In an industrial process, valves are used to control flow and pressure in pipelines carrying liquids, gases, fumes, etc.
To this end, we will address here the use of conventional globe valve models and also piston valves.
Conventional Globe Valve
Widely used in industrial processes for fluid flow control and pressure regulation, this type of valve is characterized by its globe-shaped body.
Conventional Globo valves use gaskets as sealing elements. This type of sealing material offers reliability and is recommended for a wide range of industrial applications.
however, the use of gaskets on globe valves, develop recurrent leaks and replacement of this material is necessary. However, this gasket change is hampered by access to it and also by the need to depressurize the entire line, since this maintenance must be done without any pressure on the valve.
This type of valve also uses a gasket between the body and the bonnet. This type of seal may leak and, sometimes, results in erosion of the sealing surfaces, requiring replacement of damaged parts.
Bearing in mind that globe valves also use internal metal type seals / metal, it is possible for leaks to appear, because, considering that this type of fence falls into class IV, dripping is allowed. Besides that, considering that this type of seal does not have the perfect contact, dirt may accumulate on the sealing surface and erosion of these surfaces may occur.
It is important to note that, any loss of vapor must be analyzed and corrected, because it means wasted time, operation and also money.
Loss of vapor through leakage to the atmosphere (kg per hour)
SOURCE: UTILITY LEAK PREVENTION
*THE STEAM JETS ARE MEASURED ONLY IN LENGTH
Considering the table above, that relates the size of the leak jet to the maximum steam flow, if we take as an example a line pressure 9,3 bar, and a jet of steam leak from 90 cm – the vapor loss will be 26,8 approximately kg / h.
Also considering the operating time: 24h / he; 30 days / month – the total steam lost per month will be = 19,3 tons.
Assuming a cost of R $ 60,00 per ton – the total lost will be R $ 1.157,76 a month.
The warning point in the case of the conventional globe valve is that, all these setbacks presented result in a high maintenance cost, waste of inputs and unwanted production stops, considerably harming the cost x benefit of using these valves.
Piston Globe Valves
The Globe Piston valves in turn, present cost x benefit that make the investment feasible.
The piston valve sealing system, occurs through graphite rings that are in contact with the piston. This type of fence, class VI, ensures tightness for both the line and the atmosphere.
The exclusive sealing system of KLINGER piston valves ensures Class VI sealing according to ANSI / FCI70-21 Standards, referring to the passage of fluid to the line.
The efficiency of these graphite rings is given by the insertion of expanded stainless steel sheets and by the special physical properties of the graphite that allow its use in temperatures from -40ºC to 400ºC, being suitable for thermal shocks and vapor changes / condensed.
This seal is based on the contact between the piston (plug) and the inner surface of the seal rings, contact with the lower ring (seat) makes the flow block to the pipe and the contact with the upper ring makes the seal for atmosphere. This contact between the piston and the upper ring replaces the gaskets and the gaskets of the bonnet, that are used in conventional valves.
Piston valves have low cost maintenance, because normally, it is necessary to replace only the sealing rings, items that have a cost of approximately 5% of the cost of the valve. Maintenance is also easier, since the valve can be repaired by keeping the body installed in the pipeline.
Considering the presented characteristics of piston valves, it can be said that this type of valve offers greater reliability against accidents caused by leaks.
Besides that, energy savings and other inputs inherent to the process result in an irrefutable cost x benefit.
In addition to steam and condensate collection systems, the KLINGER piston valve has proven effectiveness in applications such as thermal fluids up to 350 ° C, chemical fluids (stainless steel version) and gases.
This type of valve, also available with special trim for fine adjustment. Yet, this feature is unique to the KLINGER piston valve.