Plug valves are simple devices that start or stop fluid flow and are used for household natural gas lines and many other applications. Be with us to read this article.
What are plug valves?
It is cylindrical/ conically shaped with narrow plugs that can be rotated for controlling flow inside the plug valve body. The plugs present in these valves consist of hollow passageways that go sideways via the plug and this allows the fluid to flow when the plug remains open. It provide direct passage through ports which permits fluid flow with very less turbulence. Fluid flow can be in either one direction completely open or closed. It have a quarter-turn action that easily opens and closes against fluid flow. Usually, It have a body lined with material such as polytetrafluoroethylene (PTFE) and can be used for corrosive services. You will find it of sizes till 18 in (DN 450).
What are some important components of plug valves?
Plug valves are quite different from all other kinds of valves because of the plug disc design and consist of general parts like body, stem, bonnet & disc.
>Body: Every internal component consists of the valve’s body. The valve body links to a pipe via an end connection.
>Stem: The stem connects the actuator to the disc. The stem helps in conveying the actuator’s movement to the plug disc by opening/ closing the disc.
> Disc: The plug disc, mostly known as a tapered disc, acts as a plug. It have a solid metal piece with narrow ends.
> Ports: Plug valve has easy adaption to many port construction. Usually, It is used which offers users advantages: a) Facilitates piping as well as installations b) Provides simple operation as compared to multiple gate valves and eliminates expensive pipe fittings.
What are the benefits of using plug valves?
> Plug valves are one-piece with a simple structure, leak-free and offer hassle-free maintenance in the pipeline. These valves can also withstand strength in the piping system. The valve body has strong permeability and that is the reason why these valves are used in chemical industries which are prey to corrosion.
> The plug is usually veiled by a bushing which makes the plug and valve body with no wear and tear. You can repair and update by just changing the bushing and topmost seal. Mostly these valves meet long-service needs even under high-temperature conditions up to 300 degrees celsius.
> Plug valves have one great benefit of low processing allowance.
> You can easily customize the plug valves following the requirements of users with varied designs (be it into three, four, five, six ports, multi-valve groups etc.)
What are some applications of plug valves?
There are numerous applications of plug valves. Let us have a glance:
> They are used majorly in low pressure and low-temperature services.
> Plug valves are also high capacity valves that can be also used in moderate vacuum systems.
> They are efficient in handling gas & liquid fuel.
> Handles even high-temperature flow like condensate, boiler feed water etc.
> Plug valves are ideal for regulating liquid flow that contains suspended solids (like slurries).
> Bubble-tight services can work well with the plug valves.
> Can be used in air and vapour services, pharmaceutical, natural gas and oil piping, and food processing systems.
Different types of plug valves:
There are different kinds of available in the market and they are mentioned below:
a) Lubricating plug valve – It is use sealants or lubricants that ease their work over a broad range of operating pressure. The lubrication that is used in between the body and plug offers a seal. This seal needs occasional lubricant injection. Users must assure that the lubricant does not get washed away along with the medium because the medium can get contaminated and must withstand line temperature. Use the lubricant which has the following properties – resistance to chemicals, proper elasticity, capacity to form a water-tight seal around the plug’s body which is essential. The sealant offers protection to the metal surface from rusting. It is used majorly in those applications with pressure over 2500 psi.
b) Non-lubricating plug valve – The non-lubricating valves are used mainly in low-pressure lines and consist of an elastomeric body sleeve installed in the cavity. The plug here is tapered and polished. It presses the body liner against the valve’s body and this helps in reducing friction between the body and plug.
c) Eccentric plug valve – The design of the eccentric plug valve uses the half plug and helps in those applications that need high seating force with lesser friction from both opened and closed positions. The chief feature of the eccentric plug valve is – enhanced shut-off capacity. These plug valves are quite efficient in a broad range of isolation and flow controlling services and some other typical known applications are sewage, sludge, clean & dirty water, and other services.
d) Multiport plug valve – These valves are non-lubricating plugs with a three-way flanged design with encapsulated taper plug. which are used to divert applications and are used in the HVAC system, water and wastewater applications.
e) Expanding plug valves – It is quite complicated in design and use multiple components permitting the valve to enlarge mechanically by giving a double block. These kinds of plugs use the rotary mechanism and it offers protection to both seals. The applications that do not need double isolation, these valves are used for avoiding product contamination.
What are some of the plug valve materials?
It is made from various materials while some of the common materials are:
> Steel
>Stainless steel
> Plastic
> Bronze
So, we hope that the article has given a short brief about the plug valves which are quarter-turn valves and extremely useful in frequent and fast operations such as directional flow control, handling liquid and gas fuels, and suspended solids (slurries), etc. Reach out to a reliable supplier to get the top quality valve.
