prEN 17691-1

Components for BAC control loops - Valve and actuator assemblies - Part 1: Water-based HVAC applications prEN 17691-1

Publication date:   Oct 17, 2024

Scope

This document specifies requirements and test methods of valve-actuator assemblies in individual zone control of water-based HVAC applications.
Control valves of nominal diameter larger than DN50 are currently not covered by this document.
Within the scope are pressure independent and pressure dependent control valve-actuator assemblies of relevant categories: 2-port, 3-port and 6-port valves (if they incorporate a control valve function).
Where a certain control loop as a combination of controller and valve-actuator assembly was assessed under EN 15500-1:2017, this European Standard allows the assessment of the performance of combinations of that controller with different valve-actuator assemblies. The tests in this document ensure that valve/actuator assemblies, as components of control loops, can be replaced with products that provide comparable or better performance.
In hydronic system, valve-actuator assembly is a component of control loop that controls water flow rate according to the application control demand. The common Formula (1) describing the flow rate where whole hydronic system itself has an influence on actual flow rate as differential pressure across control valve-actuator assembly typically varies during operation.

Q=k_v . √((∆p_v)/(∆p_1 bar ))

where
Q [m3/h] water flow
kv [m3/h] flow coefficient of the valve
Δpv [bar] differential pressure across the valve
Δp1bar [bar] 1 bar differential pressure