Transformer service · Secondary containment
Specify a replaceable liquid barrier around transformer equipment by the exact insulating fluid, contact conditions and containment layout. DERFLEX supplies coated fabric roll materials for OEM fabrication; transformer service requires a fluid-specific construction review before material approval. Define mineral oil, natural ester, synthetic ester or another actual medium, then qualify the face coating, welded seams, corners and drain interfaces together.
Transformer oil containment liner fabric is a coated textile fabricated into the liquid-retaining layer of a secondary containment area beneath or around oil-filled equipment. A transformer bund liner material must be assessed for the actual insulating fluid and finished joint details. The surrounding structure, equipment supports and drainage arrangement determine how that layer works in service.
Selection starts with identity
“Transformer oil” is not a complete chemical specification. Record the manufacturer, trade name, fluid family and current SDS, then establish the liquid the liner could actually encounter. Include service history if the equipment has been retrofilled or topped up.
On smaller screens, scroll the tables horizontally to compare all fields.
| Actual medium | Identify before selection | Qualification focus |
|---|---|---|
| Mineral insulating oil | Exact product, relevant additives and whether the anticipated spill is new or in-service oil. | Evaluate the proposed mineral oil containment liner with that fluid at the agreed contact temperature and recovery time. Diesel data does not establish this result. |
| Natural ester fluid | Commercial fluid name, formulation documentation and any residual fluid from a previous fill. | Request direct evidence for the natural ester and all wetted components. A biodegradable-fluid claim does not establish liner or drain-media suitability. |
| Synthetic ester fluid | Specific product identity and supplier technical information. | Assess this fluid separately. Do not transfer mineral-oil or natural-ester results to an ester transformer fluid liner without supporting evidence. |
| Other or uncertain liquid | Identify silicone-based fluid, mixed residues, cleaning agents or an unknown service fluid through the responsible equipment team. | Resolve the identity before approving material. Include relevant mixtures or exposure sequences in the agreed assessment. |
For material development options, review DERFLEX oil-resistant TPU coated fabric. Its broader oil-contact positioning does not by itself approve a transformer application.
Duration changes the brief
A removable service liner and a liner in a fixed bund have different exposure, access and replacement requirements. Define the duty before selecting coating, reinforcement, roll width or a seam arrangement.
Describe the work area around drain points, hoses and service equipment, the expected deployment period and how collected liquid will be recovered.
Describe the supported floor, upstands, equipment plinths, external weather exposure and access available for inspection or replacement.
The project design must provide the equipment support and protect the flexible layer from point loads, abrasion and movement. Do not assume fabric can carry transformer feet, jacking loads or maintenance traffic. Record plinths, rails, cable routes, anchoring and any protective underlay in the layout.
Working containment capacity belongs to the complete geometry and operating plan. The designer must account for displaced volume, required reserve, precipitation and drain operating conditions. A fabric weight or a nominal wall height cannot establish the working capacity.
Use the spill containment berm fabric guide for general basin construction questions, then add the transformer-specific fluid and service requirements.
Draw the interfaces
The purchase drawing should show where the liner changes direction, meets a support or terminates at an interface. Include enough room to fabricate, inspect and replace those details.
The welded and sewn seam strength comparison explains joining mechanisms. A liquid-retaining liner additionally needs continuity-of-seal and post-exposure evaluation at its actual joint details.
A penetration is part of the barrier
An outdoor containment floor collects rain as well as potential leakage. Specify where water collects, how it is checked and the controlled route for removal. Keep the drain arrangement in the same approval scope as the liner.
Identify whether the site uses controlled pump-out, a managed valve arrangement or a separately qualified treatment device. Agree the operating condition, responsible person and response to suspected contamination with the system designer.
If a drain or filter relies on an oil-selective mechanism, obtain evidence for the actual insulating fluid. Mineral oil, natural ester and synthetic ester must not be assumed to produce the same response in a drain medium.
Include liner-to-boot weld, flange geometry, gasket, connector, hose or rigid pipe support and inspection clearance. Avoid transferring pipe loads into the fabric or leaving the underside of the connection inaccessible.
