5 Year Rubber Replacement

Conjecture:

Your new hose (& other rubber components) will be just fine.

Rubber that has not been exposed to sunlight, repetitive movement, high heat (such as engine bay) and hydrocarbons (petrol, oil,etc) will last, almost, indefinitely.

The reason for replacing (at the conservative 5 year interval) your engine & fuel supply system rubber, is that it does get exposed to the above conditions and should they fail, there is not the option to pull over & call the repair service, unlike a ground based vehicle, .

So conservative is the 5 year replacement interval, I find that, if you start with quality materials (eg Gates hoses) they are still in such good condition, when replaced, they can be repurpose for ground based equipment eg mowers or use "rings" cut of the old hoses for abrasion control.

Rubber hose manufacturers publish their products shelf life.  Parker for instance lists their general purpose rubber fuel hose as having a 7 year shelf life, with 3 additional years granted if the hose is stored in accordance with ISO 2230 standards.  Their Teflon hoses have an unlimited shelf life.  

Even accounting for proper storage, the shelf life is 10 years, whether placed into service or not.  A 6-year old hose only leaves you with 4 years of service as per manufacturer recommendations.  I don’t accept hoses older than 2 years.  

Jeff Blakeslee wrote:

Rubber hose manufacturers publish their products shelf life.  Parker for instance lists their general purpose rubber fuel hose as having a 7 year shelf life, with 3 additional years granted if the hose is stored in accordance with ISO 2230 standards.  Their Teflon hoses have an unlimited shelf life.  

Even accounting for proper storage, the shelf life is 10 years, whether placed into service or not.  A 6-year old hose only leaves you with 4 years of service as per manufacturer recommendations.  I don’t accept hoses older than 2 years.  

So how does the customer find the production date and the shelf life?

Hi Sean,

There is a date code stamped on the hose at regular intervals, but the format is not standardized across the industry.  Gates, for instance, dates their hoses as MMDDYY such that 112223 would be November 22, 2023.  This document discusses Gates date coding and shelf life. The shelf life is a bit vague.  

https://www.gatesaustralia.com.au/products/industrial-hose-couplings-and-equipment/hose-date-codes

Parker dates their hoses by quarter and year, such that a hose made in the second quarter of 2022 would be dated 2Q 2022.  This document from Parker Hose discusses shelf life on the last page under the section “6.0 Hose Storage”. They are very specific about the shelf life.

https://www.parker.com/content/dam/Parker-com/Literature/Parflex/Parker-Safety-Guide.pdf

Within the aviation industry, rubber hose is generally considered to have a 10 year shelf life, inclusive of the time it’s in service. However, where a time limit is not stipulated by the aircraft or engine manufacturer, many hoses are replaced “on condition” so are in service longer.  

Hi Jeff,

Great information - thanks.

I use Gates hoses where ever possible and Rotax where not. I have never known about this coding for manufacture date or their recommended shelf life.

I would point out that in my experience (Rotax only about 10-12 years, 55 automotive) the Rotax 5 year replacement advice (which I support & adhere too) is ultra conservative, as it should be.

My evidence for saying ultra conservative is -

I have had automotive rubbers (cooling/oil/air) last 30 years plus without failing - only replaced when some unrelated (to in service performance) event occurs.

My 5 year old Rotax rubbers are all still flexible (subjectively slightly less than when new) without any visual sign of deterioration

If my observations are correct, I would suggest that concerns over shelf life, while valid, should not be overemphasised. In my view using quality products, with a readily available documented QA regime (as with Gates) is a must. Those who purchase products, without some assurance, as to their fitness for purpose, are unnecessarily risking  themselves, passengers & public for the sake of a very few dollars. 

Having said the above, in future, I will be checking out the date codes.