Product Overview
What is Expanded Graphite Gland Packing?
Expanded (or flexible) graphite gland packing is a braided/seamed sealing material made from exfoliated natural graphite. The expansion process produces flexible graphite fibers that are braided into square or multi-plait packings, providing excellent thermal stability, low friction, chemical resistance (many hydrocarbons and solvents), and good sealing performance in high-temperature and high-pressure services.
Typical Constructions & Grades
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100% expanded graphite braid — pure graphite braid for maximum temperature and conductivity.
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Graphite with stainless steel wire core — for dimensional stability and higher pressure.
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Graphite-PTFE hybrid braid — improved chemical resistance in aggressive media.
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Graphite with aramid/nylon reinforcement — better mechanical strength for abrasive or high-pressure duties.
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Pre-formed valve rings / pumped kits — precision cut rings for valve stems and pump shafts.
Key Features & Buyer Benefits
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High temperature capability — continuous service up to ~400°C, short excursions up to ≈450–500°C in non-oxidizing atmospheres (grade dependent).
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Excellent chemical compatibility — resistant to hydrocarbons, steam, oils and many solvents (avoid strong oxidizers without testing).
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Low friction & shaft protection — natural graphite film reduces shaft/stem wear.
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Electrical conductivity — helps dissipate static where needed.
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Flexible & conformable — seals uneven shaft surfaces and recovers from compression.
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Available forms — spools (cut-to-length), pre-formed valve rings, seamless braided rings and OEM kits.
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Customizable — options for wire reinforcement, PTFE hybridization, aramid cores and packaging.
Applications
Applications-
Boiler and steam service (valves & pump glands)
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Hot oil and thermal fluid circulation pumps
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Petrochemical and refinery pumps & valves
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Heat exchangers, turbines and compressors (gland seals)
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Vacuum pumps (special low-ash grades)
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High temperature valves (gate, globe, check, ball)
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Marine and naval engineering (shaft seals)
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General industrial rotating and reciprocating equipment
Technical Specifications
Note: Exact performance depends on grade, reinforcement and installation. Request specific datasheet for the grade you intend to buy.
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Base material: Expanded natural graphite (flexible graphite)
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Construction: Square braid (3.0–12.0 mm cross sections), 8/12-strand or multi-ply braid; pre-formed rings available.
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Continuous service temperature: −200°C to +400°C (typical).
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Short excursion temperature: up to ≈450–500°C in non-oxidizing atmospheres (grade dependent).
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Max recommended pressure: up to 20 MPa (≈200 bar) depending on gland design, reinforcement and application.
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Max shaft speed: up to 12–15 m/s (application dependent).
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pH compatibility: Broad (approx. pH 0–14) for many grades, but avoid concentrated oxidizing acids at high temperature.
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Electrical conductivity: Conductive (typical surface resistivity low — suitable for static discharge applications).
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Typical spool lengths: 5 m, 10 m, 20 m (custom lengths available).
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Pre-formed valve ring sets: Supplied as 3-ring sets by stem diameter; custom ring counts on request.
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Certifications & testing: ISO 9001 manufacturing, batch certificates, MSDS, density and ash content reports available.
Common Sizes (industry standard & real-world)
Square cross-section sizes (metric / imperial):
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3.0 mm (≈1/8″)
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4.0 mm (≈5/32″)
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5.0 mm (≈3/16″)
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6.0 mm (≈1/4″)
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8.0 mm (≈5/16″)
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10.0 mm (≈3/8″)
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12.0 mm (≈1/2″)
Valve pre-formed ring set examples (typical):
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1/4″ stem → 3 rings × 3.0 mm
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1/2″ stem → 3 rings × 6.0 mm
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3/4″ stem → 3 rings × 8.0 mm
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1″ stem → 3 rings × 10.0 mm
Packaging examples:
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Coil / spool in sealed polyethylene + carton + pallet.
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Pre-formed valve kits: 3 rings per set in film and box.
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Reinforced variants in crates for export.
Advantages — Why Buyers Choose Expanded Graphite Gland Packing
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Superior high-temperature performance — reliable in steam and high-heat systems.
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Excellent sealing with low leakage — graphite conforms and recovers under gland pressure.
