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Edwards · Other
Edwards Diffstak 250 — oil diffusion pump
Original title: Edwards Diffstak 250 Large Oil Diffusion Pump
📍 United Kingdom
🔴 Check carefully
Oil diffusion pump unsuitable as WAVE freeze-dryer vacuum source; requires backing pump.
Condition from photo
Exterior shows age and oil residue; corroded base, visible wear on bellows, label legible but faded.
Likely refurb / add-ons
- Backing pump (rotary vane or rotary piston) — €800–2000
- Oil change + exhaust filter service — €150
- Soft-starter or control unit — €300–500
Watch out for
- Oil diffusion pumps require a dedicated backing pump; cannot operate standalone.
- Visible corrosion and oil seepage suggest internal wear; internal condition unkn
- No backing pump included; total system cost will be significantly higher.
WAVE AI estimate from photo + specs only — not a substitute for our physical pre-purchase check.
Specifications
- Type
- other
- Pumping speed
- ~0 m³/h
- Water-vapour tolerance
- ~0 g/h
- Ultimate vacuum
- —
- Source
- eBay
- Listing #
- eBay #267688170112
- Last verified
- Jul 5, 2026
Price history— Edwards Other
Median €2.688 · 820 observations · €303–€33.328
Type plate (AI reading)
- Exact model
- Diffstak 250
- Model
- 250
- Fluid charge
- 500 ml
- Heater watts
- 225 W
- Heater volts
- 240 V
- Manufacturer
- Edwards High Vacuum (Part of BOC Ltd), Crawley, England
Auto-extracted from one of the listing photos. Verify on the real unit before purchase.
What to look for on this family
Generic Edwards vacuum pump — model family not auto-detected. Send us the listing URL for a free identification + suitability check.