A flameproof junction box can carry a PESO certified gland on every cable and still fail inspection. The cause is usually a smaller part. A reducer bought from another supplier to step an M25 entry down to M20. A spare entry closed with whatever plug was in the store. In an Ex d enclosure each of those parts sits in the flame path, so each one needs its own certification.
Exgrip now holds that certification across the full entry. One approval series, P675044, covers two PESO certified cable glands (E1FW and A2F) and five fitting products. Those are reducers and adapters, hexagonal head and dome stopping plugs, and 90° and Y adapters. Below are the certificate numbers, what each part does, and the entry rules that decide whether the finished assembly stays compliant. For background on how approval from the Petroleum and Explosives Safety Organisation works, start with our guide to PESO approval requirements for cable glands.
Why PESO Certification Has to Cover the Whole Cable Entry?
What Counts as Part of a Flameproof Entry?
A flameproof enclosure does not stop gas getting in. It contains an explosion inside and cools the escaping gases through long, tight joints so they cannot ignite the atmosphere outside. Every threaded entry is one of those joints.
IEC 60079-1, the standard IS 2148 is aligned with, deals with entries in clause 13. Its Annex C sets separate construction and test requirements for Ex blanking elements (stopping plugs) and Ex thread adapters (reducers and adapters). Once a reducer is screwed into an entry, it is part of the enclosure wall. So is a stopping plug. If either one is uncertified, the enclosure’s certificate no longer describes what is installed. The gas group and zone still have to be right as well. Our guide to Zone 1 and Zone 2 gland selection covers that side, and ATEX and IECEx marking explains the codes on each part.
Four Entry Mistakes Inspectors Find
- Two adapters stacked on one entry. IEC 60079-1 allows no more than one thread adapter per entry. An M40 to M32 reducer followed by an M32 to M20 reducer is not acceptable; one M40 to M20 reducer is.
- A stopping plug screwed into a reducer. A blanking element cannot be used together with a thread adapter. A spare M25 entry is closed with an M25 plug fitted directly into the enclosure.
- A plastic transit plug left in a spare entry. The caps fitted for shipping are not blanking elements. Before commissioning they must be replaced with certified metal stopping plugs.
- Too few threads engaged. The thread is the flame path, so engagement length matters. A plug or reducer backed off to make room for a locknut can end up below the five full threads usually required for metric entries.
Exgrip's PESO Certified Cable Glands and Fittings
Gujarat is home to some of India’s largest industrial corridors from the Jamnagar refinery belt to the chemical clusters of Vadodara and Ankleshwar, the solar parks of Kutch and Patan, and the marine infrastructure along the Saurashtra coast. Exgrip’s cable glands serve a broad range of industries operating across the state.
| Product | What it does | PESO | ATEX / IECEx | Groups | Metric / NPT sizes |
|---|---|---|---|---|---|
| A2F | Single compression cable gland | P675044/1 | ETL25ATEX0489X / IECEx ITS 25.0006X | I, IIC, IIIC | M16–M90 / 1/2″–3-1/2″ |
| E1FW | Double compression cable gland for armoured cable | P675044/2 | ETL25ATEX0489X / IECEx ITS 25.0006X | I, IIC, IIIC | M16–M90 / 1/2″–3-1/2″ |
| ADP adapter | Small male thread to larger female thread | P675044/3 | ETL25ATEX0489X / IECEx ITS 25.0006X | I, IIC, IIIC | M16–M90 / 1/2″–4″ |
| RED reducer | Large male thread to smaller female thread | P675044/8 | ETL25ATEX0489X / IECEx ITS 25.0006X | I, IIC, IIIC | M16–M90 / 1/2″–4″ |
| PLG stopping plug | Hexagonal head plug for unused entries | P675044/4 | ETL25ATEX0489X / IECEx ITS 25.0006X | I, IIC, IIIC | M16–M90 / up to 4″ |
| PLD stopping plug | Dome head plug, allen key drive | P675044/5 | ETL25ATEX0489X / IECEx ITS 25.0006X | I, IIC, IIIC | M16–M90 / up to 4″ |
| 90° ADP | Turns an entry through 90° | P675044/6 | ETL24ATEX0474U / IECEx ITS 24.0050U | IIC, IIIC | M20–M32 / 1/2″–1″ |
| YADP | Splits one entry into two | P675044/7 | ETL24ATEX0474U / IECEx ITS 24.0050U | IIC, IIIC | M20–M32 / 1/2″–1″ |
All eight are available in brass, nickel plated brass and stainless steel grades 304, 316L and 316.
