Brochure

© 2015, Maxitrol Company. All Rights Reserved. © 2015 Maxitrol Company. All Rights Reserved.
DRAFT 09.18.2013
63
Dead End Lockup
Pressure will be maintained within ANSI/CSA limits under
no ow conditions. The amount of climb above set point
is inuenced by inlet pressure, ow rate before no ow
condition and piping arrangement. Dead end lockup
pressure regulators must be properly sized for desired
performance.
Differential Pressure
The difference between inlet pressure to the pressure
regulator and outlet pressure from the pressure regulator.
To obtain differential pressure, subtract the desired outlet
pressure from available inlet pressure.
Line Pressure Regulator
A pressure regulator intended for installation in a building
gas distribution system between the building service
regulator or LP-gas 2 psi service regulator and gas utilization
equipment.
Lockup Type
Under no ow conditions, outlet pressure will rise above
adjusted pressure but will not rise to line pressure.
Minimum Capacity
(
Main Burner Only
)
Minimum capacity of a pressure regulator designed to
control the ow to the main burner only.
Maximum Capacity
(
Main Burner Only
)
Maximum capacity of a pressure regulator at which the
pressure regulator will control main burner pressure within
acceptable limits.
Maximum Capacity
(
Main Burner and Pilot
)
Maximum capacity of a pressure regulator at which the
pressure regulator will control main burner and pilot line
pressure within acceptable limits.
Capacity
Total load Btu/h of all appliances combined.
Maximum Individual Load
Largest single appliance or burner served by the pressure
regulator.
Maximum Individual Load Capacity
1. The maximum capacity or ow at which a line pressure
regulator will control lockup pressure within acceptable
limits.
2. The maximum capacity or ow at which a pressure
regulator will control pilot line pressure within
acceptable limits.
Non-Lockup Type
Under static conditions when no gas is owing, outlet
pressure will rise to line pressure.
Overpressure Protection Device
(
OPD
)
A device which under abnormal conditions will act to reduce,
restrict, or shut off the supply of gas owing into a system
to prevent pressure in that system from exceeding 2 psi.
• Monitoring Regulator: An overpressure protection device
which functions as a second pressure regulator in series
with the primary pressure regulator.
• Overpressure Relief Device: An overpressure protection
device which functions by discharging gas from the
downstream system to a safe location.
• Overpressure Shut-Off Device: An overpressure protection
device which functions by completely shutting off the
ow of gas into the downstream system.
Pressure Drop
The natural loss of pressure that occurs in the pressure
regulator (or in any valve or pipe) due to friction. This
friction impedes uid motion, without regard to articial
losses deliberately created by diaphragm action. The
equivalent ow rate for a loss in given pressure with the
pressure regulator valve in a normally wide open position.
Rated Inlet Pressure
The highest inlet pressure for which the control is intended
to be used.
Vent Limiter
A means that limits the ow of gas from the atmospheric
chamber to the atmosphere in the event of a diaphragm
rupture. This may be either a limiting orice or a ball check
vent limiting device.
• Limiting Orice Type: A vent limiter where the ow
through the limiter is the same in both directions
Zero Governors
They require an external impulse signal, such as top loading
with pressure or generating vacuum in the downstream
piping.
DEFINITIONS