Free bench guide ·
prodive-shop.com
prodive-shop.com
Scuba Regulator Service & O-Ring Checklist
A printable step-by-step guide for DIY regulator maintenance, plus a quick reference for the most common O-ring sizes. Print it, tick the boxes at the bench, and keep your gear sealed and breathing right.
1 · Before you start
- Have the manufacturer's service manual to hand
- Clean, well-lit workspace + soft cloth
- Correct service kit & fresh O-rings for your model
- O-ring pick, pin spanner, soft brushes
- Silicone grease (for O-rings) & an IP gauge
- Depressurise & disconnect from the cylinder
2 · Disassembly
- Photograph each step before you take it apart
- Lay parts out in order of removal
- 1st stage: remove hoses, note port O-rings
- 2nd stage: open cover, remove diaphragm & poppet
- Keep small parts in a tray so nothing walks off
3 · Inspect & clean
- Check sealing surfaces for scratches or corrosion
- Clean parts; rinse and dry fully
- Inspect the filter — replace if stained/clogged
- Check the HP seat & poppet for wear
4 · Replace every O-ring
- Never reuse old O-rings — fit fresh ones
- Match size and cross-section (see chart)
- Light smear of silicone grease on each O-ring
- Seat evenly — no twists or pinches
- Right material for the job (see note below)
5 · Reassemble & test
- Reassemble in reverse, to manual torque specs
- Set/check intermediate pressure (IP) with gauge
- Leave pressurised 1–2h — watch for IP creep
- Check 2nd stage cracking effort & free-flow
- Submerge & check for bubbles before you dive it
- Breathe-test in shallow water first
Material quick guide
- NBR / Nitrile — standard air use
- Viton / FKM — high-O₂ / nitrox & heat
- EPDM — some O₂-service applications
Common regulator O-ring sizes (AS568)
| Location | Size | Typical dimensions |
|---|---|---|
| 2nd stage swivel / hose end | -010 | 6.07 × 1.78 mm |
| LP / MP hose & port connections (1st stage) | -011 | 7.65 × 1.78 mm |
| HP hose & port connections (1st stage) | -012 | 9.25 × 1.78 mm |
| Yoke / A-clamp tank valve (thin) | -014 | 12.42 × 1.78 mm |
| DIN valve & yoke (thick) | -112 | 12.37 × 2.62 mm |
| Small DIN valve | -111 | 10.82 × 2.62 mm |
Sizes vary by manufacturer — always confirm against your own parts. Not sure which one you're holding? Measure it in the tool below.
Safety first: Regulator servicing affects a life-support device. This checklist is a general aid, not a substitute for your regulator's official service manual or proper training. If in doubt, have the work done or checked by a qualified technician. Always leak- and breathe-test before diving.
Identify any scuba O-ring in a minute: