Installation
25
20026897
4.12.1 Gas pressure
The adjacent diagrams are used to calculate manifold pressure
taking into account combustion chamber pressure.
Gas manifold pressure measured at test point 1) (Fig. 31), with:
• combustion chamber at 0” WC
• burner operating at maximum output
• Combustion head adjusted as indicated in diagram (Fig. 22)
Calculate the approximate high fire output of the burner as follows:
– subtract the combustion chamber pressure from the gas pres-
sure measured at test point 1) (Fig. 31).
– Find the nearest pressure value to your result in Fig. 30.
– Read off the corresponding output on the left.
Example
• Maximum output operation
• Natural gas
• Gas pressure at test point 1)(Fig. 31) = 7.2” WC
• Pressure in combustion chamber = 1.2” WC
7.2 - 1.2 = 6.0” WC
A maximum output of 6500 MBtu/hr shown in diagram corresponds
to 6.0” WC pressure.
This value serves as a rough guide, the effective delivery must be
measured at the gas meter.
* The values are referred to the butterfly gas valve.
kW MBtu/hr
p (“WC)
2*
930 3175 0.35
996 3400 0.39
1099 3750 0.50
1202 4100 0.63
1400 4780 0.86
1500 5120 1.00
1600 5460 1.15
1700 5800 1.30
1861 6350 1.50
2051 7000 1.65
p [“WC]
Fig. 30
Burner output
D3188
To Next Page
Loading...
