EN 334:2005

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Gas pressure regulators for inlet pressures up to 100 barRegulatorji tlaka plina za vstopne tlake do 100 barAppareils de régulation de pression de gaz (régulateurs) pour des pressions amont jusqu'a 100 barGas-Druckregelgeräte für Eingangsdrücke bis 100 barTa slovenski standard je istoveten z:EN 334:2005SIST EN 334:2005en,fr,de23.060.40ICS:SIST EN 334:2000/A1:2003SIST EN 334:20001DGRPHãþDSLOVENSKI
STANDARDSIST EN 334:200501-junij-2005

EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 334
March 2005 ICS 23.060.40 Supersedes EN 334:1999 English version
Gas pressure regulators for inlet pressures up to 100 bar
Appareils de régulation de pression de gaz (régulateurs) pour des pressions amont jusqu'à 100 bar
Gas-Druckregelgeräte für Eingangsdrücke bis 100 bar This European Standard was approved by CEN on 23 December 2004.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
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B-1050 Brussels © 2005 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 334:2005: E

Alternative methods for the determination of the accuracy class, the lock-up pressure class, the maximum accuracy flow rate, the flow coefficients and the verification of the hysteresis band.62 A.1 General.62 A.2 Test methods.62 A.2.1 Direct acting gas pressure regulator.62 A.2.2 Pilot controlled gas pressure regulators.63 A.3 Determination of flow coefficients for larger capacity regulators.64 Annex B (informative)
Inspection certificate.70 Annex C (informative)
Acceptance test.72 Annex D (informative)
Compliance evaluation).73 D.1 General.73 D.2 Introduction.73 D.3 Procedure.73 D.4 Manufacturer’s compliance evaluation.74 D.5 Issue of the certificate of compliance.74 Annex E (informative)
Seat leakage.75 Annex F (normative)
Creep (venting) relief device.76 F.1 General.76

Order specification.78 G.1 General.78 G.2 Minimum specifications.78 G.2.1 Details of construction.78 G.2.2 Dimensions.78 G.2.3 Performance.78 G.3 Optional specifications.79 Annex H (normative)
Materials.80 H.1 Steel materials for pressure containing parts and inner metallic partition walls.80 H.2 Metallic materials different from steel materials for pressure containing parts and inner metallic partition walls.86 H.3 Materials for fixtures, integral process and sensing lines, connectors and fasteners.91 Annex ZA (informative)
Relationship between this European Standard and the Essential Requirements of EU Directive 97/23/EC.94 Bibliography.95

Key 1 Setting element 6 Sensing line 2 Detector element 7 Regulator body 3 Breather/exhaust line 8 Valve seats 4 Actuator 9 Seat ring 5 Casing of actuator 10 Control member 1 + 2 = Controller Figure 1 — Example of a direct acting regulator 3.1.1.2 pilot controlled gas pressure regulator (indirect acting) regulator in which the net force required to move the control member is supplied by a pilot (see example in Figure 2)

Key 1 Fixture 6 Regulator body 2 Pilot 7 Valve seats 3 Actuator 8 Seat ring 4 Casing of actuator 9 Control member 5 Sensing/process line 10 Motorization chamber Figure 2 — Example of a pilot controlled regulator 3.1.1.3 monitor second regulator normally installed in series with an active regulator which has the task of maintaining the controlled variable within allowable limits in the event of its value exceeds a pre-established value (e.g. in the event of opening of the active regulator due to a failure, etc.) 3.1.1.4 series of regulators regulators with the same design concept but differing only in size 3.1.1.5 fail open regulator regulator whose control member automatically tends to open when the main diaphragm fails or when the energy required to move the control member fails NOTE The definition in this clause is based on typical control failure modes. 3.1.1.6 fail close regulator regulator whose control member automatically tends to close when the main diaphragm fails or when the energy required to move the control member fails NOTE The definition in this clause is based on typical control failure modes. 3.1.1.7 integral strength regulator regulator in which the pressure containing parts have a design pressure equal to the maximum allowable pressure PS

nominal inlet diameter nominal size DN of the inlet connection in accordance with EN ISO 6708 3.1.1.10 nominal outlet diameter nominal size DN of the outlet connection in accordance with EN ISO 6708 3.1.2 main components parts including normally: control member, regulator body, actuator, casing of actuator, controller, pilot (only in pilot controlled regulators) NOTE The regulator might include additional devices such as a shut-off device, a monitor, a relief valve and other fixtures. The Figures 1 and 2 serve as examples. 3.1.2.1 control member movable part of the regulator which is positioned in the flow path to restrict the flow through the regulator NOTE A control member may be a plug, ball, disk, vane, gate, diaphragm, etc. 3.1.2.2 body main pressure containing envelope which provides the fluid flow passageway and the pipe end connections 3.1.2.3 valve seats corresponding sealing surfaces within a regulator which make full contact only when the control member is in the closed position 3.1.2.4 seat ring part assembled in a component of the regulator to provide a replaceable seat 3.1.2.5 actuator device or mechanism which changes the signal from the controller into a corresponding movement controlling the position of the control member 3.1.2.6 casing of actuator housing of the actuator (which may consist of two chambers under pressure) NOTE When the pressure in each chamber is different from atmospheric pressure, the chamber at the higher pressure is termed the "motorization chamber". 3.1.2.7 controller device which normally includes:  a setting element, normally a spring, to obtain the set value of the controlled variable;

