SRM16-12 Gas-Insulated Ring Main Unit
The SRM16-12 gas-insulated ring main unit is manufactured by LYE Technology for indoor 12 kV distribution automation, with the main switch available as a permanent-magnet or spring-mechanism vacuum circuit breaker. Its sealed compartment is 3 mm stainless steel, robot welded, rated IP67 with an independent pressure-relief channel per compartment.
- Type: Indoor AC HV gas-insulated metal-enclosed switchgear
- Main switch: Permanent-magnet or spring-mechanism vacuum circuit breaker
- Insulation: Air insulation combined with sealed gas compartments
- Gas compartment: 3 mm stainless steel, CNC machined, robot welded
- Standards: GB/T 11022-2011, GB/T 3906-2006
Gas-Insulated Ring Main Unit: Key Features & Typical Use
Sealed Compartments, Robot-Welded
The gas compartment is fabricated from 3 mm stainless steel plate, machined on CNC equipment and welded by welding robots. Robot welding keeps deformation low and repeatability high, which is what determines whether a sealed compartment holds its gas over a twenty-year life. The remaining compartments use quality cold-rolled steel formed by CNC bending.Air Insulation Combined with Sealed Gas
The design mixes air insulation with gas-insulated compartments rather than relying on one medium throughout. That keeps the unit compact while retaining the creepage behaviour engineers already understand, and it makes the equipment expandable: additional functional units are added as modules instead of replacing the whole switchboard.Component Choice Without a Rebuild
The main switch can be supplied with either a permanent-magnet mechanism or a spring mechanism vacuum circuit breaker. A utility that standardises on one mechanism and a developer who prefers the other can both be served from the same enclosure platform, and the operator interface, interlocks and cable terminations remain familiar.Independent Relief for Every Compartment
Each sealed compartment has its own pressure-relief channel, so gas released during an internal fault is directed away from the operating face and from adjacent compartments. The gas compartments are rated IP67 and the low-voltage cabinet IP4X, and the equipment is designed to the GB/T 11022-2011 and GB/T 3906-2006 standards.Gas-Insulated Ring Main Unit Specifications & Technical Data
| Parameter | Details |
|---|---|
| Product | SRM16-12 gas-insulated ring main unit |
| Equipment type | Indoor AC high-voltage gas-insulated metal-enclosed switchgear |
| Main switch | Permanent-magnet mechanism or spring mechanism vacuum circuit breaker |
| Insulation arrangement | Air insulation combined with sealed gas compartments |
| Gas compartment material | 3 mm stainless steel plate, CNC machined and robot welded |
| Other compartment material | Quality cold-rolled steel plate, CNC bent and welded |
| Functional units | Independent modules with simple assembly |
| Pressure relief | Independent relief channel for each sealed compartment |
| Gas compartment protection | IP67 |
| Low-voltage cabinet protection | IP4X |
| Applicable standards | GB/T 11022-2011, GB/T 3906-2006 |
| Typical applications | Small secondary substations, switching stations, box substations, residential communities |
| Special applications | Airports, subways and railways with high supply reliability requirements |
SRM16-12 — Gas-Insulated Switchgear for Compact, Expandable Distribution
Where floor space is scarce and supply reliability is not negotiable, an air-insulated switchboard becomes difficult to fit. The SRM16-12 seals its main switching functions inside a gas compartment and keeps the rest of the unit air insulated, so the switchgear stays compact without giving up familiar wiring and creepage behaviour.Buyers searching for this equipment use several names for the same product: gas insulated RMU, SF6 ring main unit, ring main unit (RMU), or inflatable cabinet. It is also compared with air-insulated switchgear (AIS) and with solid-insulated designs. The decisive questions for a switchroom are the short-circuit rating, the degree of protection and how the enclosure is welded, because that is what determines whether the gas stays in over a twenty-year life.The gas compartment is built from 3 mm stainless steel, machined on CNC equipment and welded by robot, which keeps distortion low and gas tightness repeatable. Every sealed compartment has its own pressure-relief channel, and the functional units are independent modules, so a board can be extended later by adding units rather than rebuilding the room.The unit is designed for distribution automation in small secondary substations, switching stations, box substations, residential communities and large commercial buildings, and is particularly suited to airports, subways and railways where an outage is expensive. LYE manufactures the enclosures in-house and supplies project documentation to the applicable GB standards.Factory-Direct Gas-Insulated Ring Main Unit Manufacturer & OEM / ODM
We Manufacture, You Brand
LYE Technology (Zhejiang) Co., Ltd. is a national high-tech enterprise and manufacturer in Wenzhou, China: sheet-metal fabrication, welding, powder coating, busbar machining and final assembly run on our own factory lines, and every unit is function-tested before it leaves the works. A SRM16-12 Gas-Insulated Ring Main Unit that reaches your site carries the routine test behind it, not just the rating on the nameplate.We are one of the Top 10 Brands of China's small power distribution boxes and a drafter of national standards in this category, and we hold ISO9001, ISO14001, ISO45001, CCC, CE and TUV certification. Because we are the manufacturer rather than a trading company, our sales engineers quote from your drawing in factory-direct terms, and OEM or ODM work is produced on the same lines as our standard products.For the SRM16-12 we weld the sealed compartments on robotic lines and test gas tightness before assembly, so the enclosure that arrives on site already carries its routine test record.- OEM branding — custom colours, laser marking and your own project or retail packaging, applied at the factory.
- ODM options — ratings, configurations and internal layouts built around your drawings or single-line diagram.
- Certification — ISO9001, ISO14001, ISO45001, CCC, CE and TUV, with test documents supplied per project.
- MOQ — flexible quantities for a project or a trial order, with mixed types welcome in one shipment.
