3D Printing • ATEX Zone 20/21 • Oil Inerting
Delfin MTL 451 1/2D INERT
Compact oil inerting vacuum with ATEX II 1/2D certification for the safe collection of self-igniting metal powder from 3D printing processes. Zone 20 internal, Zone 21 external. HEPA H14. IECEx.
- ATEX II 1/2D — Zone 20 internal, Zone 21 external • IECEx Da/Db
- HEPA H14 — 99.995 % at MPPS (EN 1822)
- Oil inerting — neutralises reactive powder before emptying
- TEFC motor 1.1 kW — 215 m³/h, 2,250 mmH₂O
- AISI 304 container — INERT tank 10 L oil / 15 L total
- 74 dB(A) • 52 kg • compact and mobile on wheels
- Tested to EN 17348 • EN IEC 62784:2018 • EN ISO 80079-36:2016
What is the Delfin MTL 451 1/2D INERT?
The MTL 451 1/2D INERT is a compact, mobile industrial vacuum cleaner from Delfin, developed specifically for the collection of reactive and self-igniting metal powders generated by metal 3D printing processes, including laser powder bed fusion (LPBF), binder jetting and direct metal laser sintering (DMLS). Its defining feature is the oil inerting system, which neutralises collected powder directly inside the container so that it cannot react, ignite or explode when the container is emptied or handled.
The machine carries ATEX II 1/2D certification issued by a notified body, attested for use in Zone 20 internally (inside the machine) and Zone 21 externally (the surrounding environment). It also holds IECEx certification, which means it meets the international requirements for explosion-protected equipment — relevant for companies exporting products or demonstrating compliance to international buyers. Performance testing has been carried out in accordance with EN 17348:2022, the harmonised standard for industrial vacuums for hazardous dust.
The TEFC motor (Totally Enclosed Fan Cooled) delivers 1.1 kW and cools itself without drawing ambient air into the motor housing. This is critical in an ATEX context: explosive atmospheres must never come into contact with hot motor surfaces or live electrical components. Airflow is 215 m³/h at a maximum vacuum of 2,250 mmH₂O.
Filtration system and INERT technology
The filtration system is a two-stage design. The primary filter is a Star/Tasche type in antistatic polyester class ANT M with a filter area of 20,000 cm² and a diameter of 420 mm. It is cleaned manually via the integrated shaking mechanism, and a filter indicator warns when the filter requires attention. The second stage is a HEPA H14 filter with a filter area of 11,000 cm², retaining at least 99.995 % of all particles at MPPS.
The INERT container is manufactured in AISI 304 stainless steel and holds 10 L of inerting oil. The combined volume of oil plus vacuumed material must not exceed 15 L. When reactive metal powder is drawn into the container, it mixes with the oil and is neutralised before it can react with oxygen or moisture. The container seals tightly so it can be emptied safely without dispersing dry powder.
Technical specifications
| Parameter | Value |
|---|---|
| ATEX marking | II 1/2D Ex h tb IIIC T80°C (Int) / T95°C (ext) Da/Db |
| ATEX zone | Zone 20 internal, Zone 21 external |
| EX category | CE EX 21 1/2D • IECEx Da/Db |
| Voltage | 115/230 V • 50/60 Hz • single phase • 8 A |
| Power | 1.1 kW |
| Motor type | TEFC (Totally Enclosed Fan Cooled) |
| Airflow | 215 m³/h |
| Vacuum pressure (max.) | 2,250 mmH₂O |
| Suction inlet | Ø50 mm |
| Primary filter | Star/Tasche polyester ANT M • 20,000 cm² • Ø420 mm |
| Filter cleaning | Manual shaking mechanism • filter indicator incl. |
| HEPA filter | H14 • 99.995 % at MPPS • 11,000 cm² |
| INERT capacity (oil) | 10 L |
| INERT capacity (oil + material) | 15 L (max.)* |
| Container | AISI 304 stainless steel |
| Dimensions | 61 × 66 × 133 cm (H) |
| Weight | 52 kg |
| Noise level | 74 dB(A) (EN ISO 3744) |
| Accessory kit | TA.1057.0000 — included |
| Standards | EN 17348 • EN IEC 62784:2018 • EN ISO 80079-36:2016 |
* Variable based on the vacuumed material characteristics.
Accessories and options
The MTL 451 1/2D INERT is supplied with accessory kit TA.1057.0000, which includes the necessary hose equipment and suction adapters for connection to 3D printers and CNC machines. All accessories have been tested and approved for ATEX use. The ATEX version with IECEx certification carries the product code MTL451INERTZ21-001 (MTL 451 EX 1/2D — IECEx Da/Db 1BL 45L DT DS X H INERT).
Questions and answers
Many metal powders used in 3D printing — including aluminium, titanium and magnesium — are pyrophoric: they can self-ignite on contact with oxygen or moisture when the particles are sufficiently fine. Oil inerting works by coating the powder particles with inerting oil inside the container, cutting them off from oxygen before they can react. This makes emptying and downstream handling significantly safer, as the collected material is no longer in a reactive state.
Category 1/2D covers both Zone 20 (explosive dust atmosphere continuously or frequently present) internally and Zone 21 (periodically present) externally — the strictest classification for vacuums with hazardous internal zones such as the INERT container interior. Category 3D covers only Zone 22 (rarely and briefly present) externally, and is used for machines with a lower risk profile. The MTL 451 is II 1/2D and is suited to the most demanding environments.
IECEx is the international certification scheme for explosion-protected equipment under IEC (International Electrotechnical Commission). While ATEX is an EU directive, IECEx is recognised globally — including in Australia, South Africa and many Asian markets. An IECEx certificate supplements the ATEX mark and documents that the machine meets identical technical requirements, but is issued by an internationally accredited test institute. This is relevant for companies with international partners or subsidiaries outside the EU.
