gas fittings for camping

Introduction

LPG stands for Liquefied Petroleum Gas and this may refer to propane (as it usually is in Australia), butane or a mixture of both
n-butane has a boiling point of -0.5degC and at 21deg is stored in cylinders or cartridges at 215kPa
iso-butane has a boiling point of -11.7degC and at 21deg is stored in cylinders or cartridges at 310kPa
propane has a boiling point of -42degC and at 21deg is stored in cylinders or cartridges at 860kPa hence requires extra strong and heavy cylinders but is better than butane in sub-zero temperatures
natural gas is methane and appliances operate at much lower pressures than LPG (1.1kPa vs 2.75kPa)

whilst you can use appliances with different fitting to the bottle via adapters such as 3/8”BSP–POL, these add extra connections and thus extra risk of gas leaks - so check the fitting before use
you cannot in any instance join two gas hoses together as this can be dangerous
you cannot lengthen the hose of a high-pressure stove but you can lengthen the hose of a low-pressure stove
some principles regarding LPG gas cylinders
- it is not legal to refill a cylinder that is more than 10yrs old unless you have it re-certified
- they must be stored upright and out of direct sun
- avoid storing them on your vehicle in an impact zone - most transport them on the roof rack - perhaps tied down in a milk crate - check your local regulations!
- they are heavy a 1.25kg gas bottle actually weighs around 4kg when full
- they are hard to judge how empty they are without weighing them
- the pressure inside them is generally high at 600-900kPa
  - a pressure regulator is usually needed to attach to most appliances and this reduces pressure to a more manageable and controlled 2.75kPa
    - caravans often have this regulator at the gas cylinder and thus you don't need to add extra regulators into the system for each appliance connected to the gas line - these must be fitted by licensed gas fitters.
    - some appliances have an internal regulator such as the Mr Buddy camping heater, but these also need a fuel filter to be used at the heater end of the hose

LPG gas cylinders
- are usually stamped with a TARE weight which is their weight when empty
- a “4kg” gas cylinder usually has a TARE weight of 4.5–6.6 kg and can contain 3.7kg of gas when full so will weigh TARE + 3.7kg when full

BEFORE lighting a gas appliance and also after turning off the gas cylinder, ALWAYS check there are no leaks using a gas leak detectors
- failure to do so may result in severe burns due to flames from the leak source, or worse, a gas explosion (especially if in a poorly ventilated enclosed space)
LPG gas cylinders must not be transported long distances inside a vehicle
- it is illegal because any leak (eg. valve moved to open during transport) can cause a major explosion!
- the ideal location is secured on a roof rack or possibly in a roof pod - in either case they must be upright and preferably protected from full sun

this is used on older 4-9kg cylinders such as those at service stations, Swap'n'Go, etc
has a counter-intuitive thread rotation and thread is internal on the gas cylinder (ie. female) requiring a male POL hose

LCC27 (Leisure Cylinder Connection) is a newer Australian safety standard for LPG gas cylinders introduced in 2021 and identifiable by a black valve knob and has an external thread as well as an internal thread like the older POL gas cylinders
used on newer 4-9kg LPG gas cylinders such as those at service stations, Swap'n'Go, etc
designed to be backward-compatible with older POL hoses
safer design as thread is no longer counter-intuitive and is less likely to leak - the older POL could have valve opened and leak even if nothing was attached
- has an integrated ‘check-valve’ that does not allow gas to flow when the valve is opened, unless an appliance is securely attached to the cylinder
- a gas seal achieved at the connection point prior to the check-valve being opened by the fitting of the appliance, irrespective of how tightly the ‘nut’ has been fastened by the user
- external right-handed ACME thread
- a large plastic ‘nut’ designed to soften in the event of a fire at or near the cylinder. This allows the appliance fitting to eject, in turn triggering the check-valve to stop gas flow
you can use POL hoses on a LCC27 gas bottle but you cannot use a LLL27 hose on a POL gas bottle
see https://www.snowys.com.au/blog/pol-and-new-lcc27-gas-fitting/

proprietary fitting used on Primus bottles that has an internal fitting that only allows gas to flow once the fitting is fully inserted into the cylinder

BOM fitting 465g propane cartridges
- designed for BOM fittings on portable appliances
- eg. Mr Buddy Heater
threaded puncture cartridges
- eg. Jetboil JetPower (propane/isobutane mix)
- eg. Companion butane/propane mix Pro-Fuel cartridge
aerosol can style butane canisters
- eg. Companion butane/propane mix Pro-Fuel cartridge

hiking gas cartridges are made light with thin walls and use a MIX of isobutane and propane - DO NOT refill these with propane only as they may explode as propane has much higher vapour pressures and requires a much stronger cartridge!

used to connect to BOM 465g propane canisters eg. Coleman, Companion, Gasmate, Oztrail
aka 1“-20 UNEF (Unified National Extra Fine) thread (1 inch outer diameter, 20 threads per inch)
can be used with LPG cylinders via BOM to POL and BOM to 3/8″ LH adapters HOWEVER it is recommended to use a “fuel filter” as well otherwise you may have issues with your Mr Buddy heater or similar appliance not running