EN 593 butterfly valves: specification guide

Define the valve pattern and interface

State wafer, lugged or flanged construction, DN, PN, flange standard, face-to-face series and required bore. Check disc clearance inside the mating pipe, gasket and lining.

For replacement work, verify dimensions from approved drawings and site measurements. A matching DN and PN do not guarantee dimensional compatibility.

State pressure, temperature and direction

Provide design pressure and temperature, differential pressure in both directions, flow direction and vacuum conditions. Confirm the manufacturer rating for the offered body, disc and seat combination.

Identify dead-end service for lugged valves and any reduced rating. Define installation orientation and shaft loading.

Select materials as a system

Specify body, disc, shaft, seat, bearings, fasteners and coating. Check fluid chemistry, solids, velocity, corrosion and elastomer limits.

For coated valves, define surface preparation, thickness, holiday testing and repair. Avoid assuming one water-service coating fits every process.

Specify actuation and acceptance tests

Provide maximum differential pressure, travel time, fail action, power and controls. Require torque data for the final configuration.

Name shell and seat test pressure, duration, direction and leakage criterion. Add dimensional, coating and functional records to the final dossier.

Checklist

• valve pattern
• DN, PN and flange standard
• face-to-face series
• disc clearance
• bidirectional or dead-end duty
• materials and coating
• seat grade
• torque and actuator data
• test standard and leakage
• final drawings and records

Primary references

• European and British standards catalogue, BSI
• ISO 5208:2015, Industrial valves pressure testing
• ISO 9001, Quality management systems