NBN EN 334:2005

This document specifies constructional and functional requirements, regulator sizing, testing, documentation and marking of gas pressure regulators used in the pressure regulating stations:
- for inlet pressures up to 100 bar and nominal diameters up to DN 400;
- for an operating temperature range from 20 °C to +60 °C,
which operate with fuel gases of the 1st and 2nd family in accordance with EN 437 in transmission and distribution networks and also in commercial and industrial installations.
"Gas pressure regulators" hereafter will be called "regulators" except in the titles.
The harmonised part of this document deals with standard gas pressure regulators used in pressure regulating stations complying with EN 12186 or EN 12279. For gas pressure regulators integral strength type when used in pressure regulating stations complying with EN 12186 or EN 12279, Annex ZA lists all applicable Essential Requirements except the external resistance to environmental conditions where corrosion occurs.
This document considers the following classes of regulators:
- class 1: operating temperature range from 10 °C to 60 °C;
- class 2: operating temperature range from 20 °C to 60 °C.
This document applies to regulators which use the pipeline gas as a source of control energy unassisted by any external power source.
The regulator may incorporate a creep (venting) relief device, complying with the requirements in Annex F.
The regulators complying with the requirements of this document may be declared as "in compliance with EN 334" and bear the mark "EN 334".
This document does not apply to:
- regulators upstream from/on/in domestic gas consuming appliances which are installed downstream of domestic gas meters;
- regulators in accordance with prEN xxxxxx (WI 00235003 under preparation by CEN/TC 235) that comply with both of the following characteristics:
- volumetric flow rate £ 200 m3/h at normal conditions;
- inlet pressure £ 5 bar;
- regulators for which a specif