PESO Certified Cable Glands: E1FW and A2F
E1FW Double Compression Cable Gland
The E1FW is the gland for armoured cable. Exgrip’s datasheet covers all types of steel and aluminium wire armoured cable. As a double compression cable gland, it seals on the inner sheath, clamps the armour wires, and seals again on the outer sheath. The armour stays terminated while water and dust stay out (IP66, IP67 and IP68). PESO certificate P675044/2 covers it for Group I mining, Group IIC gas and IIIC dust.
A2F Single Compression Cable Gland
The A2F seals with a single compression and is used on unarmoured cable. Its certification matches the E1FW: Ex db and Ex eb I Mb and IIC Gb, plus Ex ta IIIC Da, under PESO P675044/1. It is available as a brass cable gland, or in nickel plated brass or stainless steel for corrosive sites. For current stock, see the A2F sizes available from stock. To match either gland to a cable’s outer diameter, use the cable gland selection chart.
PESO Certified Reducers and Adapters
Reducer or Adapter: Which One You Need
Enclosure makers fix the entry sizes; the cable schedule rarely matches them. That gap is what thread conversion parts are for.
A reducer has a large male thread that screws into the enclosure and a smaller female thread that takes the gland. An M25 male to M20 female reducer lets an M20 gland sit in an M25 entry. An adapter works the other way round. Its male thread is the smaller one, so an M20 male to M25 female adapter lets an M25 gland fit an M20 entry. Buyers often search for that part as a cable gland enlarger. Both parts also come in NPT, for example a 3/4″ NPT male to 1/2″ NPT female reducer.
PESO certifies the two separately: reducers under P675044/8 and adapters under P675044/3. The ATEX and IECEx certificates are the same ones the glands carry.
Certified Size Range
Exgrip’s flameproof reducers and adapters cover M16 to M90 and 1/2″ to 4″ NPT, rated IP66 and IP67. Common jobs look like this:
| Entry on the enclosure | Gland you need to fit | Part |
|---|---|---|
| M25 | M20 | Reducer, M25 male × M20 female |
| M32 | M25 | Reducer, M32 male × M25 female |
| M40 | M20 | Reducer, M40 male × M20 female (one part, not two) |
| M20 | M25 | Adapter, M20 male × M25 female |
| 1/2″ NPT | 3/4″ NPT | Adapter, 1/2″ NPT male × 3/4″ NPT female |
The full matrix of metric and NPT combinations is on the reducers and adapters product page. The rest of the explosion proof fittings range sits in the same category.
90° and Y Adapters
The 90° adapter has one male and one female thread at a right angle. It is for entries where the cable cannot leave the wall in a straight line. The Y adapter takes one male entry and splits it into two female entries set 120° apart.
Both are made in M20 to M32 and 1/2″ to 1″ NPT, under PESO P675044/6 and P675044/7. Two differences from the rest of the range matter at specification stage. They are certified for Group IIC gas and IIIC dust but not Group I mining. And their ATEX and IECEx numbers end in “U”, which marks an Ex component certificate. The part is certified for use as part of certified equipment, so confirm the enclosure’s documentation allows it.
PESO Certified Stopping Plugs: Hexagon Head vs Dome Head
Junction boxes and local control stations often arrive with more entries than the job needs. Every unused one must be closed with a certified flameproof stopping plug before the equipment is energised. On site they get called blanking plugs, explosion proof stopping plugs or FLP stopping plugs. The requirement is the same whatever the name.
