KST – KROMSCHRÖDER SYSTEM TECHNOLOGY
22.214.171.124.4 Valve proving system
Automatic shut-off valves controlling capacities greater than 1200 kW [see 1] shall be equipped with a valve proving system. If this is applicable, then the valve proving system shall comply with EN 1643 or give an equivalent level of safety.
The signal of a leaking valve2) from the valve proving system shall stop the current start-up when the test takes place during start up or prevent the next start-up when the test takes place after shut down.
This function shall meet the requirements of a protective system according to 5.7.2 and 5.7.3.
The following chapters are printed with the permission of the DIN Deutsches Institut für Normung e.V. (German Institute for Standardization). For the implementation of the DIN Standard, the version with the most recent issue date is deemed authoritative. This is available from Beuth Verlag GmbH, Burggrafenstrasse 6, 10787 Berlin, Germany.
Our note on this Standard:
1) In the case of multiple burner systems with a central main shut-off valve, the capacity is defined on the basis of the flow through the first valve. This is equal to the sum of the flow through the downstream valves.
2) Leakage rate < 0.1% of the maximum flow rate (Qb) are permitted by analogy with EN 1643.