Buying a blower for a tank, vessel or manhole in a hazardous area comes down to two questions: is the blower certified for the way your site is classified, and how much air will it actually deliver at the end of the duct? This guide answers both with the regulation text (OSHA 29 CFR 1910.307, 1910.399 and 1910.146), certificate and database records checked on 10 October 2026, and RamFan’s published data for its hazardous-location “xx” blowers, including the EFi150xx. It also compares air-driven (pneumatic) blowers from RamFan, Coppus, Air Systems and Allegro by compressed air use at 80 psi. No prices are quoted.
Quick answer: which hazardous-location blower rating do you need?
- Start from the site’s documented area classification. OSHA requires zone-classified areas, and division-classified areas established after August 13, 2007, to be documented, and the blower has to match the class, the division or zone, and the gas group.
- Class I, Division 1 with an NRTL-listing requirement: buy a blower listed for Class I, Division 1 and your group. The RamFan EFi150xx is not that unit: it is certified for Zone 1 and 2 under ATEX, IECEx, UKEX and INMETRO, and on 10 October 2026 we found no UL or CSA Class/Division listing for it.
- Class I, Zone 1 or Zone 2: OSHA permits flameproof “d” and increased safety “e” equipment in the Class I, Zone 1 locations for which it is approved. The EFi150xx is marked Ex db eb IIB T6 Gb.
- Gas group: the EFi150xx is IIB, which RamFan equates to Class I, Group C. It is not marked IIC.
- Size on ducted airflow, not free air: the EFi150xx moves 4,459 cfm in free air and 3,179 cfm through 15 feet of duct with one 90° turn, about 71% of the free-air figure.
What is the difference between Zone and Class/Division ratings for a blower?
Both systems describe how likely a flammable gas atmosphere is; they slice it differently. OSHA 1910.307 lets a Class I location be classified under either the division system or the zone system, while Class II and Class III locations use divisions only.
| OSHA 1910.399 definition | Ignitable gas or vapor concentrations |
|---|---|
| Class I, Zone 0 | Present continuously, or for long periods of time |
| Class I, Zone 1 | Likely to exist under normal operating conditions, or frequently because of repair, maintenance or leakage |
| Class I, Zone 2 | Not likely in normal operation, and if they occur, only for a short period |
| Class I, Division 1 | May exist under normal operating conditions, or frequently because of repair, maintenance or leakage |
| Class I, Division 2 | Normally confined within closed containers or systems, escaping only through rupture, breakdown or abnormal operation |
Source: 29 CFR 1910.399 definitions, paraphrased; read the full text before classifying a space.
The certificates use a different vocabulary from the nameplate a US buyer expects. The EFi150xx ATEX certificate marking is “II 2 G Ex db eb IIB T6 Gb”. The IECEx certificate names the protection types as flameproof enclosure “db” and increased safety “eb”; RamFan’s own explanation puts mine gases in Group I and other explosive gases in Group II, and defines T6 as a maximum surface temperature of 85°C/185°F. Euramco’s declaration of conformity translates the whole string as “Zone 1, 2” and “T6, non-mining gases up to 85˚C”. A US Class/Division listing would instead read like Class I, Division 1, Group C or D, and a US zone listing carries the “AEx” symbol, as in OSHA’s example “Class I, Zone 0, AEx ia IIC T6.”
When can a Zone 1 ATEX or IECEx blower be used in a US Class I, Division 1 area?
Only if it also holds a US listing for that class, division and group, or if the employer demonstrates that it is safe for the location. A site that requires NRTL-listed Division 1 equipment should not accept an ATEX or IECEx Zone 1 certificate in its place without that review. Under 1910.307(c), equipment in a classified location must be intrinsically safe, approved for the location, or safe for the location. In 1910.399, “approved” means first of all accepted, certified, listed, labeled or otherwise determined to be safe by a nationally recognized testing laboratory, with narrow alternatives for equipment no such laboratory tests and for custom-made equipment; 1910.307 adds that equipment must be approved for the class and for the specific gas or vapor.
