What is the Correct Air Pressure for a Hypalon Rib

[jackreno]

Was not told the pressure when I bought my rib so I have no idea, I guess around 3.5 to 4 psi ?

Its a 2007 Novurania 335

[willk]

Originally Posted by jackreno

Was not told the pressure when I bought my rib so I have no idea, I guess around 3.5 to 4 psi ?

Good lord, no! Beginning at 1.5psi - maybe 2 if you're feeling lucky! Mind the sun too....

[dave3235]

Originally Posted by willk

Good lord, no! Beginning at 1.5psi - maybe 2 if you're feeling lucky! Mind the sun too....

Hi

I would put .25 bar in them as most tubes inflate to this.Have you tried to Google for the spec sheet..

[Max...]

As willk said. You might be getting muddled up with SIB pressures which are much higher (typically 3.4psi max). On a SIB the tube is a structural element, on a RIB the hull is the structure and lower tube pressures allow the tubes to conform more easily to the sea for improved cushioning/ride/handling.

[willk]

Originally Posted by dave3235

Hi

I would put .25 bar in them as most tubes inflate to this.Have you tried to Google for the spec sheet..

3.6psi? Generally those pressures are used in SIBs. Most RIBs run around 1.3 - 1.7psi. 2 psi is rock hard.

As the OP doesn't require structural support from his RIB tubes, I'd suggest exercising caution and inflating to well under 2psi first. The other end of the spectrum is running tubes too soft - anything that can be pushed in with a finger is IMO, a tad too soft. The problems occur when soft tubes are in contact with fast moving water - the ripple effect on the tubes can be quite violent and cause rubber trim and seam damage.

[dave3235]

Originally Posted by Max...

As willk said. You might be getting muddled up with SIB pressures which are much higher (typically 3.4psi max). On a SIB the tube is a structural element, on a RIB the hull is the structure and lower tube pressures allow the tubes to conform more easily to the sea for improved cushioning/ride/handling.

Hi

My apoligies , if you do a search on Google stuff does come up about this boat needs a bit more digging.I would of pasted a link but don't know how to from my phone.

[Pikey Dave]

Ribcraft specify 2.5psi max for their tubes


.....sh1t happens.......

[office888]

Running a RIB underinflated at high speeds will cause the stern transverse seam to blow out...

I generally treat 3.5 psi / 240mb as my rule of thumb.

[cgoing]

Below is straight from the Novurania owner's manual:


RECOMMENDED PRESSURE 3 PSI
Inflate all tube compartments to maximum pressure of 3 PSI. If a pressure gauge is not
available, check by depressing the tube with your finger. When the tube cannot be
depressed by finger pressure, the approximate working pressure has been reacted.
CAUTION
The foot pump provided with your Novurania will not allow over-inflation of the tubes.
NEVER use dive tanks, air compressor etc., to inflate tubes; over inflation can occur
causing damage to the tubes and seams. Under-Inflation can cause excessive stress on
the tubes and hull, always maintain proper inflation pressure while operating your boat.
IMPORTANT
If the boat will be exposed to direct sunlight for a long period of time, slightly deflate the
tubes to compensate for expansion due to heat.

[jackreno]

Thanks cgoing, I guess I was not to far off on my estimate, I do have a Sib and it said around 4 psi but did not know the Rib pressure, 2 psi as mention above seems to soft.

[jackreno]

Originally Posted by dave3235

Hi

I would put .25 bar in them as most tubes inflate to this.Have you tried to Google for the spec sheet..

.25 bar = 3.5 psi

[jackreno]

Originally Posted by jackreno

.25 bar = 3.5 psi

What I needed to add here is 3.5 psi seems to be just about right on the feel of my Rib tubes, not to hard either, I keep my Sib at 4.5 psi and it has done this for almost 2 years without a seam failure, anything less in pressure it runs slower.

[ShinyShoe]

Do you use the same gauge each time? If you ever change gauge I'd be cautious. That feels to be like your gauge calibration might be off a touch... 4.5psi is a lot...

[bmb779]

My Waveline Rib runs at 3.6 psi or .25bar.