Butterfly valves are intended to control or separate a system’s flow. If there is no liquid flowing through the pipeline, the valve is used to repair, clean, or modify liquids because it has the power to begin, halt, or prohibit flow in a pipeline system.
The butterfly valves can be used for a huge range of applications, including water supply, wastewater treatment, slurry services, fuel handling systems, vacuum service, fire protection, power generation, compressed air and gas application, chemical and oil industries, ships, refineries, and so on.
Due to the wide range of butterfly valve applications, proper installation of the valve is vital so that they would work without any problem. In case of improper butterfly valve installation, many issues will arise, such as leaks, problems with flow, etc.
The butterfly valve manufacturer produces a wide variety of butterfly valves in different models, and choosing the right design that fits the desired applications is essential. To help people know the appropriate way to complete the butterfly valve assembly and install butterfly valves, this guide is created.
Fundamental Information About Butterfly Valves
A butterfly valve is a device that controls material flow across high pipe widths by quarter-turning the disc. An actuator that regulates the motion of the disc is coupled to a rod that grazes through the disc’s center. The disc can be parallel or vertical to the medium flow.
Since the butterfly valve disc is constantly in the flow, it results in the change of pressure. A quarter-turn valve is what the butterfly valve is categorized as. It has the potential to open and shut down gradually and can also quickly shut off like a ball valve. Due to this distinction, the disc is constantly a part of the flow and permits a reduction in pressure.
The pipe’s core is where this disc is affixed. A rod that is put into the disc and an actuator that is situated on the valve’s outside work together to control disc movement. The actuator’s rotation places the disc either parallel or vertical to the flow. High-performance butterfly valve designs improve the interference between the seat and the disc edge by using the pipeline pressure.
The valve can essentially be opened and closed manually using a handle and gear or automatically using electric, hydraulic, or pneumatic actuators. These tools enable the disc to be strictly rotated to positions varying from completely opened to shut down. Manual actuation is regarded as a practical and affordable technique, and it is simple to use as well.
A dependable technique for remotely operating valves is automatic actuation. These actuators allow for the quick functioning of bigger valves. Actuators can be made to fail-open (remain open in the event of an actuator failure) and fail-close (remain closed in the event of an actuator collapse). In addition, they frequently also include a manual actuation mode.
Butterfly Valve Types
Based on the piping connection design, there are three different butterfly valve types, which are: wafer type butterfly valve, lug type butterfly valve, double flange butterfly valve, and butt-welded butterfly valves. The primary difference between lug type butterfly valve installation and wafer type butterfly valve installation is the way of attaching the bolts between the valve and flanges since the flanges’ location differs in each valve type.
When it comes to the disc closure design, there are two types of butterfly valves which are concentric butterfly valves and eccentric butterfly valves (single-offset butterfly valves, double-offset butterfly valves, and triple-offset butterfly valves).
Depending on the operation procedure of the valve, there are manual actuation butterfly valves (lever-operated butterfly valves and gear-operated butterfly valves) and automatic actuation butterfly valves (electric butterfly valves, pneumatic butterfly valves, and hydraulic butterfly valves).
Taking into account the different seat materials, there are two different butterfly valves, which are soft seated butterfly valves and metal seated butterfly valves.
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.
- Disc Clearance
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.
- Opening Rotation
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 valves 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.
- Necessary Bolting
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.
What To Know About Unpacking and Storage Of Butterfly Valves
In order to make sure that the butterfly valves are not damaged before installation in the desired applications, it is vital to be familiar with the unpacking and storage precautions of these valves.
Butterfly Valves Unpacking Instructions:
- To ensure that the size, substance, and trim are accurate, compare the ordered packing list to the valve that was received.
- Verify that neither the valve nor the operator was harmed during shipping.
- Make sure not to open the valves until they are prepared for installation in order to safeguard the seat and seals. This way, it is possible to shield the valve from dirt and debris, which could potentially result in seat leaking.
Butterfly Valves Storage Instructions:
- Be careful not to harm the operator, disc sealing edge, or flange faces when raising the concentric butterfly valve.
- If the valve needs to be kept somewhere before being installed, it needs to be shielded from the severe environmental elements.
- To protect the sealing edge and the seat, put the valve and the disc in a nearly closed position.
- Keep the valve clean and clear of trash, debris, and corrosive substances.
- Store the valves on appropriate skids or pallets, shielded at the flanges, and in a dry environment.
- If storing for a longer period of time, save in a cool, well-ventilated area. Make sure it is protected from the sun as well.
Butterfly Valve Pre-Installation Instructions
Make sure that the temperature and pressure situations are within the range required for the product to be installed. Check if the butterfly valve’s construction materials are chemically compatible with the media running through the pipeline. Verify that the pipeline’s flanges and the valve’s flange ends are neat and defect-free.
The pipeline’s alignment needs to be examined as well. It is never recommended to realign an existing pipe system using API butterfly valves. To guarantee there is enough clearance for the installation of the valve, the distance between the pipe flanges must be measured. Bigger valves must be able to be lifted into place using the proper material handling tools.
