What is recommended pressure?

[Marcin]

Hi.

Maybe it’s stupid question (because everybody knows answer), but I have to ask. What is pressure inside packraft chamber?I found only information about mouth inflation – does it mean that internal pressur not exceed 40-45mbar (0,6 psi)?

Topic

[gregkn]

Hi,

 

At the following, links I understand that alpackaraft, advice no more than 2.5 psi. Fabric and construction similar to any DIY project. So why not exceeding 1 psi, to 2psi or more if I can carry a small pump and achieve a stiffer and better responding packraft? Is it a matter of the heat welding seams or  fabric?

 

Thanks,

 

Greg

 

https://www.alpackaraft.com/products/k-pump-mini

 

 

 

 

[Bruce]

Marcin, Yes, packraft inflation is limited to lung pressure, at or less than one psi. In contrast, I believe a full size NRS 18′ heavy duty raft is inflated to 2.5 psi, much higher pressure than any packraft should be inflated.

It is an interesting question, and I have just acquired a low pressure gauge to fit my NRS barrel pump so I can pressure test my seam weld quality. Gotta be fun blowing up sample tube sections?? Not having begun my tests, I suspect seams may hold several psi. However, I don’t intend to operate my rafts at higher pressure because I believe the 210D fabric is more likely to rupture on contact with a sharp object (stick, rock) as you increase pressure. More importantly, the goal of a packraft – light and small enough to backpack – is not compatible with carrying a pump.

I’m not set up to hot air weld, or I’d pressure test sample tube section from the double sided 1000D fabric. That would be a “mil-spec” raft! Ha!

Larger designs, like the tandem, use larger diameter tubes, increasing the “SI” (square inches) in psi. The one psi limit is a key factor in the design considerations. You can’t expect 210D fabric to work like RF welded hypalon or heavy vinyl 18′ oar rafts.  Fortunately.

I was planing on pressure testing next winter. Sorry, gone boating.

Bruce

Fairbanks

[Author]

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