©2005 McQuay International
17
Outdoor
Oil trap
(every 6~8m fall of the
gas pipe set a oil trap)
Indoor
●
Limitation of the refrigerant piping length:
MDS080~320
TUBE PIPING
Total length
Actual Length
≤
350m
L1+L2+...+Li+a+b+…+i
Actual Length
≤
125m
Max length
Equivalent length
≤
150m
L1+L2+... +Li+i
Length
of
tube
Equivalent length from the 1
st
bifurcation
to longest piping
≤
40 m
L2+L3+...+Li+i
Outdoor is in high position
≤
50 m
-
Indoor and
outdoor
Indoor is in high position
≤
40 m
-
Height
difference
Between indoors
≤
15 m
-
Note:1) When outdoor units is above the indoors units, every 6
～
8m fall of the gas pipe shall set a oil trap;
2) Equivalent length is the length to consider and deduct the turning pressure drip and tube pressure drop ;
Equivalent length =Actual number of elbow
╳
equivalent length for elbow + number of trap
╳
equivalent length for trap
For bifurcation, the equivalent length is 0.5m, branch piping 1.0m, elbow and oil trap ‘s equivalent as following table:
Equivalent length
Equivalent length
DIA.
Elbow (m
）
Oil trap (m)
DIA.
elbow (m
）
Oil trap (m)
φ
9.52
0.18
1.3
φ
28.6
0.50
3.7
φ
12.7
0.20
1.5
φ
31.8
0.55
4.0
φ
15.88
0.25
2.0
φ
34.9
0.60
4.4
φ
19.05
0.35
2.4
φ
38.1
0.65
4.7
φ
22.23
0.40
3.0
φ
41.3
0.70
5.0
φ
25.4
0.45
3.4
7
．
．
．
．
4 Insulation of refrigerant piping:
To apply the enough thickness of the insulation material to wrap the liquid and gas piping, no leakage of condensing water allowed;
●
Insulation material specification as following table:
Fiberglass
＋
Steel
Insulation Material
Adhering material
＋
Chloroethylene foam
＋
adhering strip
Indoor
Chloroethylene insulation strip
Bare floor
Water proof flax
＋
Bronze Pitch
Layer
outdoor
Water proof flax
＋
galvanized panel
＋
painting
●
Gas and liquid insulation
installation as shown as right:
H
e
ig
h
t
d
if
fe
re
n
c
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b
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tw
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o
u
td
o
o
r
a
n
d
i
n
d
o
o
r
Bifurcation
L1
a
L2
L4
L3
b
c
d
L5
i
e
H
e
ig
h
t
d
if
fe
re
n
c
e
b
e
tw
e
e
n
i
n
d
o
o
rs
Li
