Pre-Installation
15
Greenstar 2000 – 6 721 820 552 (2021/02)
Natural Gas (NG):
Discharge rates for copper tube with 1mbar differential pressure
between the ends for Natural Gas.
Table 9 Natural Gas
Natural Gas:
▶ When using this table to estimate the gas flow rate in pipe work of a
known length, the effective length will be increased by 0.5m for each
90° elbow and tee fitted and by 0.3m for each 45° bend.
Liquid Petroleum Gas (LPG)::
Discharge rates for copper tube with 2.5mbar differential pressure
between the ends for LPG.
Table 10 Liquid Petroleum Gas (LPG)
Liquid Petroleum Gas (LPG):
▶ When using this table to estimate the gas flow rate in pipework of a
known length, the effective length will be increased by 0.6m for each
90° elbow or tee used and by 0.3m for each 45° bend or straight
coupler used.
4.2.3
Gas supply
• Appliances using Natural Gas (NG) must be connected to a governed
meter.
• Installation and connection of the gas supply to the appliance must
be in accordance with the latest version of BS6891.
• Gas pipe sizing should be calculated to ensure no more than the
permitted mbar drop between the meter to the appliance inlet. (
chapter 6).
• The meter and pipe work to the meter must be checked, preferably by
the gas supplier. This is to ensure that the equipment is in good
working order and can meet the gas flow and pressure requirements,
in addition to the demand from any other appliance being served.
Pipe sizing (NG)
Gas pipe work:
▶ Gas installation pipe work must be designed to ensure the pressure
loss between the meter outlet (NG)
table 24 ”Allowed mbar
pressure drop”.
Basic pipe sizing calculation
Basic pipe sizing calculation.
▶
This method is only a guide - for more complex design please
refer to latest version of BS6891 and training given in ACS.
Natural Gas (NG):
Discharge rates for copper tube with 1mbar differential pressure
between the ends for Natural Gas.
Table 11 Natural Gas
Natural Gas:
▶ When using this table to estimate the gas flow rate in pipe work of a
known length, the effective length will be increased by 0.5m for each
90° elbow and tee fitted and by 0.3m for each 45° bend.
Discharge rates for Natural Gas (m
3
/hr)
with straight horizontal copper tube
Pipe
Pipe Size (mm)
Length (m)
15
22
28
35
3
2.9
8.7
18
32
6
1.9
5.8
12
22
9
1.5
4.6
9.4
17
12
Discharge
1.3
3.9
8
15
15
m
3
/hr
1.1
3.4
7
13
20
0.95
2.9
5.9
11
25
0.92
2.5
5.2
9.5
30
0.88
2.3
4.7
8.5
Discharge rates for LPG (m
3
/hr)
with straight horizontal copper tube
Tubing
length (m)
Outside diameter
15mm
22mm
28mm
kW
m³/hr
kW
m³/hr
kW
m³/hr
3
38.4
1.49
207
8.01
412
15.92
6
26.1
1.01
135
5.21
230
8.86
9
20.5
0.79
108
4.19
215
8.33
12
17.9
0.70
94
3.62
187
7.25
15
15.5
0.60
82
3.20
168
6.51
18
13.5
0.53
74
2.86
145
5.61
21
12.9
0.50
67
2.58
135
5.24
24
12.0
0.47
61
2.58
126
4,87
Discharge rates for Natural Gas (m
3
/hr)
with straight horizontal copper tube
Pipe
Pipe Size (mm)
Length (m)
15
22
28
35
3
2.9
8.7
18
32
6
1.9
5.8
12
22
9
1.5
4.6
9.4
17
12
Discharge
1.3
3.9
8
15
15
m
3
/hr
1.1
3.4
7
13
20
0.95
2.9
5.9
11
25
0.92
2.5
5.2
9.5
30
0.88
2.3
4.7
8.5