The bonnet, also known as a hood, is the upper outer layer of the regulator.
It sits on top of the body, which is the lower part of the regulator and has the handle, valve and hose connector attached.
Lever and release button
There are many types of clip-on regulator. Modern versions often include a lever which you twist anti-clockwise to a vertical position to turn on the gas, and clockwise back to a horizontal position to turn it off.
You push the release button inwards to remove the regulator from the cylinder. For extra safety, the button won’t move unless the regulator has been turned off.
Regulator outlet nozzle
The outlet nozzle, also known as a spigot, is the part that connects to the hose and carries the gas from the regulator to the appliance. It includes ridges which help hold the hose clips securely in place.
The nozzle size is measured by its diameter – normally 8mm and 12mm. Several sizes are available, depending on the type of gas cylinder. If you have to buy a hose separately, make sure it’s the same internal diameter as the external diameter of the nozzle.
Regulator valve size
The valve size is measured in millimetres according to its diameter. Three sizes are available, depending on the make and type of gas cylinder:
20mm – butane
21mm – butane
27mm – patio gas
Always make sure the valve on the cylinder is the same size as on the regulator, and never try and force the wrong sized regulator on to a cylinder as you could damage the valve.
Locking collar
The locking collar grips tightly around the outside of the valve to stop the regulator moving up and down once it has been attached.
Regulator valve
The valve controls the flow of gas from the cylinder into the regulator by opening and closing.
It may, however, also open when pressure in the cylinder is too high, allowing gas to bypass the regulator and vent to the atmosphere.
Regulator sealing washer
The sealing washer around the valve is there to stop gas leaking out of the join between the regulator and the cylinder.
It’s usually made of oil-resistant synthetic rubber, although pure rubber is also sometimes used.