Three other provisions decide the edge cases:
- Safe for the location: equipment the employer demonstrates will provide protection from the hazards. That is a site engineering decision, not a purchase specification.
- Zone-classified sites: zone equipment is marked with “AEx”, but equipment the employer demonstrates will provide protection for the gas and zone need not be marked.
- No mixing at the boundary: Class I, Zone 0 or Zone 1 locations may not abut Class I, Division 1 or Division 2 locations.
What the databases showed on 10 October 2026: the IECEx public database lists certificate IECEx UL 13.0062X, issue 7, status Current, issued to Euramco Safety Inc. for the UB20xx, EFi75xx, EFi120xx and EFi150xx portable fans. UL Product iQ returned three Euramco records: UL’s ATEX Directive certification-service record (EXHZ.E482535) and two entries for a thermal-device-protected motor component file (E305448); searches for “RamFan” and “EG8200XX” returned none. CSA Group’s certified product listing returned no records for Euramco, Euramco Safety or RamFan, while a control search for another manufacturer worked. RamFan’s own certification page lists full-unit certifications for ATEX, IECEx, INMETRO, CE and UKCA.
What does the RamFan EFi150xx certification actually cover?
| Item | EFi150xx (EG8200XX 115 V, EG8200XX-230 230 V) |
|---|---|
| ATEX | DEMKO 09 ATEX 0926969X Rev. 7, re-issued 2025-04-21; II 2 G Ex db eb IIB T6 Gb and II 2 G Ex h IIB T6 Gb |
| IECEx | IECEx UL 13.0062X, issue 7, Current; Ex db eb IIB T6 Gb |
| UKEX and INMETRO | UL23UKEX2861X; UL-BR 13.0593X/01, valid to 2031-08-25 |
| Zones | Zone 1, 2 (declaration of conformity) |
| Ambient for T6 | -20 °C to +40 °C (-4°F to +104°F) |
| Ingress protection | IP55 |
| Electrical | 115/230 VAC, 15/8.1 A, 50/60 Hz; 1.5 hp / 1.1 kW |
| Weight and duct | 61 lbs / 28 kg; 16 in / 40 cm duct |
| Not for | Mines susceptible to firedamp |
Sources: RamFan ATEX, IECEx, UKEX and INMETRO certificates; Euramco declaration of conformity; EFi120xx/EFi150xx data sheet and manual.
Two look-alikes to avoid on an order: the EFi150 (part EG8200, no “XX”) is a general-purpose 1.5 hp blower, not the hazardous-location EFi150xx; we list both, so check for the XX. And RamFan’s EFi50xx and EFC series carry a hazardous-location rating on the motor only: the EFi50xx data sheet’s “Class I-II Group D, E, F, G” approval belongs to its motor maker’s UL and CSA files, not to the blower as a unit.
How much airflow do you lose through ducting and bends?
Every foot of duct and every bend adds back-pressure, and RamFan’s manual says back-pressure is typically a function of the length of flexible duct attached to the fan. Free-air cfm is the number on the box; ducted cfm is the number in the tank.
| Model (duct) | Free air | 15 ft, one 90° turn | 15 ft, two turns | 25 ft, one turn | 25 ft, two turns |
|---|---|---|---|---|---|
| UB20xx (8 in, 60 Hz) | 980 cfm | 789 cfm | 666 cfm | 722 cfm | 614 cfm |
| EFi75xx (12 in) | 2,500 cfm | 1,664 cfm | 1,529 cfm | not published | not published |
| EFi150xx (16 in) | 4,459 cfm | 3,179 cfm | not published | not published | not published |
Source: RamFan UB20xx, EFi75xx and EFi120xx/EFi150xx data sheets.
