Camlock Pressure Rating Chart: What Each Coupling Actually Holds
Camlocks are rated by working pressure, and the rating drops as the size grows. A 2” aluminum coupling holds 200 psi; the same coupling at 6” holds 60 psi. That’s not a defect — the cam arms and groove carry the same load across a bigger bore, so the pressure has to come down.
This chart is the one buyers ask for most. Bookmark it before you order.
Working Pressure by Material and Size
Ratings below are for standard A-A-59326D profile couplings with new, correctly seated gaskets, at ambient temperature.
| Size | Aluminum | Stainless 304/316 | Brass | Polypropylene |
|---|---|---|---|---|
| 1/2” – 2” | 200 psi | 250 psi | 250 psi | 150 psi |
| 3” | 125 psi | 150 psi | 150 psi | 100 psi |
| 4” | 110 psi | 130 psi | 120 psi | 100 psi |
| 6” | 60 psi | 70 psi | — | — |
How Temperature Changes the Rating
All four materials derate at temperature. As a rule of thumb:
- Aluminum and brass: full rating to roughly +80°C; derate ~0.5% per °C above that.
- Stainless steel: holds its rating to +150°C with EPDM gaskets; beyond that the gasket — not the metal — becomes the limit.
- Polypropylene: rated at +20°C. At +60°C expect roughly half the listed pressure; PP softens quickly as it heats.
If your line runs hot, quote the temperature along with the fluid. The cheap mistake is picking the material for the fluid and forgetting the temperature.
Vacuum and Surge
Two conditions the chart doesn’t cover:
- Vacuum duty: camlocks are not vacuum-rated by default. Light vacuum (under ~10” Hg) is usually fine with a fresh gasket; deeper vacuum needs a clamped or flanged connection.
- Surge/spike: the figures above are working pressure, not burst. Designers typically add a 3:1 safety margin against spikes, and camlocks must never be used above rated working pressure, even briefly.
What Puts a Camlock Over Its Rating
Most field failures are not the coupling’s fault:
- Wrong gasket material softening or hardening in the service fluid.
- Worn cams or lever arms that no longer clamp square.
- Mixing sizes — a 3” adapter forced into a 2” coupler concentrates load on the cams.
- Dented grooves from dragging hose ends on the ground.
Inspect both halves before every connection, and replace gaskets at the first sign of cracking or flattening.
Never Use Camlocks For
- Compressed air or steam. Camlocks are not rated for gas service — use a proper air/steam coupling.
- High-pressure hydraulic lines above their rating. Hydraulics belong to JIC, BSP or flange connections.
- Aromatic hydrocarbons with EPDM gaskets — the gasket dissolves. Use NBR or Viton.
FAQ
Is 200 psi enough for water transfer? For irrigation, dewatering and most transfer lines, yes — 200 psi at 1/2”-2” covers virtually every water application. Municipal or fire lines with higher surge pressures should be engineered explicitly.
Do Dixon and CamlockPro couplings have the same ratings? Both follow the A-A-59326D profile. Ratings vary slightly by manufacturer and gasket spec — check the specific product data sheet rather than assuming.
Can I test my coupling’s pressure? Hydrostatic testing is standard for assemblies we build. Field-testing a bare coupling above its rating is how couplings and people get hurt — don’t.
Ratings are reference values from public industry sources, pending factory verification. Always confirm against the product data sheet for your exact size, material and gasket combination.