The T208 Series are direct-operated tank blanketing vapor recovery regulators. These regulators are used to sense an increase in vessel pressure and vent excessive internal tank pressure to an appropriate vapor recovery disposal or reclamation system. T208 Series may also be used as
backpressure regulators or relief valves.
Available Configurations
Type T208: Tank Blanketing Vapor Recovery regulator
with control pressure range of 2 in.w.c. to 7 psig /
5 mbar to 0.48 bar in six different spring ranges
and has internal pressure registration requiring no
downstream control line.
Type T208M: Similar to Type T208 but has a blocked
throat and a downstream control line connection for
external pressure registration.
Body Sizes and End Connection Styles
See Table 1
Maximum Allowable Inlet (Casing) Pressure(1)
See Table 1
Maximum Outlet Pressure(1)
35 psig / 2.4 bar
Maximum Emergency Inlet Pressure to Avoid Internal
Parts Damage(1)
With Nitrile (NBR) or Fluorocarbon (FKM)
Diaphragm: 35 psig / 2.4 bar
With Fluorinated Ethylene Propylene (FEP)
Diaphragm: 20 psig / 1.4 bar
Control Pressure Ranges(1)
See Table 3
Flow and Sizing Coefficients
See Table 4
Cv Coefficients and Flow Capacities
See Table 5
Orifice Size
7/16 inch / 11 mm
Body and Casing Materials
Gray Cast Iron, WCC Carbon Steel, and
CF8M/CF3M Stainless Steel(2)
Trim Materials
See Table 2
Material Temperature Capabilities(1)(3)
Nitrile (NBR):
-20 to 180°F / -29 to 82°C
Fluorinated Ethylene Propylene (FEP):
-20 to 180°F/ -29 to 82°C
Fluorocarbon (FKM):
40 to 300°F / 4 to 149°C
Ethylene Propylene Diene (EPDM):
-20 to 225°F / -29 to 107°C
Perfluoroelastomer (FFKM):
0 to 300°F / -18 to 149°C
Spring Case Vent Connection
1/4 NPT
Diaphragm Case Control Line Connection (Type T208M)
1/2 NPT
Approximate Weight
17.7 pounds / 8 kg