These valves are bi-directional, and the butterfly valve installation direction flow can be either vertical or horizontal. If there is a choice in stem position, the valve has to be installed with the stem in the flat position. By evenly distributing the weight of the stem and disc, this will lessen seat wear. Additionally, the horizontal stem position produces a self-flushing action if the medium is abrasive, which will increase the service lifespan of the valve.
Verify that there are no interferences and that the current pipe sizes correspond to the inlet and output sizes of the installation unit. Additional support can be required if pipeline strain is an issue with larger valves. There is no need for extra gaskets because the rubber seat serves as the seal between the flanges as well.
If at all possible, it is advised to install certified butterfly valves with at least six pipe diameters from upstream parts and four pipe diameters from downstream components.
General Installation Cautions
Here are the basic butterfly valve installation cautions that need to be followed during the valve installation procedure.
- These valves cannot be fitted with Class 250 cast iron or Class 300 steel flanges.
- Mechanical or rubber-facing flanges should not be used.
- Steam service is not advised for BV/BV-D valves.
- These valves must not be used in regions where it is impossible or hard to inspect them.
- When welding flanges into the line system, valves should not be attached to them in order to prevent heat damage to the seat.
- Up to 12″ lever-style butterfly valves are available, although based on the flow rate and other variables, valves 8″ and bigger could need a gear operator to properly close.
- Prior to conducting a loop test of the piping system using line pressure from tested valves, make sure that all valves are totally open.
- Make sure to fully release the line pressure before removing valves from pipes for maintenance or any other reason. Under the line pressure, slacking piping nuts is risky and may harm the valve. The pipeline must be entirely drained of any remaining liquid.
Step-by-step Butterfly Valve Installation Guide
Have a look at the step-by-step butterfly valve installation guidelines for installing this valve in the correct way quickly and effectively.
Install the hand-wheel for the gear-operated valve or the lever if the valve is manually operated. Make sure the valve is completely closed by turning the lever or hand-wheel in the clockwise face. The disc needs to be parallel to the edges.
For lever style, if the disc is not parallel to the ends, slacken the top plate a little by removing two bolts, move the lever counterclockwise until the disc is in the center and parallel to the ends, and then fasten the top plate. Revise the hex nuts on the gearbox’s side for gear-operated valves. To ensure proper functioning, open and close the disc completely many times. Repeat this procedure if re-alignment is vital.
Install the valve into the piping system now. It is vital to keep in mind that tapped lug style butterfly valves are put in between the flanges with tiny cap screws on the valve’s inlet and outlet. However, the wafer style valves are positioned in between the flanges and fastened with completely threaded studs.
To avoid grimace or any harm to the seat’s sealing face, it is better to disperse the flanges such that they are 3/16″ larger than the valve’s face-to-face size. Make sure that any foreign material like scale, dirt, welding slag, or metal shavings is completely removed from the pipe flange faces.
Close the disc and cautiously place it in between the flanges, align it, and center it. Keep in mind that precise centering between the upstream and downstream pipe ends is necessary for the valves to work without any issues. Secure the hand-tightening flange bolts while slowly withdrawing the flange spreader and making sure that the valve is centered on the flanges.
To ensure that the disc can travel freely without obstruction and that there is no connection with the piping or flanges, progressively open the valve to the entirely open position. The installation of valves in pipelines with smaller-than-normal interior diameters, like plastic-lined pipe, heavy wall pipe, decreasing flanges, or as-cast flanges, may cause disc interference.
Attaching directly to a swing check or quiet check might also cause interference. To peel off these blockages, appropriate corrective actions have to be accepted, like taper drilling the tube or adding a spacer or spool piece.
Flange bolts must then be fastened to the specified torque values once proper functioning has been confirmed. To pack the bolts evenly, it is best to utilize a star or criss-cross design.
Pump up the piping leading to the valve and check for leaks. When fastening bolts securely, utilize a cross-over pattern and gradually boost torque if leakage is seen. The installer has to confirm the appropriate bolts’ strength for the application. Bolts need to be free of lubricant, neat, and clean.
Assembly And Disassembly Of Butterfly Valves
Knowing how to assemble and disassemble the butterfly valves is vital, and the detailed steps are listed in this section.
Guide To Butterfly Valve Assembly
Check out the following step-by-step instructions for assembling butterfly valves:
- Clean each component completely. Check the components for any flaws.
- The interior surfaces of the body, even the upper and lower shaft openings, should be greased with silicone grease solution.
- Shaft bushings should be placed into the body with caution so that they will not obstruct the body seat bore.
- Ensure the shaft holes in the seat align with the holes in the body before installing them in the middle of the body.
- Apply silicone oil liberally to the seat’s interior surfaces. Thrust the disc slowly into the seat when it is wide open (90 degrees to the body.) As near as possible, align the disc’s shaft holes with the seat body’s shaft holes.
