Valve Concepts 3000 Series Installation, Operation And Maintenance Manual

ISO Registered Company
I. 3000 SERIES DESIGN AND FUNCTION
MODEL P V
3100 P V
3200 P V
3300 V
3400 P
3500 P
3600 V
3700 P
3800 P
Models 3100 through 3600 Pressure and /or Vacuum
Vents are used for the normal venting requirements.
Normal venting is defined as venting required
because of operational requirements (i.e. filling and
emptying the tank) or atmospheric changes. Models
3700 and 3800 Emergency Relief Vents are used to
meet venting required when an abnormal condition,
such as an external fire or such as ruptured internal
heating coils, exist either outside or inside the tank.
All of these devices are sized in accordance with API
Standard 2000. Improperly specified relief vents may
result in structural damage to the tank or system and
can cause severe personal injury or death.
Figure 1 - Pressure Relief
INSTALLATION, OPERATION AND MAINTENANCE MANUAL
Model 3400
Pressure Relief Vent
DESCRIPTION
Vent to Atmosphere
Vent to Header
Top Mounted
Vent to Atmosphere
Vent to Header
Side Mounted
Emergency/Manhole Cover
Emergency/Top Guided Relief
SECTION I
Figure 1 illustrates the operation of the Pressure/
Vacuum Relief Vent under overpressure conditions.
As the tank pressure increases as a result of product
being pumped into the tank and/or because of thermal
expansion of the product and vapors, the pressure
pallet remains closed until the set pressure of the
vent is reached. When the tank pressure reaches the
pressure setting of the vent, the pressure pallet lifts
allowing the tank pressure to bleed off.
Figure 2 illustrates the operation of the Pressure/
Vacuum Relief Vent under vacuum conditions.
As the tank pressure decreases as a result of product
being pumped out of the tank and/or because of
thermal contraction of the product and vapors, the
vacuum pallet remains closed until the set vacuum of
the vent is reached. When the tank vacuum reaches
the vacuum setting of the vent, the vacuum pallet lifts
allowing air to be drawn into the tank.
Figure 2 - Vacuum Relief
IOM-3400
10-20