What the figures say, in percentages we calculated from RamFan’s data: the UB20xx keeps about 81% of its free air through 15 feet and one turn, 68% with two turns and 63% through 25 feet with two turns. The EFi75xx keeps about 67% and 61%; the EFi150xx about 71% with one turn. On RamFan’s non-hazardous UB30, the one model with a straight-duct figure, 15 feet of straight duct keeps about 93% and each of the first two 90° turns costs roughly another 7 to 8 points. Two more traps: the UB20xx delivers 819 cfm free air at 50 Hz against 980 at 60 Hz, and RamFan’s manual says the EFi120xx is not designed to run efficiently on 60 Hz.
How do you size a blower for a confined space?
Start from the space volume and the ducted cfm. RamFan’s purge chart gives the minutes needed to exchange the air 7 1/2 times, by space volume and effective (ducted) blower capacity; it is taken from AT&T Standard Section 620-140-501, dated June 1976. In that chart a 10,000 cubic foot space takes 75 minutes at 1,000 cfm.
Worked example on the same basis (7.5 air changes): for a 10,000 cubic foot vessel, the UB20xx at 789 cfm through 15 feet and one turn needs about 95 minutes, the EFi75xx at 1,664 cfm about 45 minutes, and the EFi150xx at 3,179 cfm about 24 minutes. The chart’s own note matters as much as the numbers: the purge is effective only if the duct reaches the farthest corner from the entrance, or there is churning action.
Ventilation does not replace the confined-space program. OSHA 1910.146 requires continuous forced air ventilation under the alternate entry procedure, no entry until the ventilation has eliminated any hazardous atmosphere, air from a clean source, and periodic testing, and it notes that control of atmospheric hazards through forced air ventilation does not constitute elimination of the hazards.
Which duct, plug and cord keep the setup within its rating?
- Duct: RamFan’s manual requires duct used in a potentially explosive environment to be statically conductive, with a surface resistance of 10^6 ohms or less.
- Plug: RamFan builds units with EN 60309-1 plugs unless noted, says the US and Canadian market has no standardized plug configuration for “EX-PROOF” use, and asks buyers to request plug options at the time of order. If a unit ships with flying leads, the ATEX certificate makes the end user responsible for selecting a compliant plug per EN 60079-14.
- Cord: RamFan’s cord table marks a 100 ft cord on the 115 V EFi150xx as “DO NOT RECOMMEND”; the EFi150xx draws 80 A at start and 15 A running on 115 V, and 40 A / 8 A on 230 V.
- Ambient: the T6 rating applies from -4°F to +104°F; check that against the work window.
Why the 230 V version matters on a long cord: RamFan’s “do not recommend” applies to the 115 V EFi150xx on a 100 ft cord, and at 230 V the running current is 8 A instead of 15 A. When the power source is far from the manway, ask about the EG8200XX-230 and the cord gauge RamFan specifies for your length.
When should you choose an air-driven (pneumatic) blower instead of an electric explosion-proof blower for confined space entry?
Choose air drive when compressed air is already on site and you want no electrical equipment at the blower. Coppus writes “Pneumatic-drive ventilators are often desirable for hazardous locations”, and Allegro calls its air motor “a non-electrical device reducing the possibility of igniting flammable gases”. The trade-off is a compressor sized to the blower, and documents that cover the air motor, carry the maker’s own declaration or describe the unit, rather than a third-party certificate for the whole blower.
- RamFan AFi75xx and AFi50xx: the data sheets print a motor certification string, “II 2 GD c T4+1° C < Ta <+40° C”, next to an operating temperature of -22°F to +104°F; ask RamFan which range applies. Euramco’s 2021 declaration says the air blowers were “built to comply with The Atex Directive 2014/34/EU” and names no Ex marking or notified body. RamFan’s IECEx certificate UL 13.0062X (Zone 1 and 2) covers the electric UB20xx, EFi75xx, EFi120xx and EFi150xx.
- Air Systems SVB-A8: listed as “CE Registered”, while the electric SVB-E8EXP beside it is “CSA C/US certified for Classes I and II, Groups C, D, E, F, and G.”
- Coppus and Allegro: Coppus calls its RF reaction fans “ideal for hazardous locations”; Allegro’s web page gives the 9508 an “ATEX certified air motor”. Neither prints a certificate number.
