BS EN 12078:1998

Foreword
1 Scope
2 Normative references
3 Definitions
4 Units of measurement
5 Construction requirements
    5.1 General
    5.2 Materials
    5.3 Connections
    5.4 Seals for glands for moving parts
    5.5 Pressure test nipples
6 Performance requirements
    6.1 General
    6.2 External leak-tightness
    6.3 Torsion and bending
    6.4 Durability
    6.5 Zero governor performance
    6.6 Endurance
    6.7 Lock-up pressure
    6.8 Response time
7 Test methods
    7.1 Mounting position
    7.2 Test conditions
    7.3 External leak-tightness
    7.4 Torsion and bending
    7.5 Durability
    7.6 Zero governor performance test
    7.7 Pressure drop (fully open)
    7.8 Endurance
    7.9 Lock-up pressure
    7.10 Dynamic response test
8 Marking, installation and operating instructions
    8.1 Marking
    8.2 Installation, operating and servicing instructions
    8.3 Warning notice
Annex ZA (informative) Clauses of this European Standard
addressing essential requirements or other provisions of
EU Directives
Table 1 Connection sizes
Table 2 Maximum external leakage rates
Table 3 Torque and bending moment
Table 4 Gas pressure at inlet to the zero governor
Figure 1 Arrangement for torsion test
Figure 2 Arrangement for bending moment test
Figure 3 Paint scratch test apparatus
Figure 4 Performance test rig
Figure 5 Characteristics of p2 as p1 varies
Figure 6 Characteristics of p2 as q varies

Defines the safety constructional and performance requirements for zero pressure governors, known as zero governors, to be used with gas appliances. In addition, it supplies the test methods for evaluation of these requirements and information necessary for the purchaser and user. Applicable to zero governors for gas-burning appliances used and tested independently of these appliances.