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Strong chemical tolerance — suitable for many aggressive media (except concentrated oxidizers at temperature).
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Low friction & shaft protection — reduces wear and maintenance on polished shafts.
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Electrical conductivity — helps dissipate static and reduce charge build-up in hydrocarbon services.
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Flexible customization — wire cores, hybrid impregnation (PTFE) or fiber reinforcement to suit duty.
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Cost effective in critical services — longer runtime, less downtime and lower lifecycle cost versus some polymer packings.
Material Comparison Table (purchase-focused)
| Property / Material | Expanded Graphite Gland Packing | PTFE Packing | Graphite-PTFE Hybrid | Aramid (Kevlar®) Packing |
|---|---|---|---|---|
| Temp capability | High (to ~400°C continuous) | Moderate (~260°C) | High (~260–300°C) | Moderate (~250°C) |
| Chemical resistance | Wide (hydrocarbons, steam) | Excellent (most chemicals) | Excellent (balanced) | Good (hydrocarbons) |
| Shaft wear | Low | Very low | Low | Low–medium |
| Abrasion resistance | Medium | Low | Medium | High |
| Conductivity | Conductive | Non-conductive | Low–moderate | Non-conductive |
| Best for | Steam, hot oil, high-temp valves | Highly corrosive chemistries | Mixed high-temp + chemical services | Abrasion/high mechanical load |
| Typical cost | Mid | Mid-high | Mid | Mid |
Recommendation: Choose expanded graphite gland packing where temperature and sealing under steam/hot oil is primary. For extreme chemical corrosion choose PTFE; for abrasive solids choose aramid-reinforced variants.
Installation & Best Practices
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Shaft/stem finish: recommended Ra ≤ 0.8 µm; smooth, undamaged surface.
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Gland setup: install full rings, stagger joints if using cut rings, tighten in small increments while running until leaks are controlled.
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Run-in: some initial bleed is normal; re-adjust gland after run-in.
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Avoid mixing: do not mix different materials or old/new rings.
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Cooling & flushing: use lantern rings and flush for slurry or high temp pressurized services.
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Inspection: inspect shaft and gland for scoring — replace damaged components prior to packing installation.
Ordering, Packaging & Shipping Options
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MOQ (typical): 20–100 kg per SKU for standard grades. Smaller sample orders available.
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Lead time (typical): Stock grades: 3–7 business days. Custom grades / wire-reinforced / pre-formed kits: 7–15 business days.
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Shipping terms: EXW / FOB / CIF / DDP (negotiable). Samples by courier (DHL / UPS / FedEx); bulk by sea/air per buyer preference.
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Export packaging: sealed spools, labeled cartons, palletized; export documentation (COO, commercial invoice, packing list) provided.
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Payment: T/T, L/C at sight, PayPal for small orders; terms negotiable for repeat or large buyers.
FAQ
Q: What is the minimum order quantity (MOQ)?
A: Typical MOQ is 20–100 kg per SKU. We accept smaller sample or trial orders — contact sales with size/grade for exact MOQ.
Q: How long is the lead time?
A: Stock grades ship in 3–7 business days. Custom grades, wire-reinforced or pre-formed kits typically 7–15 business days depending on order size.
Q: What shipping terms and carriers do you use?
A: We ship EXW / FOB / CIF / DDP. Samples by courier (DHL/UPS/FedEx); bulk orders via sea (FCL/LCL) or air. Full export docs provided (COO, commercial invoice, packing list).
Q: Can you supply pre-formed valve rings and pump packing kits?
A: Yes — pre-formed sets, cut-to-length spools and complete pump kits with lantern rings and installation instructions are available.
Q: Can the packing be reinforced or hybridized?
A: Yes — options include stainless wire core for pressure, aramid/nylon reinforcement for abrasion, or PTFE hybridization for enhanced chemical resistance.
Q: Is expanded graphite packing suitable for steam?
A: Yes — many grades are optimized for steam service. Select the correct grade and gland setup; we recommend engineering review for high-pressure/high-temperature steam duties.
Q: What about warranty and quality assurance?
A: We provide warranty against manufacturing defects. Each batch has QA checks (dimensional, ash content, density) and we supply batch certificates on request.
