brass ball valve

Brass Ball Valve

A brass ball valve uses brass as its material.

Brass is any alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties. In comparison, bronze is principally an alloy of copper and tin. Despite this distinction some types of brasses are called bronzes and vice-versa. Brass i is used for applications where low friction is required. As it is softer than most other metals in general use, brass is often used in situations where it is important that sparks not be struck, as in fittings and tools around explosive gases. It is ususlly relatively resistant to tarnishing.Brass has higher malleability than copper or zinc. The relatively low melting point of brass (900 to 940°C, depending on composition) and its flow characteristics make it a relatively easy material to cast. By varying the proportions of copper and zinc, the properties of the brass can be changed, allowing hard and soft brasses. The density of brass is approximately 8400 to 8730 kilograms per cubic metre (equivalent to 8.4 to 8.73 grams per cubic centimetre).

Today almost 90% of all brass alloys are recycled. Because brass is not ferromagnetic, it can be separated from ferrous scrap by passing the scrap near a powerful magnet. Brass scrap is collected and transported to the foundry where it is melted and recast into billets. Billets are heated and extruded into the desired form and size.

However, brass is susceptible to stress corrosion cracking, especially from ammonia or substances containing or releasing ammonia. The problem is season cracking that is caused by high residual stresses from cold forming of the cases during manufacture, together with chemical attack from traces of ammonia in the atmosphere.