None of these documents, read on 14 October 2026, shows a US Class/Division listing for an air-driven blower. Air drive removes the electric motor, not the need for a listing where your site requires one.
How much compressed air does a 12-inch pneumatic confined space blower need at 80 psi?
At 80 psig the 12-inch RamFan AFi75xx (AB7000) uses 40 scfm for 2,042 cfm, while the 12-inch Coppus RF-12 uses 61 scfm for 2,140 cfm. Airflow out divided by compressed air in is the induction ratio: 51:1 for the AFi75xx, 35:1 for the RF-12. RamFan matches the AFi75xx to a 6.4 hp single-stage piston compressor.
| Unit (type, duct) | Free air out | Compressed air in (ratio) | Noise; weight | Hazardous-area wording in the maker’s document |
|---|---|---|---|---|
| RamFan AFi75xx (air-motor fan, 12 in) | 2,042 cfm at 80 psig | 40 scfm (51:1) | 89 dB at 3 ft; 38 lb | Motor: “II 2 GD c T4+1° C < Ta <+40° C” |
| RamFan AFi50xx (air-motor fan, 16 in) | 3,200 cfm at 80 psig | 40 scfm (80:1) | 89 dB at 3 ft; 43 lb | Motor: “II 2 GD c T4+1° C < Ta <+40° C” |
| RamFan RV1500 (venturi cone, API 6 in) | 3,329 cfm at 80 psig | 124 cfm (27:1), matched by ratio | not published; 19 lb | “for safe use in adverse or explosive atmospheres when used with optional static grounding cord” |
| Coppus RF-12 (reaction fan, 12 in) | 2,140 cfm at 80 psig | 61 scfm (35:1) | 104 dBA at 5 ft; 39 lb | “ideal for hazardous locations” |
| Coppus Jectair 6-HP (venturi, 12 in) | 4,500 cfm at 80 psig | 126 cfm (35.7:1) | 92 dBA at 5 ft (Jectair 6); 21 lb | bonding cables “when operating in hazardous locations” |
| Air Systems SVB-A8 (centrifugal, 8 in) | 3,000 cfm at 100 psi | 5 to 85 cfm over 10 to 100 psi (ratio not published) | 82 dBA at 3 ft, 80 psi; 61 lb | “CE Registered”; “4 HP pneumatic (intrinsically safe)” |
| Allegro 9508 (centrifugal, 8 in) | 1,700 cfm, pressure not stated | not published | not published; 53 lb | “ATEX certified air motor” (web page) |
RamFan’s venturi sheet does not label which cone each air-use figure belongs to; the RV1500 values are matched to its printed 47:1 and 27:1 ratios.
Venturis use more air, and extra pressure buys little: RamFan’s RV1500 goes from 2,740 cfm on 59 cfm of compressed air at 40 psig to 3,329 cfm on 124 cfm at 80 psig. By our arithmetic that is 21% more airflow for 110% more compressed air.
How much airflow does an air-driven blower lose through duct?
Ask for a ducted figure, because RamFan publishes free air only for the AFi models. The Coppus RF-12 still moves 1,870 cfm through 50 feet of straight 12-inch duct, 87% of its free air by our calculation; the SVB-A8 drops from 3,000 to 1,725 cfm through 25 feet with one 90° bend (57.5%), and the Allegro 9508 from 1,700 to 1,350 cfm through 15 feet with one bend (79%).
How do you ventilate a tank with flammable vapors using an air-driven blower or exhauster?
Bond the blower and its duct, keep the air motor’s lubricated exhaust out of the airstream, secure the unit before admitting air, as Coppus instructs for its Jectair, and avoid pulling a vacuum on a closed vessel, which Coppus warns could collapse it. Where explosive or volatile vapors are suspected, Air Systems points to ANSI/API 2015 and 2016 procedures for grounding the blower, and says air quality should be tested before ventilating and continuously while the space is occupied.
