Tri-Clamp Pressure Ratings by Clamp Style and Size

In a tri-clamp system the clamp and gasket joint sets the pressure limit long before the tube does.

DocumentREF-CL-01
SeriesEngineering Reference
Revision2026.1
Issued24 September 2026
Maximum service pressure for 304 and 316 stainless tri-clamp connections by clamp style and size. Each cell shows psig at 70°F (21°C) / 250°F (121°C). These are joint ratings from hydrostatic tests with standard Buna-N gaskets, correct assembly and no shock pressure, not clamp body ratings.

Service ratings, psig at 70°F (21°C) / 250°F (121°C)

Size Single pin 13MHHM Double pin 13MHHMD Heavy duty 13MHHM-H 3-piece 13MHHS High pressure 13MHP Snap-lock EG13
1/2" 1500/1200 - 1500/1200 - 1500/1200 -
3/4" 1500/1200 - 1500/1200 - 1500/1200 -
1" 500/250 500/250 500/250 600/300 1500/1200 150/125
1-1/2" 500/250 500/250 500/250 600/300 1500/1200 150/125
2" 450/250 450/250 450/250 550/275 1000/800 150/125
2-1/2" 400/200 400/200 400/200 450/225 1000/800 150/125
3" 350/150 350/150 350/150 350/160 1000/800 150/125
4" 200/125 200/125 200/125 250/150 800/600 150/125
5" 175/100 - 175/100 - - -
6" 150/75 - 150/75 - 300/200 -
8" 100/50 - 100/50 - 250/150 -
10" 40/30 - 40/30 - - -
12" 30/25 - 30/25 - 150/100 -

A dash means that style is not listed in that size. 1/2 and 3/4 inch high pressure values from sanitaryfittings.us, which matches GVC on every other 13MHP size.

T-bolt clamp, 304 SS, psig at 70°F (21°C)

Size 1 to 1.5" 2" 2.5" 3" 4" 6" 8" 10" 12"
psig 500 350 300 200 100 75 50 40 30

How to use these ratings

  • Temperature. From 70°F (21°C) to 250°F (121°C) the rating drops 20 percent (high pressure clamp, 1 to 4 inch) to 57 percent (single pin, 3 inch). No values are published between the two columns, so use the 250°F value for anything above room temperature.
  • The gasket governs at temperature and at the cold end. Buna-N is rated to about 250°F (121°C) and only to about -30°F (-34°C) at the cold end. Hydrocarbon systems run to -65°C (-85°F), where only PTFE gaskets remain inside their rated range. See REF-CM-01.
  • N.B. Oler systems. The 6 inch high pressure clamp is 300 psig at 70°F (21°C) and 200 psig at 250°F (121°C). That is why the 6 inch tube in shell and filter housings carry a 250 psi rating limited by the clamps, not the tube.
  • Verify before relying on a number. Values were transcribed from the GVC Direct rating sheet. Spot check against the maker's current sheet for your exact clamp.

Sources. GVC Direct, Tri-Clamp Connection Service Ratings for 304 and 316 SS Connections; GVC product pages for clamp styles and T-bolt ratings. Cross-check: sanitaryfittings.us, Tri-Clamp Fittings Burst Pressure and Temperature.

Questions about your system? Call the shop at 541-330-6409, Monday to Thursday, 8 to 4 Pacific, or email info@nboler.com.
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