Why we disclose this
Figures circulate in this industry that nobody documents. "30 years' service life", "90 per cent less environmental impact" – all of it is written somewhere, and some of it does not stand up to a single question.
That is why we take the opposite route: every figure on this website has an origin, and we name it together with its classification. Figures without an origin we do not quote.
Standards
| Standard | Subject | Access |
|---|---|---|
| DIN 6647-1 | Beverage containers, pressure class up to 3 bar | chargeable via DIN Media |
| DIN 6647-2 | Beverage containers, pressure class up to 7 bar | chargeable |
| DIN 3542 | Spears | chargeable |
| DIN 32677 | Couplers | chargeable |
| DIN 6650-x | Beverage dispensing systems | chargeable |
Association and manufacturer documents
Freely accessible, technically substantial – and not neutral in their interests. We mark that where it counts.
| Source | What we use from it | Classification |
|---|---|---|
| Brewers Association Performance Guidelines for Refillable Kegs, Rev. 1, 2017 | Service life 10 to 30 years or 60 to 180 cycles · operating pressure 60 psig, design pressure from 300 psig, test pressure 1.5 times, safety factor at least 5:1 · scope of repair, dome strength from 800 pounds vertical load · obligation to pickle, passivate and pressure-test · scrapping and quarantine criteria | Association publication, free as a PDF, technically solid |
| Brewers Association A Practical Approach to Refillable Kegs, CBC Online 2020 | Overhaul of spear and down tube after 7 to 8 years · retaining rings always renewed · tightening torques approx. 75 Nm and 47 Nm · valve lifts 8 mm and max. approx. 6 mm · headspace values · thermal expansion · six fault patterns on the spear | Association publication, speaker from the sales side |
| Brewers Association Keg Scrapping · Keg Repatriation FAQ · Steel, Not Steal | A deposit transfers no ownership · origin of kegs at the scrap dealer · freight dilemma with returns · keg loss costs 0.46 to 1.37 USD per barrel (2015, USA) | Association publication, US context – not transferable to Germany |
| BLEFA GmbH & Co. KG 30-year warranty | 30 years on service life, weld seam tightness and corrosion protection – condition: maintenance every 7 years with 100 % visual inspection of the outer seams, 100 % pressure test up to 6 bar, straightening of neck and necks | Manufacturer's undertaking, publicly documented |
| Getränkeindustrie 8/2024 K. Spiegelmacher, Keg-Inspektion heute | Identification features and machine recognition: laser serial number, bar and matrix code, RFID · cycle times 6 to 10 seconds per keg · classification of six coupler types · damage and leak detection | Technical article by a plant manufacturer – interest-driven, precise in content |
| treeze Ltd. (2013) Wyss/Frischknecht, Simplified LCA of beverage kegs, for Franke Blefa | Break-even point of the steel keg against single-use plastic at 15 to 20 cycles depending on the indicator · packaging weights 6.00 kg against 1.00 to 1.05 kg | not ISO-compliant Simplified assessment commissioned by a keg manufacturer. The authors themselves describe the plastic figures as unconfirmed. Text and illustration are subject to copyright |
| DGUV / BG RCI Information 213-062, Druckprüfungen von Druckbehältern und Rohrleitungen, April 2012 | Priority of the hydrostatic pressure test · ratio of the strain energies of air to water roughly 14,000 to 1 · five per cent of air bubbles in the test water raise the energy to about seven hundred times | Association paper close to the rulebooks Refers to BetrSichV, TRBS 2141, AD 2000 code of practice HP 30 and DIN EN 13445/13480 |
| Spear reconditioning Type overview from a specialist workshop | Body dimensions per type (EU Sankey (S-type) and US Sankey spear (D-type) not adopted – by design neither has a body above the neck) · Working pressure beer spears up to 3 bar, soft-drink spear up to 7 bar · Type designations and locking variants including cam marking · Fine thread 2″ × 14 TPI with approx. 10 turns, coarse thread 3 to 5 turns | freely accessible type overview with body dimensions per type |
| Keg pool operator, USA published cleaning standard | Caustic 1.5 to 2.0 % v/v · phosphoric acid 0.25 to max. 0.4 % v/v · steam holding time 60 s · condensate limits | Keg pool operator – interest-driven, unusually specific |
Peer-reviewed science
Considerably less than one would expect.
| Source | What we use from it | Classification |
|---|---|---|
| Martin et al. (2022) Circular Economy and Sustainability 2(3) | Climate advantage of the steel keg from 38 uses · break-even against plastic at around 245 km transport distance · the 80 uses in 14 years are expressly a model assumption there, not a measurement | independently peer-reviewed Open Access. The only independent life-cycle assessment on the subject – the second one we found comes from a manufacturer |
| Ooyama et al. (2025) Sustainability 17(24) | Switching half of sales to draught beer: −44 % CO₂ equivalent, −11 % costs | peer-reviewed, no third-party funding Single case study, Japan |
| Nettesheim et al. (2024) J. of Transport and Supply Chain Management 18 | Real-time tracking of reusable kegs reduces the fleet required and shortens cycle times and collection routes | peer-reviewed University of Siegen, Open Access |
| TU München Forschungszentrum Weihenstephan, short report | Summer damage on slim kegs: the cause is the headspace geometry, not overfilling – the carbon dioxide content was normal | Not publicly published |
| Marrucci et al. (2024) Science of The Total Environment 948 | States around 90 % lower environmental impact for kegs than for glass and cans | we do not use it A clear outlier against every other life-cycle assessment. We do not cite the figure as evidence |
Our own figures
Two things on this website come from our own operation and are expressly marked wherever they appear:
- The age observation. In our refurbishment, kegs with years of manufacture from the eighties and nineties are everyday business. That is not a study but an observation across thousands of kegs.
- The identical construction of type A and type G. Internally the same spear, externally the triangular body. Spare parts interchangeable, couplers not.
- The construction of the US Sankey spear (D-type). It sits inside the neck and finishes flush with it, so it has no body above the neck and therefore no comparable body diameter. It exists with a standard thread and without a thread – in the threadless version it is sunk into the neck and held with a retaining ring. Dimensions of the threadless version: 53.7 mm across the locking lugs, immersed body 50.2 mm, upper opening 38.9 mm. Workshop figures, based on production drawings from our own records.
- The pressure figures on a beer keg. Operating pressure no more than 3.5 bar (embossed on the keg), test pressure at the manufacturer and during inspections up to 10 bar, burst disc releasing at 30 to 35 bar depending on the maker, ± 5 each, fitted underneath on the bottom dome. Workshop figures, not a standard.
- Our prices. They are not listed here but in the shop: small quantities go straight through it, larger quantities we quote on request.
If you doubt a figure
Then write to us. If you are right, we correct it. Get in touch