Ever since mankind discovered the process of boiling water to create steam, the need for a safety device became quite essential. The increase in the number of boiler explosions early in the 19th century has led to the first discovery of safety valve. The main function of these relief valves is to protect life and property. Most of these valves are used to prevent the development of over pressure in steam boilers, plants and pressure vessels.
Safety Valve-Main Functions
Every plant, steam boiler and pressure vessels require safety devices to release the extra pressure or the pressure that has reached the predetermined level. These valves operate in a safe manner to release the fluid and thereby reduce the extra pressure. It is important to install safety valve in all kinds of pressure containing vessels where the maximum pressure is likely to exceed the permitted limit.
These relief valves are also used to prevent potential damages to the products due to excessive pressure. There are many reasons for the build-up of excess pressure such as exposure to plant fires, temperature changes, and imbalance in the flow of fluids. Different types of valves are used for different applications. Today it is also easy to find a number of designs that meet the requisites of various national standards of safety. Most of these valves have the feature of immediate opening or pop-up action. The term safety valve is correlated to PSV or Pressure Safety Valve and PRV or Pressure Relief Valve in various industries such as pharmaceuticals, petrochemical industries, power generation, food industry and so forth.
Selection of Safety Valve
With such a large variety of valves, it is quite simple to choose the appropriate valve that meets the precise requirements of any product. While selecting valves it is quite essential to consider the size and pressure of the product so that the most appropriate valve can be selected without any difficulty.
There are however many factors which determine the selection of safety valve and some of the most important among them are as follows.
Price of the valve: One of the most significant factors that needs to be considered while choosing valves include the price of these valves. Today there are many manufacturers and dealers who supply a variety of valves that suit different applications. However, it is quite imperative to consider the nominal size and the capacity of these valves before comparing the relative prices of the valves.
Variety of disposal system: There are various types of disposal systems involved in the functioning of these valves. Closed bonnet system should be used in liquid or gas applications as it is quite unsafe to release these substances into the air. The open bonnet system is used for non-toxic gases and steam which can be released into the atmosphere.
Construction of the valve: Another specific factor to be considered includes the construction of the valve which should be considered before choosing a safety valve.
The other important factors to consider before purchasing these valves include the standard code and the performance level of these valves.