3.2 Control variables 3.2.1 Reference values 3.2.1.1
pressure all pressures specified in this document are static gauge pressures NOTE Pressure is expressed in bar1). 3.2.1.1.1 inlet pressure pu gas pressure at the inlet of the regulator 3.2.1.1.2 outlet pressure pd gas pressure at the outlet of the regulator 3.2.1.1.3 differential pressure ∆p difference between two values of pressure at two different points 3.2.1.1.4 motorization pressure pm gas pressure in the motorization chamber 3.2.1.1.5 pilot feeding pressure pup gas pressure at the inlet of the pilot 3.2.1.2 Flow conditions 3.2.1.2.1 normal conditions absolute pressure pn of 1,013 bar and temperature Tn of 0 °C (273,15 K) NOTE For calculation purposes a value of 273 K is used in this document. 3.2.1.2.2 gas volume volume of gas at normal conditions NOTE Gas volume is expressed in m3.
1) 1 bar = 1 000 mbar = 105 N/m2 = 105 Pa = 10-1 MPa.

Key 1 Max hysteresis band 2 Hysteresis band
Start setting
Measured values Figure 3 — Performance curve (pds constant, pu constant)
Figure 4 — Family of performance curves (pds constant) 3.3.4 family of performance curves set of the performance curves for each value of inlet pressure determined for a given set point (see Figure 4)

3.3.5 Features pertinent to accuracy 3.3.5.1 accuracy average, expressed as a percentage of the set point, of the absolute maximum values of the positive and negative control deviation within the operating range 3.3.5.2 accuracy class AC maximum permissible value of the accuracy 3.3.5.3 inlet pressure range bpu range of the inlet pressure for which the regulator ensures a given accuracy class NOTE The inlet pressure range is characterized by its limit values pumax and pumin. 3.3.5.4 maximum accuracy flow rate lowest value of the maximum volumetric flow rate up to which, for a given set point and within the ambient temperature range specified, a given accuracy class is ensured:  at the lowest inlet pressure (see Figure 5) Qmax,pumin;  at the highest inlet pressure (see Figure 5) Qmax,pumax;  at an intermediate inlet pressure between pumax and pumin (see Figure 5) Qmax,pu 3.3.6 Features pertinent to lock-up behaviour 3.3.6.1 lock-up time tf time taken for the control member to move from an open position to the closed position

= Qmax with the control member at the limit imposed by the mechanical stop Figure 5 — Family of performance curves indicating maximum accuracy flow rates and minimum flow rates (pds constant, stable conditions) 3.3.6.2 lock-up pressure pf pressure that occurs at the measuring point of the controlled variable when the control member is in the closed position NOTE The lock-up pressure corresponds to the outlet pressure at the volumetric flow rate Q = 0 in the performance curve (see Figure 3). It results when the time taken for a change in volumetric flow rate from Q to zero is greater than the lock- up time of the regulator. 3.3.6.3 lock-up pressure class SG maximum permissible positive difference between the actual lock-up pressure and the set point expressed as a percentage of the set point e.g. 100
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=SG dsdsf×PPP (1) 3.3.6.4 minimum flow rate largest value of the minimum volumetric flow rate down to which, for a given set point and within the ambient temperature range specified, stable conditions as per 5.3.3 are obtained:  at the lowest inlet pressure (see Figure 5) Qmin,pumin;  at the highest inlet pressure (see Figure 5) Qmin,pumax;  at an intermediate inlet pressure between pumax and pumin (see Figure 5) Qmin,pu

= SZpumax,pumin,×QQ (2)
Key 1 Lock-up pressure zone Figure 6 — Performance curve indicating lock-up pressure zone (stable condition) 3.4 Further functional terminology 3.4.1 Pressures pertinent to design of gas pressure regulator 3.4.1.1 component operating pressure p gas pressure occurring in any part of a regulator during operation

3.4.1.2 maximum component operating pressure pmax highest operating pressure at which a component of a regulator will continuously operate within specified conditions 3.4.1.3 maximum allowable pressure PS maximum pressure for which the body and its inner metallic partition walls are designed in accordance with the strength requirements in this document 3.4.1.4 test pressure pressure applied to a section of the regulator for a limited period of time in order to prove certain characteristics 3.4.1.5 limit pressure pl pressure at which yielding becomes apparent in any component of the regulator or its fixtures 3.4.1.6 safety factor ratio of the limit pressure pl to the maximum allowable pressure PS applied to:  the regulator body: Sb;  the other pressure containing parts of the regulator: S 3.4.1.7 maximum inlet pressure pumax highest inlet pressure at which the regulator can continuously operate within specified conditions 3.4.1.8 permissible outlet pressure pdmax highest outlet pressure at which the regulator can continuously operate within specified conditions 3.4.1.9 minimum operating differential pressure ∆pmin minimum operating differential pressure between the inlet and outlet pressures below which the regulator will no longer function correctly within specified conditions 3.4.2 nominal pressure numerical designation relating to pressure, which is a convenient round number for reference purposes in accordance with the relevant parts of ISO 7005 (some parts of these documents can be replaced by the equivalent documents when they are available. At the time of writing, this subject is dealt with in EN 1092-1, EN 1092-2, EN 1092-3, EN 1092-4, EN 1759-3, EN 1759-4 and EN 1759-1) NOTE 1 For the specific purpose of this document this term applies to flanges.

o-rings, gaskets, etc.). Jointing
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