7
MD
Steam Main
Size (in)
Drip Leg
Diameter
(in)
Supervised
Warm-Up
(in)
Automatic
Warm-Up
(in)
1/2 1/2 10 28
3/4 3/4 10 28
1 1 10 28
2 2 10 28
3 3 10 28
4 4 10 28
6 4 10 28
8 4 12 28
1061528
1261828
1482128
1682428
18 10 27 28
20 10 30 30
24 12 36 36
Table 7-1. Recommended Steam Main and Branch
Line Drip Leg Sizing
H
Drip Leg
Length Minimum
Figure 7-2. Trap draining drip leg at
riser. Distance "H" in inches ÷ 28=
psi static head for forcing water
through the trap.
Figure 7-1. Trap draining strainer
ahead of PRV.
Figure 7-3. Piping for runout less than
10 ft. No trap required unless pitch
back to supply header is less than ½"
per ft.
Figure 7-5. Piping for runout greater than 10'. Drip leg and trap required ahead
of control valve. Strainer ahead of control valve can serve as drip leg if
blowdown connection runs to an inverted bucket trap. This will also minimize
the strainer cleaning problem. Trap should be equipped with an internal check
valve or swing check installed ahead of the trap.
Figure 7-4. Trap draining drip leg on main.
Step 5: Supply Steam Piping
Supplying quality steam (not wet) to the HumidiPack/
HumidiPackPlus is an important component for proper
operation. Care must be taken that the main supply
header is dripped sufficiently as well as the runout
piping to the Armstrong ACV Control Valve and
HumidiPack/HumidiPackPlus header. The entire
system must be designed and hooked up to prevent
accumulation of condensate at any point. The
following recommendations will help to ensure this.
Use drip legs and traps at all low spots or natural
drainage points such as: Ahead of risers; End of
mains; Ahead of expansion joints or bends; Ahead of
valves or regulators. Install drip legs and drain traps
even where there are no natural drainage points (See
Figures 7-1 thru 7-5).
On a supervised warm-up, make drip leg length at
least 1½ times the diameter of the main, but never less
than 10". Make drip legs on automatic warm-ups a
minimum of 28" in length. For both methods, it is a
good practice to use a drip leg the same diameter as
the main up to 4" pipe size and at least ½ of the
diameter of the main above that, but never less than 4". See Table 7-1.
10' or Less
Pitch 1/2" per 1 ft.
Runout oversized
One pipe size or more
D
H
M
More
Than
10'
Pitch 1/2" per 10 ft.
(4 Seiten)
(65 Seiten)
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Kommentare zu diesen Handbüchern