Appendix C – Glossary

accelerators
quick opening device that speeds up the trip action of a dry pipe valve
air dryer
any one of several types of air dryers, such as refrigerated air dryers and desiccant air dryers
backfill
earth, soil or gravel (aggregate) used in proper placement to bury underground piping
cathodic protection
a method of grounding used primarily on steel water tanks and underground piping to prevent electrolysis
combined dry pipe/preaction system
dry pipe system that employs a supplemental detection system
cross–connection control
assemblies that prevent potentially contaminated water from flowing back into the water supply
deluge system
a system with open sprinkler heads, set up so that when the system is tripped all heads spray simultaneously
dies
equipment used to cut external threads in rod or pipe
dry pipe system
a sprinkler system charged with air, primarily used to prevent freezing in a cold environment
escutcheon (plate)
aesthetic or cosmetic plates through which sprinkler heads enter the building space (sometimes called escutcheon plates)
excess pressure pump
water pump that boosts pressure to prevent false alarms
fire pump assembly
water pump designed to supply or supplement flow and pressure dedicated to fire protection
flow switch
a device that monitors water flow and initiates an alarm signal to a fire alarm panel or equivalent
flushing connection
a connection used to flush water from piping and components; for example, at the end of a water main or hydrant
grade
the slope of a pipe or trench, usually expressed as a ratio of rise (change in elevation) to run (change in distance)
grooving (of pipe)
a process of mechanically joining pipe in which a groove is cut or pressed (rolled) around a pipe to accommodate a coupling
hangers
components installed to allow pipes to be attached overhead or to other support structures
heat-actuated detectors (HAD)
heat–activated device, triggered when a specified temperature or rate of increasing temperature is detected
laydown
a pre-determined area where material is stored
mark–ups / as–built drawing
a revised set of drawings submitted by a contractor upon completion of a project that reflect all changes made in the specifications and shop drawings during the construction process
preaction systems
a system that may or may not contain supervisory air or nitrogen that can be operated through detection or sprinkler activation
pressure switch
a device used for monitoring high or low pressure in piping system
pump room
also called pump house. A designated area or room in a building or outside a building that contains a fire pump and its components
reaming
a process to restore the pipe to its original inside diameter, usually by removing the internal burr or flare formed when the pipe was cut
seismic/sway bracing
pipe restraint system
shop drawings
a drawing or set of drawings produced by the contractor, supplier, manufacturer or subcontractor for the purpose of installing, fabricating and bidding
sleeve
installed before or after concrete or other structural placement to enable pipes to pass from one area of a structure to another
sling
any metal or synthetic flexible device used to cradle or support a load. Slings are attached to the hoist line of the lifting device to complete the lift
sprinkler guards
devices used to protect heads from damage
standpipe system
a system to which firefighting hoses may be attached
suppression systems
types include wet/dry chemical, gas, clean agent, mist, hybrid
tamper switch
device which monitors the opening or closing of a valve by sounding a signal in fire alarm panel
thrust block
concrete restraint cast in place at a critical point in underground piping installations, in order to prevent hydraulic pressure from moving or separating pipe joints
trim
smaller or auxiliary piping attached to installed devices such as valves and pumps. Often supplied as a “trim package”
valves
device placed in a pressurized piping system in order to control, direct or prevent the movement of chemicals, gases, liquids or other substances
water motor gong
a water–operated local audible alarm
wet pipe system
sprinkler system charged with water