Power Generation & Distribution Gaskets
From superheated steam at 540 °C to transformer oil containment — gaskets that keep the grid running.
Australia's thermal generation fleet is ageing fast. Eraring closes in 2027. Yallourn follows in 2028. The Australian Energy Market Operator (AEMO) Integrated System Plan locks in further coal retirements through 2035. Asset owners are running plant harder while deferring capital, so gasket reliability through life-extension matters more than ever. We stock everything you need for the next shutdown: spiral wound gaskets for main steam piping, Thermiculite for gas turbine exhaust, NBR-cork for transformers, and EPDM for cooling water. Kitted, delivered, and backed by engineers who speak your language.
Applicable Standards and Codes
Power station and network equipment sits under overlapping ASME, Australian, and IEC standards. We stock gaskets dimensioned to both ASME and AS 2129 flange standards and can advise on the right specification for each joint. The table below summarises the 18 standards most relevant to gasket selection in Australian generation and distribution plant.
Conventional Practice vs. Engineered Sealing
Materials and Operating Conditions
Power generation covers a wider temperature and pressure range than almost any other industry. Material selection here is safety-critical. Specify graphite where Thermiculite is needed and you risk gasket burnout and a forced outage.
Spiral Wound Gaskets: Filler and Winding Combinations
The distinction between steam service (graphite is fine) and oxidising service (Thermiculite mandatory) is safety-critical.
Kammprofile Gaskets
Reusable core with replaceable facing. Reduces long-term cost on heat exchangers and large-diameter joints.
Flexible Graphite Sheet
Temperature limits depend on atmosphere; graphite works far higher in steam than in air.
Available on tanged 316L SS insert or as plain sheet. Purity: 99%+ carbon for superheated steam; industrial grade with inhibitor for general service.
Creep & steam-cut resistance: Graphite creeps under sustained bolt load — retorque after the first thermal cycle is standard practice. For high-velocity steam (attemperators, bypass valves), specify 99%+ purity graphite with a metallic inner ring to resist steam-cut erosion across the gasket face.
Thermiculite (Vermiculite-Based)
Zero oxidation at any temperature within rating. Ultra-low halide content, so no SCC risk to stainless flanges.
NBR-Cork (Transformer Service)
- Shore Hardness:
- Shore A 70
- Temperature:
- −30 to +125 °C
- Oil Compatibility:
- All common transformer mineral oils (naphthenic and paraffinic)
- Sealing Stress:
- 3–20 MPa
Applications: Tank cover-to-body, conservator, radiator headers, bushing turrets, cable boxes, on-load tap changer (OLTC) compartments.
EPDM is NOT suitable for transformer oil service.
Compliant: asbestos-free, mercury-free, ceramic-fibre-free per IEC 60076-1.
EPDM
- Temperature:
- −40 to +120 °C
- Strengths:
- Water, UV, ozone resistance for outdoor Australian conditions
Applications: Cooling water systems (DN 600–1800 CW mains), GIS SF₆ seals (30+ year service life), electrical enclosures (IP67/IP68), underground cable pits.
NOT suitable for transformer oil, hydrocarbons, or solvents.
Compression Packing
- • Graphite packing for valve stems in steam service (HP, IP bypass valves, main stop valves)
- • PTFE packing for chemical dosing system valves (hydrazine, ammonia, caustic)
- • Aramid/PTFE hybrid packing for pump applications (boiler feed pump (BFP) suction/discharge isolation valves)
Packing is often overlooked in gasket kitting; include it in shutdown packages.
Spray Shields
- • Required on hazardous service flanges: fuel gas, hydrogen seal oil, lube oil, chemical dosing
- • Contain flange leaks and protect personnel from high-pressure spray
- • Stainless steel or PTFE construction depending on media
Site safety management systems specify these.
