UNI EN 88-2 : 2008

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
  3.1 Pressure regulator
  3.2 Components
  3.3 Safety shut-off devices
  3.4 Control variables
      3.4.1 Reference values
      3.4.2 Variables in the controlling process
      3.4.3 Possible values of all variables
      3.4.4 Terms pertinent to the controlled variable
  3.5 Operating features in stable conditions
  3.6 Features pertinent to accuracy
  3.7 Features pertinent to lock-up behaviour
  3.8 Further functional terminology
      3.8.1 Pressures pertinent to design of gas
            pressure regulator
      3.8.2 nominal pressure
      3.8.3 operating temperature range temperature
            range at which the pressure regulator
            components and fixtures are capable of
            operating continuously
4 Classification
5 Units of measurement and test conditions
  5.1 Units of measurement
  5.2 Test conditions
6 Construction requirements
  6.1 General
  6.2 Construction
      6.2.1 General
      6.2.2 Breather holes
      6.2.3 External visual Indication of the position
            of the closure member
      6.2.4 Parts transmitting actuating forces
      6.2.5 Pressure adjustment
  6.3 Materials
      6.3.1 General
      6.3.2 Springs
      6.3.3 Requirements for elastomers (including
            vulcanized rubbers)
  6.4 Gas connections
      6.4.1 General
      6.4.2 Connection sizes
      6.4.3 Threads
      6.4.4 Pressure test nipples (applicable only
            for outlet connections operating at <=
            500 mbar)
7 Performance requirements
  7.1 General
  7.2 Strength of housings
      7.2.1 Requirement
      7.2.2 Performance test
  7.3 External and internal leak tightness
  7.4 Torsion and bending
  7.5 Control classification
      7.5.1 General
      7.5.2 Control classifications for pressure regulators
      7.5.3 Safety shut-off device accuracy group
            for over-pressure
  7.6 Safety devices
      7.6.1 Over-pressure safety shut-off device
      7.6.2 Under-pressure safety shut-off devices
      7.6.3 Bypass
      7.6.4 Response time
  7.7 Durability of performance
      7.7.1 Pressure regulator
      7.7.2 Safety slam-shut device
8 Marking, installation and operating instructions
  8.1 Marking
  8.2 Installation, operating and servicing instructions
  8.3 Warning notice
Annex A (informative) - Main components for direct
                        acting and pilot controlled
                        pressure regulators
  A.1 Main components of a pressure regulator
  A.2 Main components of a gas safety shut-off device
Annex B (informative) - Use of ISO 7-1 and EN ISO 228-1
                        threads for gas connections
Annex C (normative) - Performance test methods
  C.1 General
  C.2 Apparatus and test rig
  C.3 Performance tests under stable conditions
      C.3.1 General
      C.3.2 Determination of a performance curve
      C.3.3 Determination of the lock-up pressure
      C.3.4 Regulator accuracy class
  C.4 Safety shut-off device accuracy group
      C.4.1 General conditions and apparatus
      C.4.2 Test at ambient temperature
      C.4.3 Test at the limit temperatures between
            0 degree C and 60 degree C
      C.4.4 Verification of the upper limit of the
            highest set range
      C.4.5 Response time
  C.5 Durability of performance
      C.5.1 General
      C.5.2 Pressure regulator
      C.5.3 Safety shut-off devices
Annex ZA (informative) - Relationship between this
                         European Standard and the Essential
                         Requirements of EU Directive
                         90/396/EEC
Bibliography