37
Fig. 33 — Low, Medium or High Pressure Coil Piping
Fig. 34 — Dripping Steam Supply to Condensate
Return
Fig. 35 — Multiple Coil High Pressure Piping
* When end of supply main, see Fig. 34.
NOTES:
1. Flange or union is located to facilitate coil removal.
2. Flash trap may be used if pressure differential between steam and
condensate return exceeds 5 psi.
3. When a bypass with control is required.
4. Dirt leg may be replaced with a strainer. If so, tee on drop can be
replaced by a reducing ell.
5. The petcock is not necessary with a bucket trap or any trap which
has provision for passing air. The great majority of high or medium
pressure returns end in hot wells or deaerators which vent the air.
Note 1
Unit
Control Valve (Note 3)
Strainer
Gate Valve
Steam Supply
Main
*
Gate Valve
Condensate
Return Main
Float or
Bucket Trap
(Note 2)
15° Check Valve
Dirt Leg (6 in.)
12"
Min.
Note 1
1/2 in. Line
15° Check Valve for
Breaking Vacuum
1/4 in. Pet Cock for
Continuous vent
NOTES:
1. A bypass is necessary around trap and valves when continuous
operation is necessary.
2. Bypass to be the same size as trap orifice but never less than
1/2 inch.
Gate
Valve
Steam
Supply
to Unit
Dirt Leg
Globe Valve
(Plug Type)
Drip
Line
Condensate
Return
From Unit
Gate Valve
Condensate
Return Main
Open Air Relief to
Atmosphere Close
to Unit. Required on
Low Pressure Gravity
Return Systems
Steam Supply Main
Gate Valve
Float and Thermostatic
Trap
Unit
Unit
Note 1
1/4" Pet Cock
for Continuous
Vent
Strainer
Control Valve (Note 2)
Gate Valve
Steam
Supply
Main
See Note 7
15° Check Valve
for Breaking Vacuum
1/4" Pet Cock for
Continuous Vent
12" Min.
15° Check Valve
Gate Valve
Condensate
Return Main
Dirt Leg (6")
Float or Bucket
Trap (Note 3 and 4)
NOTES:
1. Flange or union is located to facilitate coil removal.
2. When a bypass with control is required.
3. Flash trap can be used if pressure differential between supply
and condensate return exceeds 5 psi.
4. Coils with different pressure drops require individual traps. This
is often caused by varying air velocities across the coil bank.
5. Dirt leg may be replaced with a strainer. If so, tee on drop can be
replaced by a reducing ell.
6. The petcock is not necessary with a bucket trap or any trap
which has provision for passing air. The great majority of high
pressure return mains terminate in hot wells or deaerators which
vent the air.
7. When dripping steam supply main to condensate return, refer to
Dripping Steam Supply to Condensate Return figure.