Table of Contents
Advertisement
September 1, 1997
For an expansion loop, multiply the "L" value by
2 if hard copper and long radius elbows are used.
If the the expansion loop is formed in soft copper,
the loop diameter equals "L".
Example:
For the same 84 foot run, a hard copper loop is 42
by 42 inches. A soft copper loop is 21 inches.
2L
Figure 3-10 — Expansion Loop Connection
Application
Do not exceed a 100 foot straight run without
constructing an offset or expansion loop. Place
the offset or loop in the middle of the run to mini-
mize pipe shift and joint stress.
SPECIAL PIPING FOR OPEN ROOMS
An open preparation room allows heat infiltration
from the rest of the store at a rate which may
jeopardize total refrigeration performance. Open
preparation evaporators must be piped with a
Crankcase Pressure Regulating Valve (CPR) to
protect the rest of the refrigeration system.
The CPR is field installed in the suction line(s)
from the evaporator(s). The installer is responsi-
ble for proper adjustment of the Valve (see
"Control Valve" Section for adjustment proce-
dures).
Return to Contents
2L
L
CONNECTING PARALLEL 3-WAY
VALVES
Due to the size limitations of 3-Way Valves, some
of the larger Koolgas systems will require parallel
connection to two suction stubs at the header,
using an offset tee construction. Do not use a bull
head tee.
Figure 3-11 — Connection to
Parallel Suction Stubs
RUN LENGTHS AND EQUIVALENT FEET
When figuring run lengths angle valves and elbow
90Þ are figured as additional straight pipe. The
chart below gives equivalent lengths for these
components.
Table 3-2 Equivalent Feet for
Angle Valve and Elbow-90Þ*
Tubing
Size
1
¼
2
5
¼
8
7
¼
8
1
1
¼
8
1
¼
3
8
1
5
¼
8
2
1
¼
8
2
5
¼
8
3
1
¼
8
3
5
¼
8
4
1
¼
8
*ASHRAE Fundamentals Handbook
HUSSM ANN CORPORATION • BRIDGETON, M O 63044-2483 • Printed in USA
P/N 401789
Angle
Long Radius
Valve
Elbow-90Þ
6
0.9
7
1.0
9
1.4
12
1.7
15
2.3
18
2.6
24
3.3
29
4.1
35
5.0
41
5.9
47
6.7
3 - 7
Advertisement
Table of Contents