Key Applications by System
Boiler and Steam Cycle
- Main steam piping flanges: SWG 316L/graphite, Class 600–2500
- Hot reheat piping: SWG 316L/graphite (99%+ carbon), Class 300–600
- Boiler manhole and handhole gaskets (50+ openings per boiler)
- Feedwater heater channel gaskets: SWG graphite, Class 600–900
- Deaerator manholes and BFP flanges, 105–280 °C
- Attemperator / desuperheater connections with Inconel inner ring (thermal shock)
- Load-following and cycling units: graphite gaskets with creep-resistant inner rings to handle daily thermal transients
Gas Turbine and HRSG
- GT exhaust flanges: Thermiculite SWG or Kammprofile, 500–700 °C
- HRSG duct joints and casing gaskets handling large-area differential expansion
- Stack damper and diverter flanges: Thermiculite sheet, near-atmospheric
Graphite must not be used in oxidising GT exhaust service.
Condenser and Cooling Water
- Condenser waterbox cover gaskets: NPS 36–60+ EPDM or Kammprofile
- Circulating water piping: full-face EPDM, DN 600–1800
- CW heat exchangers using SWG with PTFE filler (lube oil coolers, H₂ coolers)
Hydrogen-Cooled Generator Auxiliaries
- Seal-oil supply & return flanges: SWG 316L / graphite, Class 300, 60–80 °C
- Generator endshield gaskets: segmental shapes, low-relaxation graphite
- Lube-oil interface seals using NBR or fluorocarbon where H₂ permeation is a concern
- H₂ purity 95%+ at 3–6 bar typical (Bayswater, Eraring, Loy Yang A, Stanwell, Tarong)
Generator-seal failures are a leading cause of forced outages — replacement programmes are time-critical.
Electrical and Transformer
- Power transformer tank gaskets: NBR-cork, Shore A 70, 30–50 year life
- Bushing gaskets (porcelain-to-steel) in NBR or silicone
- OLTC compartment gaskets that withstand degraded oil and carbon
- GIS SF₆ containment seals: EPDM O-rings, max 0.1%/yr leak rate (IEC 62271-203)
- Distribution transformer gaskets for volume replacement programmes
Ancillary Systems
- Fuel gas piping: SWG graphite, Class 150–600, fire-safe per API 607
- Chemical dosing using PTFE envelope or ePTFE gaskets
- Coal mill / pulveriser gaskets: graphite sheet with metal reinforcement
- Flue gas desulphurisation (FGD) / wet scrubber recycle slurry: PTFE-faced or fluoroelastomer (FKM) gaskets, 50–70 °C acidic service
- FGD limestone slurry headers using peroxide-cured EPDM full-face gaskets
- ESP / ID-FD fan duct expansion joints: neoprene-coated fabric or graphite, atmospheric service
Power Generation Sealing in Context
540 °C
Subcritical Main Steam
Standard for most Australian coal fleet. Supercritical plants reach 593 °C
108 Outages
NEM Coal Fleet, 2025–26 Summer
90 of 108 were unplanned. Gasket demand follows maintenance intensity
∼700,000
Distribution Transformers (est.)
Across Australia. NBR-cork gaskets with 25–40 year service life
0.1%/yr
Max SF₆ Leak Rate (IEC 62271-203)
GIS seals must hold for 30+ years. SF₆ has 23,500× CO₂ GWP (IPCC AR6, 100-year)
Products for Power Generation
Engineering Guides for Power Generation
Reference guides for pressure–temperature ratings, spiral wound gasket selection, and standard dimensions across ASME and Australian flange systems.
Browse All ResourcesExplore Further
Need Gaskets for Power Generation?
From outage kitting and main steam SWGs to transformer NBR-cork and GIS seals, we cover the sealing products a power station or network operator relies on day-to-day. Less common items come in through our supply network. Talk to our team about your next shutdown or ongoing supply requirements.
- Outage gasket kitting: pre-staged, site-ready
- Emergency and forced-outage supply on short lead times
- Large-diameter and custom-manufactured gaskets available
- Both ASME and AS 2129 flange dimensions in stock
- Bolt pairing guidance per ASME PCC-1
Disclaimer
This page is provided for general engineering reference only and does not constitute professional advice, specification, or guarantee of performance. Actual results depend on specific application conditions. Universal Gaskets Pty Ltd accepts no responsibility or liability for decisions made based on this information. For full terms, see our Terms & Conditions.
Temperature ranges, chemical resistance ratings, and mechanical properties cited on this page are typical values for standard grades. Actual performance varies with compound formulation, filler package, and service conditions — contact us to confirm suitability for your specific application.