- Utilize a twisting motion to align the keyway in a similar way with the disc after putting in the shaft through the body and disc.
- Taper pins should be injected into the disc, then fixed with two or three hard blows. Put the dust protection above the shaft and on the top of the body after applying silicone grease on the dust shield.
- The screws should be inserted through the valve’s body and into the seat if it has a dead-end service design.
Guide To Butterfly Valve Disassembly
Here are the brief steps to disassemble the butterfly valves when necessary.
- Place the valve in the flat position with the disc closed.
- With the help of a hammer and punch, unfasten the taper pins from the valve disc. To prevent the taper pin from deteriorating, the punch must retain a diameter that is equal to or bigger than the tiny edge of the taper pin.
- Peel off the taper pin from the disc. Make sure to take out the valve shaft from the body with the help of a twisting motion.
- Ensure to avoid damaging the seat or disc sealing edge, and peel off the valve disc from the body.
- The cartridge seat can be withdrawn from any side by pushing it through the body while uniformly applying pressure in one direction. Pull out set screws around the body’s perimeter that prolong into the seat if the valve is of the dead-end service design before withdrawing the seat.
- Shaft bushings should be taken out of the body as needed.
Operation And Maintenance And Field Testing Of Butterfly Valves
To ensure proper use of butterfly valves after installation, it is vital to know about their operation, maintenance requirements, and field testing of these valves.
Operation Of Butterfly Valves
Use of the valve over its working pressure is not recommended. Inspect the actuator action if the valve is stuck somewhere between the open and closed positions. To identify the issue, it is also a wise idea to peel off the actuator and manually run the valve. If required, withdraw the valves and inspect them for foreign items. Unreasonable torque from the actuator can cause harm to the interior valve components.
Maintenance Of Butterfly Valves
If the valve is not utilized repeatedly, it is best to cycle it one time every month or more (depending on the usage). Before keeping the valve open, release the system’s pressure. Switch the installation order to peel off a pipe. By withdrawing the stem and disc, it is possible to substitute the valve seat. Replace the liner with a fresh component after pressing it out.
Along with the seals and clips, attach the disc and stem back to their place. Refit the line according to the installation order. To extend the lifespan of a valve functioning in a dry environment, make sure to lubricate the disc and seat from time to time.
Field Testing Of Butterfly Valves
Here are some things that one needs to know about the field testing of the butterfly valves.
- Only the rated pressures are intended to be held by rubber-seated butterfly valves. The valve may be harmed by test pressures that are higher than the recommended working pressure while it is closed.
- The pipe system can be inspected up to the valve hydrostatic test pressure with the disc in the open status.
- When there is a foreign matter between the seat and the disc, seat leakage can happen. Unlock the valve 10 to 15 degrees if it happens to get a high-velocity flushing movement. Lastly, repeat this process if required.
- A rotational shift in the disc’s position in reference to the body may cause seat leaking. If necessary, modify the actuator or close the gearbox’s stop.
- Actuator stops can be set for dry applications to prevent the disc from completely burrowing into the seat. Although the seat’s lifespan will be extended, a bubble-tight seal will still be possible.
What Are The Benefits Of Installing Butterfly Valves
Because of the broad advantages of butterfly valves, they are often used in a variety of applications in different industries. Check out their primary benefits:
- They open quickly and easily.
These valves can be totally shut down or opened with the 90-degree handle rotation. Big butterfly valves typically have a gearbox where the hand-wheel is attached to the stem via gears. As a result, the valve’s functioning is made simpler.
- Less space is needed for them.
Butterfly valves offer a significantly reduced installation footprint thanks to their compact shape and tiny face-to-face size. They provide help in reducing installation expenses, such as labor, tools, and pipe support.
- They are very inexpensive to make.
Because of how they are made, butterfly valves use less material. The wafer type that matches between two pipeline flanges is the most affordable option. Bolts that connect the two flanges and depart through gaps in the external casing of the valve have a lug wafer design. In addition, the commonly used butterfly valve materials are frequently less pricey.
- They require little to no upkeep.
Butterfly valves are widely used because of their dependability and minimal maintenance needs. The valve’s lifespan can be extended due to its lower wear level. It lowers the hourly cost of valve maintenance and lessens the direct operating expenses.
- They have a versatile installation.
Butterfly valves come with a broad variety of installation cases, and it is possible to use them underground and above ground as well.
Where Butterfly Valves Are Often Installed
Butterfly valves’ 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 valves 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 valves fulfill these traits, so they are often installed in piping applications.
The butterfly valves 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 valves 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.
The development of the butterfly valve has made it possible to enhance procedures and applications across numerous sectors. The butterfly valve can endure severe temperature conditions. In high-stakes applications like energy output and petroleum processing, the seal’s integrity must be maintained at all times.
They function very well in applications involving high volumes of water and sludge. If your business necessities a bulk installation of butterfly valves in different applications, get in touch with a reliable industrial valve manufacturer to get affordable quotes for bulk butterfly valve orders.