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45
Propane (G31 I
3P
) Tubular Heater
The minimum allowable pre-purge time requires calculating [BS EN1020:1998 clause 6.38].
To do this only the Carbon Dioxide CO
2
figure needs to be measured.
E.G. on a model 170 the calculated minimum time is = 898.4 / ((300 / CO2) + 2.01)
If the measured CO
2
is 8.0%
Then 300 / 8.0 = 37.5
37.5 + 2.01 = 39.51
Therefore minimum pre-purge time is = 898.4 / 39.51 =
22.7 seconds
The calculation to be conducted is given below for all models:
Model 30
Minimum pre-purge time = 1007.7 / ((300 / CO2) + 2.01)
Model 50
Minimum pre-purge time = 898.4 / ((300 / CO2) + 2.01)
Model 72
Minimum pre-purge time = 724.7 / ((300 / CO2) + 2.01)
Model 95
Minimum pre-purge time = 682.8 / ((300 / CO2) + 2.01)
Model 120
Minimum pre-purge time = 661.7 / ((300 / CO2) + 2.01)
Model 145
Minimum pre-purge time = 681.6 / ((300 / CO2) + 2.01)
The pre-purge time must then be measured. If the measured pre-purge time is lower
than the calculated time STOP and contact Harry Taylor Ltd .
Содержание HT2000
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