The bodies and bonnets (the top outer part, or hood) of most small single stage gas regulators are made of die cast zinc alloy.
Zinc is a silvery metal element which is tough, durable, non-sparking and resists corrosion. It is often combined with other metals such as copper and aluminium to form an alloy (mixture).
There are many combinations of zinc alloy but they are all ideal for die casting. They can be poured into any shape of mould, are very strong, can be cast very thinly and melt at relatively low temperatures, which means production costs are lower.
They can also be coated with many different finishes to make the products look like stainless steel, gold, brass or even leather.
Brass
Many regulator connectors are made of brass, which is a copper and zinc alloy. Brass has many uses as it’s long-lasting, anti-corrosive, looks attractive and is easy to shape during the manufacturing process.
Brass is also used in many high pressure regulator bodies owing to its strength. In addition, it’s non-sparking, so won’t cause an explosion if it comes into contact with flammable gases.
Stainless steel
Stainless steel is made by mixing steel with chromium, which makes it more resistant to rust and tarnishing.
It’s an expensive and high quality material which is often used for the bodies and connectors of laboratory regulators, particularly when testing certain pure gases that aren’t compatible with brass. Some regulator diaphragms are also made of stainless steel.
Aluminium
Some regulator bodies and bonnets are made of aluminium, which is a lightweight, silvery white, non-magnetic metal.
It is a lower cost alternative to stainless steel, and is also used where a heavy regulator could be a problem, such as in a laboratory. However, it’s not as durable as stainless steel.
Nitrile rubber
The diaphragms and sealing washers of most single stage regulators are made of nitrile rubber. This is a synthetic material that comes in many variations. It is more resistant to oil and gas corrosion than pure rubber.
Plastic
The levers, handles and control knobs of most regulators are made of plastic, which is lightweight, cost effective and versatile as it can be moulded to many different shapes.