ČSN EN 1776
Zařízení pro zásobování plynem - Systémy měření plynu - Funkční požadavky

ČSN EN 1776 (38 6435)

This document specifies functional requirements for the design, construction, testing, commissioning/decommissioning, operation, maintenance and, where appropriate, calibration, together with suitable documented provisions for all new gas measuring systems and any major changes of existing systems.
This document also specifies accuracy classes of measuring systems and thresholds applicable to these classes. Demonstration of compliance is achieved through the selection, installation and operation of appropriate measurement instruments, together with suitable documented provisions for calculations. Examples of demonstration of compliance are provided for each accuracy class; however, they are not prescriptive solutions.
This document is applicable for gases of the 2nd family as classified in EN 437. It is also applicable for treated non-conventional combustible gases complying with EN 437 and for which a detailed technical evaluation of the functional requirements (such as injected biomethane) is performed ensuring there are no other constituents or properties of the gases that can affect the metrological and physical integrity of the measuring systems. This version mentions technical topics to consider when hydrogen and natural gas / hydrogen blends flow through the measuring systems. Blends with a hydrogen content between 20mol% and 98 mol% are not considered by this standard. This document applies to hydrogen with a purity as specified in CEN/TS 17977 for rededicated natural gas systems.
This document can also be used as a guideline for measuring systems for other gases e.g. gaseous CO2 for CCUS.
This document does not apply to for raw or sour gases.
This document does not apply to for gas measurement in CNG filling stations.
This document gives guidelines when designing, installing and operating gas meters with additional functionalities (smart gas meters).
Communication protocols and interfaces for gas meters and remote reading of gas meters are outside the scope of this document and are covered by the appropriate parts of the EN 13757 series. which provide a number of protocols for meter communications. Supervisory control and data acquisition protocols (SCADA) are also not covered by this document.
Unless otherwise specified all pressures used in this document are gauge pressures.
For associated pressure regulating systems the requirements of EN 12186 and/or EN 12279 apply.
For requirements on design, housing, lay-out, materials for components, construction, ventilation, venting and overall safety of gas measuring systems within the scope of this document, the EN 15001 series, EN 12186, EN 12279 and/or EN 1775 apply additionally, where relevant.