BS EN 334 : 2005

Foreword
1 Scope
2 Normative references
3 Terms, definitions and symbols
  3.1 General terms and definitions of types of gas pressure
      regulators
  3.2 Terms and definitions of components of gas pressure
      regulators
  3.3 Terms, symbols and definitions of components of
      functional performance
  3.4 Terms, symbols and definitions related to design
      and tests
4 Construction requirements
  4.1 Basic requirements
  4.2 Materials
  4.3 Strength of housings
5 Functional requirements
  5.1 General
  5.2 Shell strength, external tightness and internal sealing
  5.3 Control classifications
  5.4 Final visual inspection
  5.5 Fail-close conditions
6 Gas pressure regulator sizing
  6.1 Flow behaviour
  6.2 Sizing equations for the calculation of volumetric
      flow rates of a gas pressure regulator with its
      control member in its mechanically fully open position
  6.3 Calculation of the maximum accuracy flow rate
  6.4 Inherent flow characteristics
  6.5 Calculation of volumetric flow rates for partially
      open gas pressure regulators
  6.6 Flow coefficient
7 Testing
  7.1 General
  7.2 Tests
  7.3 Type test
  7.4 Selection of test samples
  7.5 Routine tests
  7.6 Production surveillance
  7.7 Test and verification methods
8 Documentation
  8.1 Documentation related to type test
  8.2 Documentation related to the routine tests
  8.3 Documentation related to production surveillance
      in accordance with 7.6
9 Marking
  9.1 General requirements
  9.2 Markings for the various connections
  9.3 Marking of integrated safety devices
Annex A (informative) - 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
      A.1 General
      A.2 Test methods
      A.3 Determination of flow coefficients for larger
          capacity regulators
Annex B (informative) - Inspection certificate
Annex C (informative) - Acceptance test
Annex D (informative) - Compliance evaluation
      D.1 General
      D.2 Introduction
      D.3 Procedure
      D.4 Manufacturer's compliance evaluation
      D.5 Issue of the certificate of compliance
Annex E (informative) - Seat leakage (alternative requirement)
Annex F (normative) - Creep (venting) relief device
      F.1 General
      F.2 Terms and definitions
      F.3 Requirements
      F.4 Testing
      F.5 Type test
      F.6 Routine tests
      F.7 Documentation
      F.8 Marking
Annex G (informative) - Order specification
      G.1 General
      G.2 Minimum specifications
      G.3 Optional specifications
Annex H (normative) - Materials
      H.1 Steel materials for pressure containing parts and
          inner metallic partition walls
      H.2 Metallic materials different from steel materials
          for pressure containing parts and inner metallic
          partition walls
      H.3 Materials for fixtures, integral process and
          sensing lines, connectors and fasteners
Annex I (informative) - Glossary
Annex ZA (informative) - Relationship between this European
         Standard and the Essential Requirements of EU
         Directive 97/23/EC
Bibliography

Describes constructional, functional, testing and marking requirements, sizing and documentation of gas pressure regulators used in the pressure regulating stations in accordance with EN 12186 or EN 12279.