Provide a way to inspect and clean the collection point, service the drain components and verify the interface after intervention. Include sediment, outdoor debris and the actual cleaning products in the operating brief.
Approve a construction, not a material name
Use a written qualification plan linking the actual liquid to the proposed material and fabricated details. The following is a buyer’s review framework; it is not a DERFLEX transformer-fluid test report or a published approval for any grade.
| Specification block | State in the RFQ | Keep with the approval |
|---|---|---|
| Material and format | Candidate coating, base textile, wetted side, target mass (g/m²), thickness (mm), usable width and roll quantity. | Grade reference, tolerances, face identification and approved swatch. |
| Exposure | Fluid product/SDS, new or service liquid, liquid temperature (°C), contact duration and cleaning sequence. | Exposure protocol, laboratory sample IDs and results for the exact construction. |
| Mechanical and fabrication | Supported layout, contact hazards, strength requirements in both directions and the intended joining equipment. | Methods, specimen direction, acceptance limits and assembly trial records. |
| Interfaces and operation | Floor and upstand drawing, corners, plinths, drains, weather exposure and replacement route. | Drawing revision, complete component list and site acceptance responsibilities. |
No standard GSM, thickness, contact-time rating, minimum order quantity or service life is claimed here. Quote these only after the construction and commercial scope are defined.
Use the coated-fabric testing checklist to organize physical-property questions and the chemical-contact material review to frame the exposure brief. These related guides do not replace fluid-specific liner evidence.
Before you order
This page concerns coated fabric roll material for a liner fabricator or containment integrator. Finished liners, engineered supports, drain devices, installation and site compliance are separate scopes to agree. No complete system supply is implied.
Provide internal dimensions, levels, upstands, corner geometry, support positions and every penetration. Show weld access, reinforcement and replacement clearances. Do not treat a floor footprint as a finished cutting pattern.
Inspect high-contact zones, seams, folds, terminations and drains after installation, exposure and maintenance. Set the interval from actual service conditions. Define conditions for isolation, repair evaluation and retirement; widespread coating change or unresolved leakage needs review before reuse.
The liner is not a transformer rain cover, a fuel-storage vessel, an electrical insulating product or a fire-protection system. Any required fire performance, earthing provisions or equipment clearances need their own project assessment and evidence.
For general handling and visual inspection practices, see the coated tarp maintenance checklist. Fluid-exposed liner repair and retirement still require the approved application procedure.
Quotation variables include coating construction, usable roll width and cutting yield, trial sample scope, quantity, packing and delivery destination. Confirm sample availability, MOQ, lead time and documentation for the actual request.
Buyer questions
Only when evidence supports the exact liner construction for each intended fluid and exposure. Similar appearance or the shared term “insulating oil” does not establish interchangeability. Review wetted coatings, joints, gaskets, boots and drain components as part of each approval.
No. It may inform an initial material discussion, but it does not establish compatibility with a named insulating liquid. Request results for that fluid and the intended contact conditions, including the proposed welded and penetrated construction.
Start with the fluid and duty, then assess candidate constructions with the same exposure and assembly criteria. Polymer name and fabric mass alone do not establish resistance, barrier performance or service life. Approve a grade with defined coating, reinforcement, dimensions and tolerances.
A standard coated barrier should not be assumed to separate rainwater from insulating fluid. Define a controlled removal route or a separately qualified drain system. Any selective drain mechanism needs evidence for the actual fluid, along with the liner-to-drain interface.
That depends on support geometry, attachment, access and the liner’s removal path. Show those conditions on the layout and have the equipment and containment teams review the service procedure. Fabric flexibility alone does not make an installed liner replaceable.
Provide the insulating fluid product name and SDS, equipment-bottom and bund layout, expected temperature and contact duration, drain and corner details, fabrication method, quantity and destination. Include any existing fluid-contact report so the proposed sample can be compared on the same basis.
Prepare the next material review
Provide the insulating fluid specification and containment layout.
Use the existing DERFLEX inquiry page to describe your application and request a material review. Identify the SDS and drawing revisions available for follow-up, so the proposed roll material, sample scope and qualification work can be discussed together.
Copy the checklist, complete it, and paste it into your inquiry.