Safety And Field Work Flashcards
Two types of bypass dampers
Barometric and motorized
What will happen to a zone system without a bypass?
Too much air may go to one zone
How does a multi zone unit control the temp of the air?
Mixing different airstreams at central unit
Standard VAV box without reheat could also be called?
Single duct terminal unit
Explain how a VAV works
Cool air supplied like normal, on call for heat, damper to cool air shut off, fan starts pulls warm air from air plenum, if more heat required reheat cool energized
Explain how induction terminal units work
High pressure primary air shot across coil, venturi effect draws secondary air from took to coil
Powder actual tools are designed for use of what type of load?
Static load, not intended for dynamic loads
High velocity powder actuated tools are ________________
No longer used in north America due to better low velocity options
Max speed of powder actuated tools
90M or 295 FPS
Three different power load calibers?
.22 .25 .27
Power load ends for low velocity tools?
Crimped ends
12 different load strengths of powder actuated tools based on color
Brass and Nickel case covers *
Gray
Brown
Green
Yellow
Red
Purple
Powder actuated tools shot distance from edge?
3” from edge
No more than 3” from Fastner to fastner
How does a powder actuated fastner work ?
Fastner displaces base material which compresses the area around fastner.
Fall protection needed if ?
Fall from 3m possible without guard rails
