Views: 24 Author: Site Editor Publish Time: 2023-02-18 Origin: Site
In short, a butterfly valve is a quarter turn rotational motion valve. Just like any other valve, they are used to either start, stop, and regulate flow. This type of valve has been around since the early 1930s and has a wide range of applications in industrial set up. Butterfly valves are made from various materials and their name comes from the functionality of its discs, even though the more accurate name would have been Disc Valve.
The working principle involves rotating their lever 0- 90°— this provides either a complete opening or closure of the valve. Another important feature is that these valves can be equipped with a gearbox-like mechanism. In the setup, the hand wheel from the gears is connected to the stem, making the valve easy to operate but at low speeds and for larger valves. With that in mind, let’s look at ways to install different types of butterfly valve.
Prerequisite Knowledge Before Initiating butterfly valve Installation
Prior to installing the butterfly valves, it is beneficial to understand the following aspects related to these valves.
Ratings Of The Valve
The nameplate that is fastened to every butterfly valve specifies the pressure at which the valve is meant to be utilized. Prior to beginning the installation, verify the valve’s working temperature and pressure rating.
Valve Seat Location
Since the butterfly valves are entirely bi-directional, seat orientation is not necessary for installation. Installing with backflow prevention into the valve’s seat side is required for specific valve models. When the valve is oriented in this way, 25 to 150 psi across the valves will result in a bubble-tight cutoff.
Ensure that the ID of the tube and the flanges are big enough to permit the disc rim to slide into the opening freely before installing the valve. The performance of the valve might be significantly impacted by the deterioration of the disc edge.
Without endangering the valve or elastomer seat, the butterfly valve disc can revolve 360 degrees. The shaft can be rotated in either a clockwise or counterclockwise direction to open the valve.
Valve Location And Installation Position
The valve disc must be barely open but can not expand past the valve liner face in order to minimize damage to the disc and seat during installation. By placing the disc in the nearly closed position when installing the valve, seat interference and torque buildup will be lessened. Installing the durable butterfly valves with the shaft horizontally is preferred in most cases.
The weights of the shaft and disc are uniformly distributed in this situation, reducing seat wear. Butterfly valves are often made to function between two flanges. A lug-style valve with the dead-end service function must be utilized if the valve installation only needs one pipe flange.
If at all possible, butterfly valve have to be positioned at least six pipe diameters away from other line components. Though this is not always practical, it is still necessary to maintain the distance as far as possible. Make sure to leave a sufficient area between the butterfly valve and the check valve or tube where it is attached to make sure that the disc does not interfere with the nearby equipment.
Valve and Flange Preparation
Future issues can be prevented by properly preparing the valve and tube for installation. There should be no debris, dirt, grit, dents, or surface imperfections on any valve seat or pipe flange as they could interfere with flange sealing and result in outer leaks. Additionally, the sealing surface of the valve disc must be examined to remove any debris or foreign substances that could impair the valve’s functionality.
Tools For Installation
The only equipment needed to put in a butterfly valve is a wrench that can be used to tighten the flange bolts and screws that hold the valve in place. For assistance in manipulating valves 10″ and bigger, a hoist could be needed. Typically, smaller valves can be installed with ease in a short period of time. To help in valve installation, temporary line supports can be utilized to maintain the parallel alignment of flange faces.
It is critical to understand the size, kind, and quantity of bolts required for butterfly valve installation. Ensure that you are aware of the best guidelines depending on pipe flanges that adhere to ASME 125/150 regulations.
Here is the installation process:
Clean the pipeline of all contaminants.
Determine the direction of the fluid, torque as flow into the disc may generate higher torque than flow into the shaft side of the disc Position disk in the closed position during installation to prevent damage of disc sealing edge If possible, at all times the valve should be mounted with the stem in horizontal to avoid pipeline debris collecting at the bottom and for higher temperature installations It should always be installed concentrically between flanges as mentioned above. This helps to avoid damage on the disc and eliminates interference with the pipeline and flange Use an extension between the butterfly valve and wafer check valve Try the disc by moving it from the closed position to open and back to ensure it moves flexibly Tighten the flange bolts (tightening in sequence) to secure the valve following the manufacturers recommended torques THESE VALVES REQUIRE FLANGE GASKETS ON BOTH SIDES OF THE VALVE FACE, SELECTED FOR THE SERVICE INTENDED
Where Butterfly Valves Are Often Installed
butterfly valve’ primary uses are in the chemical, pharmaceutical, and food industries, as well as in the regulation of water flow in dams and hydroelectric power generating factories. These valves are either utilized with a control function or a protection feature in the latter applications. The trendy butterfly valves are also used to regulate the water input at the underside of opening lines.
Due to their on-off effects on the fluid flow, butterfly valve are utilized as a safety precaution to permit maintenance to other areas of the dam or supply plant site. More particularly, these valves are often manipulated as safety for turbine applications, penstock, and fluid discharge.
In order to control fluid flow in a system pipe, properties like straightforward design, enhanced durability, and low maintenance are required. The butterfly valve fulfill these traits, so they are often installed in piping applications.
The butterfly valve are frequently seen in refineries as well. These applications would normally utilize a triple offset model and bubble tight or a high-end and high-performance valve with steel bodies. The resiliently seated variant is used in numerous water-related applications.
butterfly valve are frequently utilized in ships where ABS-approved substances are chosen due to their great resilience in seawater. In order to stop any flow, this kind of valve efficiently produces a water-tight shutdown in the ship’s piping system. They can be employed in compact places on ships, thanks to their tiny size. They have numerous applications, including shipside, ballast systems, jack-up rigs, and more.