Pros and cons of ball valves

The ball valve was invented in the 1950s and is today widely used across many industries including the chemical, petroleum and paper making sectors as well as in water treatment plants. The virtues of this simple device are numerous but there are also some limitations associated with ball valves. The ball valve consists of a ball with a hole in the middle which sits inside a passageway. Both fluid and air can pass through the hole. When the ball is turned so that its hole is inline with the pipe, fluid or air passes through. When the hole does not line up with the pipe, the movement of fluid and air cease. This simple design allows plastic bodied ball valves to withstand temperatures of up to 100ºC and pressures up to 16 bar making them ideal for most industrial applications. The sturdy and simple design of the ball valve means that it can usually maintain and regulate high pressure, volume and a high flow effectively. The device also generally has a long-service life. Ball valves are also easy to use and repair. The uncomplicated design allows for quick and easy access to repair seats and seal. Available in a range of sizes, predominantly from a ½ inch to 4 inches, users will find abundant choice. They also come in different body styles including both 2 and 3 way configurations. Perhaps the biggest down side with the ball valve is that if you dramatically increase or decrease the flow rate through the pipe system, a linear flow with ball opening cannot be achieved unless the ball is replaced with a linear flow...

Electrofusion failures in the field

Controversial as it may be, the reality is, that many of the electrofusion failures in the field are often due to the implementation of incorrect procedures by untrained and/or uncertified workers, or simply by qualified individuals seeking to cut corners for one reason or another. More than 70 per cent of the electrofusion failures, which we see in the field, are due to poor installation procedures. If the electrofusion process has not been correctly adhered to, then there is a high probability that the joint may fail and impact on the effectiveness of the pipe system. If done correctly, electrofusion is a practical and safe joining method for building Polyethylene (PE) pipe systems to supply and convey fluids and gases under pressure. It’s also ideal for the maintenance of active gas and water pipelines. Electrofusion, which is the method of joining two elements (pipes and/or spigot ended PE fittings) by melting the outer surface of the pipes and spigot ended fittings together with the inner surface of the E/F fitting using its built-in electric wire, is affected by three critical factors – pressure, temperature and time. These three critical factors are instrumental to the success of the electrofusion process. Time is required to complete the task correctly, while attaining the desired temperature and contact pressure between the surfaces to be joined is vital. If electrofusion is undertaken by not using the right equipment, cleaning methods, process and required time, then the three critical factors are compromised and the success of the joint may be questionable. If you are tasked with having to implement or oversee an electrofusion joint, please...