172-65175MA-13 (COS Pressure Reducing Valve) 16 Feb 2022
14
External Secondary Pressure Sensing Line
Standard model is factory prepared for internal sensing.
A secondary pressure detection port has been added to all COS pilot bodies to allow
for installation of a 10 mm (
3
/
8
in) secondary pressure sensing line, which improves
performance and increases valve capacity (flow rate). This model is delivered with a
secondary pressure sensing line plug installed in this port. When the external sensing
method is used, follow the installation procedure shown below.
For proper use of COS
with
the external secondary pressure sensing line, follow the
installation procedure below.
1) Loosen and remove the hex bolts (nuts) that attach the pilot body to the main body
or the pilot cover (65 to 150 mm (2
1
/
2
to
4 in)) and remove the pilot body.
2) Install the provided blind pin by first removing the connecting tube from the main
body and then substituting the blind pin.
3) Re-install the pilot body and fasten the hex bolts (nuts) evenly.
4) Remove the plug Rc(PT)
3
/
8
(or NPT
3
/
8
) and connect the secondary pressure
sensing line with a slightly falling pitch.
The end of the external secondary pressure sensing line should be connected to the
place on the steam-using equipment where the pressure is to be sensed.
A shut-off valve should be installed in the external secondary pressure sensing line.
Connecting Tubes
Pilot Valve Body
Plug Rc(PT)
3
/
8
Hex Bolt (Nut)
Body
Inlet
Outlet
Blind
Pin
Replace the factory-installed connector (has
holes) with the blind pin (has no holes).
Connecting
Tube
Pilot Valve Body
Steam-using Equipment
COS
Valve
15 d or more
1 m (3.3 ft)
or 15 d,
whichever is
larger
10 mm (
3
/
8
in) Outlet
Pressure Sensing Line
(slightly falling pitch)
Piping Example:
15 to 50 mm (
1
/
2
to 2 in)
65 to 100 mm (2
1
/
2
to 4 in)
