BS ISO 4126-10:2010

Safety devices for protection against excessive pressure - Sizing of safety valves for gas/liquid two-phase flow

Published:

31 Dec 2010

•

Withdrawn:

4 Apr 2024

1 Scope

This part of ISO 4126 specifies the sizing of safety valves for gas/liquid two-phase flow in pressurized systems such as reactors, storage tanks, columns, heat exchangers, piping systems or transportation tanks/containers. The possible fluid states at the safety valve inlet that can result in two-phase flow are given in Table 1.

NOTE The expression “safety valve” is a synonym for valves as described in ISO 4126‑1, ISO 4126‑4 and ISO 4126‑5.

Table 1 — Possible fluid state at the inlet of the safety valve that can result in two-phase flow

Fluid state at valve inlet	Cases	Examples
liquid	subcooled (possibly flashing in the safety valve) saturated with dissolved gas	cold water boiling water CO₂/water
gas/vapour	near saturated vapour (possibly condensing in the safety valve)	steam
gas/liquid	vapour/liquid non-evaporating liquid and non-condensable gas (constant quality) gas/liquid mixture, when gas is desorbed or produced	steam/water air/water

Product Details

Descriptors

Pressure control

Dimensions

Liquids

Heat exchangers

Valves

Safety valves

Flow control

Safety devices

Pressure equipment

Mathematical calculations

Tanks (containers)

Gases

Pipework systems

ICS Codes

13.240 Protection against excessive pressure

23.060.40 Pressure regulators

Committee

PSE/18/6

International relationships

Identical to:

ISO 4126-10:2010

ISBN

978 0 580 57618 8

Publisher

BSI