Check your lifejackets at home? Here's something to think about

[skyflyer]

STP is 15c and 1013.25 mb IIRC?

 

[Hydrozoan]

STP is 15c and 1013.25 mb IIRC?

The IUPAC Gold Book says (http://goldbook.iupac.org/S05910.html) that IUPAC recommends that the use of 1 atm as standard pressure (equivalent to 1.01325 x10^5 Pa, or your 1013.25 mb) should be discontinued. They now recommend 10^5 Pa exactly! But the standard temperature is still 273.15K (0 deg C).

 

[skyflyer]

seems i was thinking of the International Standard Atmosphere, not sure what the different applications are for that vs STP

 

[Hydrozoan]

seems i was thinking of the International Standard Atmosphere, not sure what the different applications are for that vs STP

I'd be a bit surprised if you were: according to Wiki that is a model of the atmosphere with different pressure, temperature, density, and viscosity assigned to various layers. [EDIT: Sorry! I see that at zero elevation the International Standard Atmosphere values are 1.01325 bar and 288.15 K, or 15.15 deg C, so that ties in with what you said and the first of what follows ...]

I think you are more likely to have had in mind the International Standard Metric Conditions for natural gas, which are 15 deg C and 101.325 kPa, or 1 atm.

Or less likely the NIST (formerly NBS) standard, also called Normal Temperature and Pressure (NTP) of 20 deg C and 1 atm - or the Standard Ambient Temperature and Pressure (SATP) which is 25 deg C and 100kPa.

All very confusing - and you got me worried because I used both STP and NTP, albeit many moons ago. But the molar volume of an ideal gas of 22.4 litres, which I used, is I believe at STP.

 

[laika]

How about asking the manufacture what is the design pressure and what is the pressure that a gas canister will deliver.

They may also be able to give you an idea of their age if you still have the serial numbers.

Good idea which I'll also give a go but I've tried speaking to Mullion before when trying to obtain a replacement crotch strap and they were beyond abysmal. .

Tried it. Gave a serial number and asked if they could give me an idea of the age of the lifejacket and the rated inflation pressure. The reply?

Our lifejackets should all only be tested by one of our approved service agents. You can find your nearest service centre vis the following weblink:

I thanked them very much for this information and repeated the questions saying that I was interested in the age to asses whether to service or replace. No reply. That was 2 weeks ago.

Don't buy Mullion if you value customer service