Valve operation and diagnosis

A non-transitory, tangible computer readable medium storing a computer program product for diagnosing of a valve assembly of a gas-fired installation, which valve assembly includes a plurality of valve members serially arranged along a flow channel of the valve assembly connecting at least one inlet and at least one outlet of the valve assembly, the computer program product comprising instructions executable by a processor to:

• during an operation of the gas-fired installation, control at least one flow sensor to measure a flow of a fluid through the flow channel of the valve assembly,
• close at least one of the serially arranged valve members of the valve assembly such that fluid flow is prevented through the flow channel,
• open at least one of the valve members of the valve assembly to permit a fluid flow from an upstream side of the at least one valve member to a downstream side of the at least one valve member,
• control the at least one flow sensor to measure at least one signal related to fluid flow, wherein the at least one signal comprises a pulse,
• apply quasi-integration to the at least one signal to determine at least one quantity characterizing the at least one signal,
• compare the at least one quantity to at least one threshold value, and
• determine that the at least one quantity exceeds the at least one threshold value, and in response to such determination, detect a leakage flow caused by at least one faulted valve member of the plurality of valve members,
• wherein the at least one sensor is configured to (a) detect the leakage flow having a flow velocity between 0.1 m/s and 5 m/s, and (b) measure normal operational flow velocities through the flow channel of the gas-fired installation in operation.

A valve assembly of a gas-fired installation, the valve assembly comprising:

• an inlet and an outlet,
• a flow channel connecting the inlet to the outlet,
• a plurality of valve members serially arranged along a flow channel of the valve assembly,
• at least one actuator configured to open at least one of the valve members, and
• at least one flow sensor arranged either:
• (i) between the inlet of the valve assembly and the valve member closest to the inlet, or (ii) between the outlet of the valve assembly and the valve member that is closest to the outlet,
• wherein the at least one flow sensor is configured to (a) detect a leakage flow having a flow velocity between 0.1 m/s and 5 m/s, caused by at least one faulted valve member of the plurality of valve members and (b) measure normal operational flow velocities through the flow channel of the gas-fired installation in operation.