Exgrip makes two head styles:
| PLG | PLD | |
|---|---|---|
| Head | Hexagonal, sits proud of the enclosure | Dome with a recessed hex socket |
| Tool | Spanner | Allen key: M8 for M16, M10 for M20–M63, M14 for M75 and above |
| Metric sizes | M16–M90 | M16–M90 |
| NPT sizes | Up to 4″ | Up to 4″ |
| Ingress protection | IP66, IP67, IP68 | IP66, IP67, IP68 |
| PESO certificate | P675044/4 | P675044/5 |
The hexagonal head is quicker to fit and remove with tools already in a fitter’s bag. The dome head has a lower, rounded profile and can only be turned with the matching allen key. Both cover the common junction box entries (M20, M25, M32 and M40) as well as the larger entries on motor terminal boxes.
Where Certified Glands and Fittings Are Fitted?
Most hazardous area entries are on a short list of equipment: junction boxes, control stations, motor terminal boxes and lighting junction points. Each has entry sizes set by its manufacturer, and site cables are selected for current rating rather than to suit the box. A motor terminal box with an M40 entry, a cable that takes an M25 gland and one spare entry already needs a gland, a reducer and a stopping plug.
On refinery and petrochemical units in the Jamnagar belt, that combination repeats on every motor and field instrument. Our page on cable glands for oil and gas refineries covers those sites. Where the atmosphere is corrosive, as on many units in Dahej and Ankleshwar, the same parts come in stainless steel 316L; see cable glands for chemical plants.
Conclusion & Call-to-Action
Most entry problems are set up at the drawing stage, not on site. The datasheet lists the gland. The enclosure comes with whatever entries its maker chose. Reducers and plugs get bought later as consumables. That is the point where an uncertified part slips in.
The fix is to specify each entry as a set: the gland, any reducer or adapter, and a stopping plug for every spare entry, each with its own PESO number on the vendor document list. Send us the entry thread sizes, protection concept, cable details and number of spare entries for each enclosure, and Exgrip’s team will specify the full set of PESO certified cable glands and fittings, along with the PESO, ATEX and IECEx numbers for your documentation.
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FAQs
Do stopping plugs and reducers need PESO certification?
Yes, when they are fitted to a flameproof enclosure in an installation that falls under PESO. Each one forms part of the enclosure’s flame path, so an uncertified reducer or plug undermines the certification of the whole assembly. Exgrip’s PLG and PLD stopping plugs and RED reducers are certified under P675044/4, /5 and /8.
Can a reducer and a stopping plug be used on the same entry?
No. IEC 60079-1 does not allow a blanking element to be combined with a thread adapter. Close the spare entry with a stopping plug of the entry’s own size, fitted directly into the enclosure.
How many reducers or adapters can be fitted on one flameproof entry?
One. IEC 60079-1 limits each entry to a single thread adapter, so stepping M40 down to M20 needs one M40 to M20 reducer, not two parts in series. The 90° and Y adapters hold component certificates, so check the enclosure’s certificate before using them on an entry.
Can a plastic stopping plug be used on a flameproof enclosure?
No. Plastic plugs supplied with enclosures are transit caps and must be removed before commissioning. A flameproof entry needs a certified metal stopping plug in the correct thread, such as Exgrip’s brass or stainless steel PLG or PLD.
What sizes of PESO certified stopping plugs are available?
The PLG and PLD cover metric M16 to M90 and NPT sizes up to 4″. That includes the M20, M25, M32 and M40 entries found on most junction boxes and control stations. Both come in brass, nickel plated brass and three stainless steel grades.
Which Exgrip glands and fittings are certified for mining (Group I)?
The E1FW and A2F glands, the reducers and adapters, and both stopping plugs are certified Ex db I Mb and Ex eb I Mb. The 90° and Y adapters are certified for Group IIC gas and IIIC dust only, so they should not be specified for Group I mining equipment.