Dissecting: Composite Cylinder Parts

Dissecting: Composite Cylinder Parts

One of the frequent questions we are asked at Aburi is “what are the composite cylinder parts?”. Today we have decided to answer all you need to know about the fibreglass cylinders components.

The short answer is: the cylinder has 3 parts, the cylinder itself (or belly), the valve and the casing.  No Secret! 

However, this usually would not satisfy our most meticulous customers. Therefore a composite cylinder is made of the following parts:

1) The in liner: Is a blow moulded HDPE container to hold the liquid gas inside

2) The pressure vessel: Made out of glass fibre winding with Epoxy, helically wound on the inner bottle. Together this provides the ultimate strength to the cylinder.

Fibre winding with a bonding Epoxy is the most crucial part of the composite cylinders. They are crucial because the winding has a direct impact on the strength of the cylinder as also bursting pressure.

3) The Bung Housing:  To make it suitable to use valves

There are two types of bung housing being used by the main manufacturers in the composite cylinder business

  • Brass Bung Housing: Are lighter in nature (by weight) and also are lighter on use. Being brass, a softer material cannot take higher torque. 
  • Steel Bung Housing: Steel Bung are heavier and due to their hardness can take higher torque.

Due to the different types of valves being used by gas distributors, steel bung housing is preferable. As Brass Bung is a softer material, the max torqueing possible is about 120 Nm and gas distributors have to use a valve that is non-standard. Some manufactures prefer this to retain the customers, however, this results in a logistic issue of carrying not only two different valves, but also educating the online worker at the gas filling station to take notice and use the correct valve for the right cylinder, which could result in a problem, if the incorrect valve is used.

4) Outer casing: The ergonomically designed casing’s basic function is to ensure that the pressure vessel is safe guarded from severe drops, and to prevent direct exposure to metal objects that can result in the fibre wound container to get flaws, and for ease of carrying and handling.

Finally, the aesthetics are decided between the buyer and seller. The buyer usually is a gas distributor and the seller is the composite cylinder manufacturer. Normally, the gas distributor would only need to brand the cylinder with the company’s colours, logo and contact details.

We hope you enjoyed the blogpost and to learn more about this great product, composite LPG cylinder, click here!