Product Descriptions
The 67D Series direct-operated regulators are typically
used to provide constantly controlled, reduced pressures.
They are suitable for most air or gas applications.
• The Types 67D and 67DS are the standard
instrument supply regulators without a filter or
internal relief.
• The Types 67DF and 67DFS are equipped with a
filter for removing particles from the supply gas.
• The Types 67DR and 67DSR have an internal relief
valve with a soft seat for reliable shutoff with no
discernible leakage.
• The Types 67DFR and 67DFSR have a filter and
internal relief valve with a soft seat for reliable
shutoff with no discernible leakage.
Principle of Operation
Downstream pressure is registered internally on the
lower side of the diaphragm. When the downstream
pressure is at or above the set pressure, the valve plug
is held against the orifice and there is no flow through
the regulator. When demand increases, downstream
pressure drops slightly allowing the spring to extend,
moving the stem down and the valve plug away from
the orifice. This allows flow through the regulator.
Internal Relief (Types 67DR, 67DSR,
67DFR and 67DFSR)
If for some reason, outside of normal operating
conditions, the downstream pressure exceeds the
setpoint of the regulator, the force created by the
downstream pressure will lift the diaphragm until
the diaphragm is lifted off the relief seat. This allows
flow through the token relief. The relief valve on
the Type 67DR, 67DSR, 67DFR or 67DFSR is an
elastomer plug that prevents leakage of air from the
downstream to atmosphere during normal operation,
thereby conserving plant air.
Smart Bleed™ Airset
In some cases, it is desired to exhaust downstream
pressure if inlet pressure is lost or drops below the
setpoint of the regulator. For example, if the regulator
is installed on equipment that at times has no flow
demand but is expected to backflow on loss of inlet
pressure. The Type 67DFR or 67DFSR can be ordered
with the Smart Bleed option which includes an internal
check valve for this application. During operation, if
inlet pressure is lost, or decreases below the setpoint of
the regulator, the downstream pressure will back flow
upstream through the regulator and check valve. This
option eliminates the need for a fixed bleed downstream
of the regulator, thereby conserving plant air.
Figure 2. 67D Series Operational Schematics
INLET PRESSURE
OUTLET PRESSURE
ATMOSPHERIC PRESSURE
M1153 M1154
TYPE 67DR OR 67DSR
TYPE 67D OR 67DS TYPE 67DF OR 67DFS
TYPE 67DFR OR 67DFSR
SMART BLEED OPTION FOR
TYPE 67DFR OR 67DFSR
Type XXXX
MXXXX
Month Year
Type XXXX
INLET PRESSURE
OUTLET PRESSURE
ATMOSPHERIC PRESSURE
INTERMEDIATE PRESSURE
PILOT SUPPLY PRESSURE
LOADING PRESSURE
3
67D Series