2000 Hook-up Book - Spirax Sarco

Figure II-8
Draining Steam Main where Trap
must be at Higher Level
Steam
Main
Generous
Collecting
Pocket
L
Loop Seal
(where “L”
exceeds “H”)
Spira-tec
Loss
Detector
Figure II-9
Condensate Drainage to Reinforced Plastic Return Line, with Overheat Protection
On some extended sites,
steam distribution is underground
and drip points are
inside “steam pits”. Steam
main drip traps should discharge
into gravity return
systems, but at times it may be
necessary to connect them
directly to a pumped condensate
line. To avoid failure of
plastic or fiberglass piping
caused by high temperature
from steam leakage when
eventually the trap becomes
worn, a cooling chamber and
control as shown can be used.
If the temperature of the condensate
leaving the chamber
ever reaches the safe limit, the
control valve opens.
Condensate is discharged
above grade, where it can be
seen, until its temperature falls
again below the limiting value.
Condensate
Return Pipe
Check
Valve
H
Cooling
Chamber
Diffuser
Set down
about 2"
Thermo-
Dynamic
Steam Trap
with Integral
Strainer
Condensate
Main
In some cases, the existence of other service or process
lines alongside the stream main is combined with the
need to lift the condensate from the drip point to higher
level. Without the loop seal, clearance of condensate from
length L and replacement with steam means that for
appreciable times steam passes up length H and holds
the trap closed, although condensate may be collecting in
the pocket. The arrangement shown minimizes this problem
and gives most consistent performance of the trap.
T44 Temperature Control
(set to open at temperature
limit of pipe)
Check
Valve
Main Drip
Steam Trap
Spira-tec
Loss
Detector
High
Temperature
Drain
Steam Main
Supervised
Start-up
Valve
87
HOOK-UP DIAGRAMS