SRM16-12 sealed gas compartment with robot-welded stainless steel shell
Modular functional units assembled side by side
Gas-Insulated Ring Main Unit Buying Guide from the Manufacturer
Gas-insulated switchgear is specified by scheme rather than by unit, so the conversation starts with the incoming arrangement and the number of outgoing ways. These are the points we confirm.
- Confirm the system voltage, frequency and the required short-circuit rating for the installation.
- Decide the main switch mechanism: permanent-magnet or spring-mechanism vacuum circuit breaker.
- Set the incoming, outgoing and bus-tie arrangement and the number of functional units required.
- Confirm the degree of protection needed and the environmental conditions at the site.
- Send the single-line diagram, room dimensions and cable termination details.
- Approve drawings, then production with gas-tightness and functional testing before dispatch.
Manufacturer & Sales Support for Wholesale Buyers
OEM / ODM
Learn more →Factory colours · Logo marking · Custom layout
Wholesale
Learn more →Factory pricing · Flexible MOQ · Global shipping
Distributor Support
Learn more →Account manager · Drawing support · Priority lead times
Planning a Gas-Insulated Ring Main Unit Solution?
OEM/ODM, wholesale pricing and distributor support straight from the manufacturer — one enquiry gets you a factory-direct quotation for the SRM16-12 Gas-Insulated Ring Main Unit, sized to your single-line diagram, room dimensions and the switch mechanism standard your utility follows, with type-test documentation under GB/T 11022-2011 and GB/T 3906-2006. Our sales team replies with a specification and an indicative price, so send your drawings and quantity.Contact Our Sales TeamGas-Insulated Ring Main Unit — Frequently Asked Questions
What is a gas insulated RMU?
A gas insulated RMU is a ring main unit in which the main switching functions are enclosed in sealed compartments insulated with gas instead of air. The arrangement makes the unit compact and keeps dust, humidity and contamination away from the live parts. The SRM16-12 is an indoor 12 kV gas-insulated metal-enclosed switchgear unit with air insulation combined with sealed gas compartments.What is a ring main unit used for?
A ring main unit is used to connect and switch sections of a distribution ring, so a fault on one cable section can be isolated without shutting down the whole network. Typical applications are small secondary substations, switching stations, box substations, residential communities, industrial and commercial buildings, and locations such as airports, subways and railways where an outage is expensive.What is an AIS and how does it differ from a GIS?
AIS means air-insulated switchgear, where the live parts are insulated by air at atmospheric pressure; GIS means gas-insulated switchgear, where they sit inside a sealed gas-filled enclosure. AIS is simpler to inspect but needs more floor space and is more affected by dust and humidity. GIS is far more compact and effectively maintenance-free, which is why it is chosen for small substations, tunnels and coastal or polluted sites.Who manufactures gas insulated ring main units?
The category is dominated by international switchgear brands and by Chinese manufacturers who build to the same GB and IEC standards. When comparing manufacturers, ask how the sealed compartment is formed and welded, whether gas tightness is tested on the finished enclosure, and which standard the type test was carried out to. LYE manufactures the SRM16-12 enclosure in Wenzhou with robot welding and holds ISO9001, ISO14001, ISO45001, CCC, CE and TUV certification.How much does a gas insulated ring main unit cost?
Indicative factory-direct pricing is roughly US$3,000 to US$20,000 per cubicle or unit, depending on the number of functional units, the main switch mechanism, the protection rating and the quantity. Because a ring main unit is specified as a scheme rather than a single item, the most useful starting point for a quotation is the single-line diagram and the room dimensions, which let the arrangement and therefore the price be compared properly.
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Use a distribution box for final circuits and compact branch protection; use a cabinet when the project needs larger incoming capacity, more feeder groups, metering, busbars or greater internal separation. The final choice should be checked against the single-line diagram, device list, available installation space and local project rules.
Provide the device schedule, circuit quantity, component dimensions, cable-entry direction, mounting method and required spare capacity. LYE also reviews door clearance, bending radius, heat-producing devices and the usable depth behind the mounting plate before confirming an enclosure size.
Start with the actual exposure to dust, rain, cleaning water and accidental contact rather than choosing the highest number by default. Cable entries, ventilation, door seals and installation workmanship affect the finished assembly, so the target rating and verification basis must be confirmed for the specific product and project.
Coated or galvanized steel is commonly considered for general indoor service, stainless steel for humid or corrosive locations, and engineering plastic for lightweight non-metallic applications. Material grade, thickness, UV exposure, chemical contact and earthing requirements must be confirmed against the installation environment.
Share the component heat load, ambient temperature, solar exposure, duty cycle and allowable internal temperature. LYE can then review enclosure volume, spacing, ventilation or fan provisions, sun shields, heaters or drainage details; the final thermal design remains tied to the installed equipment and site conditions.
Yes. A dimensioned drawing is preferred, but a physical sample and clear reference photographs can also start the review. Material, thickness, openings, hardware, finish, labels, inspection points and packing are recorded before sampling or repeat production.
PDF and common 2D CAD drawings are suitable for most enclosure enquiries, while 3D files can help with complex assemblies. Include a revision number, units, tolerances and component references; file compatibility and any missing production information will be confirmed during review.
A sample or first article can be arranged for a new or customized product. The approval plan should identify dimensions, openings, fit, appearance, hardware, labels and packaging, together with the sample cost and timing agreed for the actual order.
Available documents may include approved drawings, packing lists, dimensional or appearance inspection records, product data and certificates applicable to the confirmed model. Destination-specific declarations or third-party testing must be requested before order placement so availability and scope can be verified.
Lead time is confirmed after the product scope, quantity, sample requirement and finish are known. Packing is reviewed against product weight, surface protection, destination and shipping method; if an issue is found after delivery, send the order reference, label, photographs and quantity affected so it can be traced and reviewed.
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