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iain-hsm · 10th March 2006, 12:23

Quote: (Originally Posted by Rikard Bengtsson)

Hi
Im wondering if anyone have tested this kind of LP-hoses and fittings from Swagelok ???? Multipurpose Push-On Hose (PB Series)

In a word yes we have tested this type of hose IMHO I don’t think this is a good choice for oxygen there is a much better option with the SAE 100 R7 and stainless crimped ends. Using nitrile is the poorest option, Swagelok were well advised to suggest changing the hose each year. In oxygen nitrile is a pretty poor material and will age quickly become brittle and crack.

Also consider that push on fitting are not allowed in divers breathing hoses offshore or with military as not an effective closure for critical use. Re-useable type fittings for commercial divers umbilical and bail out whips were banned some 20 years ago.

The other consideration for breathing hose is the fitting pull test (push ons failed this) and a tension test were a sample hose is loaded with a 50Kg weight over a 2 inch tube for 24 hours, the hose is then tested for elongation and deflection by length measurement and by shooting a steel ball through the hose. If it passes this the sample is then subjected to a hydraulic burst test within 12 hours. Agreed not all “divers” equipment is tested to this standard showing once again the difference between standards for Diving and Scuba. Iain Middlebrook

10th March 2006, 12:23	#20 (permalink)
iain-hsm Custom Title Allowed! Current Rebreather/s: MK 15.X Other CCR Other SCR Other Rebreather/s: Other CCR Other SCR Join Date: Mar 2005 Location: Loughborough England uk Posts: 347	Re: Has anyone used this swagelok hoses ??? Quote: (Originally Posted by Rikard Bengtsson) Hi Im wondering if anyone have tested this kind of LP-hoses and fittings from Swagelok ???? Multipurpose Push-On Hose (PB Series) In a word yes we have tested this type of hose IMHO I don’t think this is a good choice for oxygen there is a much better option with the SAE 100 R7 and stainless crimped ends. Using nitrile is the poorest option, Swagelok were well advised to suggest changing the hose each year. In oxygen nitrile is a pretty poor material and will age quickly become brittle and crack. Also consider that push on fitting are not allowed in divers breathing hoses offshore or with military as not an effective closure for critical use. Re-useable type fittings for commercial divers umbilical and bail out whips were banned some 20 years ago. The other consideration for breathing hose is the fitting pull test (push ons failed this) and a tension test were a sample hose is loaded with a 50Kg weight over a 2 inch tube for 24 hours, the hose is then tested for elongation and deflection by length measurement and by shooting a steel ball through the hose. If it passes this the sample is then subjected to a hydraulic burst test within 12 hours. Agreed not all “divers” equipment is tested to this standard showing once again the difference between standards for Diving and Scuba. Iain Middlebrook
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