Fireye BurnerPRO - Calculating Valve Proving Test Times; Valve Proving Test Time Formula; Leakage Rate Standards

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CALCULATING VALVE PROVING TEST TIMES
The valve proving test times are expected to be calculated by using the following formula:
Where:
Test Time = Duration of proving time (in seconds)
∆P = Difference between inlet pressure and the switch point of pressure switch
(English -- psi, Metric -- mbar)
V
P
= Volume of test section (English -- ft
3
, Metric -- dm
3
)
C = Formula constant (3600 sec/hr)
P
AT M
= Atmospheric pressure (default 14.7 psi or 1013 mbar)
V
LEAK
= Permissible leak rate for valves (English -- ft
3
/hr, Metric -- liters/hr)
In many cases, the volume of the test section, V
P,
between the gas shutoff valves is specified in the gas train
manual. Alternatively, the volume can be calculated by:
V
P
= Volume of the test pipe between the valves + volume of the upstream valve outlet cavity + volume of the
downstream outlet cavity.
As specified in EN 1643:2014 standard, a valve proving system must be leak-tight such that:
• No single component of a VPS shall have a leak rate greater than 60 cm
3
/hr (0.00212 ft
3
/hr)
for non-integrated double block valves.
• No single component of a VPS shall have a leak rate greater than 120 cm
3
/hr (0.00424 ft
3
/hr)
for integrated or partially integrated double block valves.
As specified in FM 7400 standard, a valve proving system must be leak-tight with a leak rate no greater than
24in
3
/hr (0.0138 ft
3
/hr, 393 cm
3
/hr)
In certain cases, local codes may require the factoring of the burner capacity in order to derive the leak rate.
For example, it could be specified that the leakage shall not be greater than 0.01% of burner capacity.
Example of Test Times Calculation:
Assume a valve proving installation with an integrated valve train consisting of total volume of 0.018 ft
3
, and
an inlet pressure of 0.5 psi and a permissible leakage rate of 0.04 ft
3
/hr for upstream valve and 0.035 ft
3
/hr for
WARNING: It is the responsibility of the installing and operating personnel to ensure that the valve prov-
ing system is properly installed and configured. The appropriate permissible leakage rate information
should be used when setting up a valve proving system. Please consult the burner manufacturer and/or
applicable codes, ordinances, and regulations.