- Bonding and duct: RamFan says conductive-housing units may need statically conductive duct, with the static clip on the adapter’s grounding post; Air Systems says to test conductive duct semi-annually and retire it above 300k ohms.
- Air line: RamFan wants a moisture trap and filter ahead of a lubricated motor, which exhausts outside the duct, so compressed air does not enter the airstream.
- Duct size: AFi75xx, two 12-inch adapters plus an optional 12-to-8-inch reducer (EC0301); RF-12, 12-inch duct; SVB-A8 and 9508, 8-inch flanges.
- Order code: order by the data-sheet part numbers, AB7000 for the 12-inch AFi75xx and AA7000 for the 16-inch AFi50xx, and check the part number on the order.
The RamFan AFi75xx (AB7000) is available from PE Energy Industrial Supply, 2700 Greens Rd H300, Houston, TX 77032 (281-310-0628, pesales@pe-energy.com), an authorized RamFan distributor that also lists the AFi50xx (AA7000) and the RV-series venturi cones. For a quote, add the compressed air available at the blower (scfm at psig) to the list below.
Where can you buy a hazardous-location blower in Houston, Texas, and what should the quote request include?
- Area classification: class, division or zone, gas group and temperature class, and whether the site requires an NRTL listing or accepts ATEX/IECEx equipment with an employer’s demonstration.
- Space volume, entry points and the purge time or air-change target your entry procedure uses.
- Duct diameter, length and number of bends, so the supplier quotes ducted cfm.
- Voltage, frequency and the plug or receptacle used on site, plus cord length.
- Ambient temperature range during the work.
Send the list above to pesales@pe-energy.com or call 281-310-0628, and we will tell you which RamFan model fits, or say so when the listing you need is one RamFan does not hold.
Where do these figures come from?
- RamFan certificates: ATEX DEMKO 09 ATEX 0926969X Rev. 7, IECEx UL 13.0062X issue 7, ATEX and UKEx declaration of conformity.
- RamFan data sheets: EFi120xx/EFi150xx, EFi75xx, UB20xx, UB30; EFi75xx/EFi120xx/EFi150xx manual; hazardous-location catalog; certification string page; purge times chart.
- Databases searched 10 October 2026: IECEx certificates, UL Product iQ, CSA Group certified product listing.
- OSHA: 29 CFR 1910.307, 1910.399, 1910.146.
- Air-driven units: RamFan AFi75xx and AFi50xx data sheets, AFi manual, pneumatic declaration of conformity and venturi cone sheet; Coppus 2024 catalog (Curtiss-Wright); Air Systems SVB Series manual and 2021 catalog pages 63 and 64; Allegro 9508 data sheet and product page.
Summary: choosing a hazardous-location confined-space blower
- Match the blower to the documented classification: Class I, Division 1 with an NRTL requirement needs a US-listed Division 1 blower; ATEX/IECEx Zone 1 equipment fits Class I, Zone 1 locations it is approved for, or a site where the employer demonstrates protection.
- The RamFan EFi150xx is certified II 2 G Ex db eb IIB T6 Gb (Zone 1 and 2) under ATEX, IECEx, UKEX and INMETRO; on 10 October 2026 we found no UL or CSA Class/Division listing for it.
- Size on ducted cfm: EFi150xx 3,179 cfm through 15 feet and one turn (4,459 free air); UB20xx 789 cfm (980 free air); EFi75xx 1,664 cfm (2,500 free air).
- Use statically conductive duct, settle the plug at order time, and keep long 115 V cord runs off the EFi150xx.
- Air-driven (pneumatic) blowers keep electrical equipment off the blower but need a matching compressor (RamFan AFi75xx: 2,042 cfm on 40 scfm at 80 psig); their documents show a motor marking, a maker’s declaration or a CE registration, not a US Class/Division listing, so ask for the certificate before ordering. PE Energy Industrial Supply in Houston, Texas, an authorized RamFan distributor, lists the AFi75xx (AB7000).
- Ventilation supports, but does not replace, atmospheric testing and the permit-required confined-space program under OSHA 1910.146.