ISO 21904-4:2020 PDF
Health and safety in welding and allied processes — Equipment for capture and separation of welding fume — Part 4: Determination of the minimum air volume flow rate of capture devices
Health and safety in welding and allied processes — Equipment for capture and separation of welding fume — Part 4: Determination of the minimum air volume flow rate of capture devices
- Статус документа:
- Действующий
- Формат:
- Электронный (PDF)
- Количество страниц:
- 10
- Дата публикации:
- 21 февраля 2020 г.
- Издание:
- ISO IS 21904 edition 1 version 1
- ICS:
- 13.100
This document specifies two methods for establishing the minimum air volume flow rate. One method is dedicated for use with captor hoods, nozzles and slot nozzles with a ratio of slot length to hose diameter of 8:1 or less. The other method is dedicated for use with on-gun extraction devices. These methods are not applicable to down draught tables.
Abstract
Overview - ISO 21904-4:2020 (welding fume capture devices)
ISO 21904-4:2020 specifies test methods to determine the minimum air volume flow rate required for effective capture of welding fume from local extraction devices. It defines two dedicated procedures:
- one for captor hoods, nozzles and slot nozzles (slot length to hose diameter ratio ≤ 8:1), and
- one for on-torch / on-gun extraction devices.
The standard focuses on guaranteeing the suction field size and induced air velocity needed to capture welding emissions. It excludes down-draft tables and permits use of measured testing or numerical simulation (CFD) where stated.
Key topics and technical requirements
- Test principles: Establish the minimum volumetric flow that produces the required induced velocity and capture area at a specified measurement plane relative to the extraction duct diameter (D). Measurement plane location and capture-field dimensions are prescribed.
- Measurement setup: Position devices free-standing, avoid draughts (
Технические детали
- Технический комитет
- ISO/TC 44/SC 9 - Health and safety
- SKU
- ISO 21904-4:2020
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