EN 16257:2012

Overview

EN 16257:2012 - "Tanks for the transport of dangerous goods - Service equipment - Footvalve sizes other than 100 mm dia (nom)" is a CEN European Standard that specifies performance requirements, critical dimensions and test methods for pressure balanced and non-pressure balanced footvalves used for loading and unloading tank vehicles and containers. The standard applies to footvalves with nominal diameters other than 100 mm and is targeted at tanks carrying Class 3 (flammable) liquids under ADR conditions (vapour pressure ≤ 110 kPa at 50 °C, non‑toxic and non‑corrosive), including petrol. Footvalves covered by EN 16257 are not suitable where product velocity exceeds 5 m/s.

Key topics

• Scope & applicability: Covers non‑pressure and pressure balanced footvalves intended for loading/unloading of road tankers and vehicle-mounted containers transporting Class 3 flammable liquids.
• Performance requirements: Self‑closing containment function, actuation behavior (non‑pressure balanced may self‑open under hydraulic force; pressure balanced requires external actuation).
• Critical dimensions: Tank mounting flange, run‑off flange (circular and square) and preferred size combinations - detailed in Annexes A, B, C and F.
• Break‑away security: Design to ensure external housing breaks away on impact while keeping the internal sealing mechanism intact; impact energy limits specified:
  • Nominal diameter < 100 mm: ≤ 1 kJ
  • Nominal diameter > 100 mm: impact energy limit = (dt / 100)² kJ (dt in mm)
• Tests & verification: Test procedures reference EN 13308 and EN 13316 for detailed testing of non‑pressure and pressure balanced types; Annexes D and E describe break‑away test positions and apparatus.
• Installation, marking & maintenance: Marking, operating and maintenance recommendations required; electrical resistance, materials, temperature range and strainers are covered by cross‑reference to EN 13308/EN 13316.

Applications

EN 16257 is used by:

• Tank and service equipment manufacturers designing footvalves for road tankers, rail tanks and vehicle tanks.
• Tank designers and OEMs selecting appropriate valve sizes and flange interfaces for bottom loading/unloading.
• Operators and fleet managers ensuring equipment meets safety and regulatory requirements for Class 3 liquids.
• Test laboratories and conformity assessors performing break‑away, pressure and functional tests.
• Regulators and inspectors verifying compliance with ADR and European national implementations.

Practical use cases include emergency/internal security valves, bottom loading/outlet control, and retrofitting service equipment on tanks where nominal footvalve sizes differ from the 100 mm nominal standard.

Related standards

• EN 13308 (non‑pressure balanced footvalve)
• EN 13316 (pressure balanced footvalve)
• EN 13081 / EN 13082 / EN 13083 (vapour/adaptor equipment)
• EN 13314 / EN 13315 / EN 13317 (other service equipment)
• EN 14595 / EN 14596 (breather and relief valves)
• ADR, CEN/TR 15120, EN 12266, ISO 2859 (referenced guidance and test standards)

Keywords: EN 16257, footvalve sizes other than 100 mm, tanks for transport of dangerous goods, pressure balanced footvalve, non-pressure balanced footvalve, ADR Class 3, break-away test, service equipment.