NS EN 88 : 1991 AMD 1 1996

Cooperating organizations
National foreword
Foreword
1. General
1.1 Object and field of application
1.2 References
1.3 Definitions
1.4 Classification
1.5 Measuring ratio
2. Construction requirements
2.1 General
2.2 Materials
2.3 Connections
2.4 Seals for glands for moving parts
2.5 Pressure test nipples
3. Performance requirements
3.1 General
3.2 Putting the governor out of action
3.3 External leak-tightness
3.4 Torsion and bending
3.5 Durability
3.6 Governor performance
3.7 text deleted
3.8 Durability of performance
3.9 Lock-up pressure
4. Test methods
4.1 General
4.2 Putting the governor out of action
4.3 External leak-tightness
4.4 Torsion and bending
4.5 Durability
4.6 Governor performance
4.7 text deleted
4.8 Durability of performance
4.9 Lock-up pressure
5. Marking, installation and operating instructions
5.1 Marking
5.2 Installation, operating and servicing instructions
5.3 Warning notice
Annexes
A. Characteristics of combustible gases
B. Typical governors and governor parts
C. Use of ISO 7-1: 1982 and ISO 228-1: 1982 threads
      for gas connections
D. Leak-tightness test - volumetric method
E. Leak-tightness test - pressure loss method
F. Conversion of pressure loss into leakage rate
G. Summary of requirements and test conditions
Tables
1. Connection sizes
2. Maximum external leakage rates
3. Torque and bending moment
4. Gas pressure at inlet to the governor
5. Outlet pressure variation from the outlet setting
      pressure
6. Sequence of testing
7. Tightening torque for flange bolts to ISO 7005-2:
      1988
Figures
1. Arrangement for torsion test
2. Arrangement for bending test
3. Paint scratch test apparatus
4. Governor performance test rig
5. Graph of performance using inlet pressure variation
6. Graph of performance using flow rate variation
7. Types of constant pressure governor (diagrammatic)
8. Apparatus for testing leak-tightness (volumetric
      method)
9. Apparatus for testing leak-tightness (pressure loss
      method)

Describes the safety, constructional and performance requirements for pressure governors for use with gas appliances. Gives test procedures for evaluating these and information necessary for the purchaser and user. Applies to pressure governors for gas-burning appliances of connection size up to and including DN 50 and that may be used and tested independently of these appliances. Suitable for fuel gases of the 1st, 2nd and 3rd families. Does not cover: governors connected to mains and governors for gas appliances installed out-of-doors.