmitter?
A device that sends a signal to a controller, such as a programmable logic controller or other digital controller
What is a water column?
A boiler fitting that reduces the turbulence of boiler water to provide an accurate water level in the gauge glass
What is a blowdown?
The process of evacuating (discharging) water and undesirable accumulated materials
Both water column and gauge glass should be blown down each shift
What is a bottom blowdown valves?
They are valves located on the blowdown line used to release water from the bottom of the boiler
What is Carryover?
A condition that occurs when small particles of boiler water are carried into the steam lines
What is priming?
A condition where large slugs of boiler water are carried into steam lines
What is water hammer?
A condition where a hammering or banging sound is created in steam lines when water is carried along in steam lines and hits elbows, valves , or other obstructions
What is a blowdown tank?
A vessel that prevents damage to the sewer system from steam and hot water by holding blowdown water until it is cool enough for safe discharge
