A Complete Guide to Butterfly Valve Problems and Troubleshooting

Home A Complete Guide to Butterfly Valve Problems and Troubleshooting
07/06/2022
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Butterfly valves are used in various industries and can be found on everything from water treatment plants to nuclear power stations. They’re also an important part of everyday life, with many people relying on them to turn off their sinks or shower when they want to conserve water during a drought. But these simple devices don’t last forever; eventually, they will need some maintenance and repair work done on them. 

Butterfly Valve

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If a valve malfunctions, it can cause major damage to other equipment down the line or, even worse, result in an explosion that could destroy your entire facility.  Make sure to buy one from a reputed industrial valve manufacturer.

Do you know your way around a butterfly valve? If not, don’t worry. This comprehensive guide will teach you everything you need to know about butterfly valves so that you can troubleshoot problems and get them fixed quickly!

How Does a Butterfly Valve Work?

A butterfly valve is quite similar to a quarter-turn valve. The valve will shut or open at any time you turn the handle 90 degrees (a quarter of one turn). The principal function of these valves is to regulate fluid flow across a pipe area. Butterfly valves are commonly employed in waste treatment systems.

Concentric butterfly valves work the same way as quarter-turn valves. Understanding how a butterfly valve functions is quite easy. It will allow you to understand the various components of valves.

Butterfly valves consist of a variety of components. The most important is the disc made of metal. The metal disc is often known as the butterfly. The butterfly is attached to rods and, if the valve gets shut, it stops the flow of fluid. A quarter-turn moves the butterfly or disc made of metal once the valve opens. The passageway is free of obstruction, allowing air, fluids, or other fluids to move through.

Butterfly Valves

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The motion of the disc is contingent depending on whether the valve opened or closed or if it is closed fully or partially. When the valve has been closed only a portion of the time, it will not be rotated for a full quarter turn, and therefore does not provide unrestricted flow. 

This means that lesser amounts of air or liquid will pass through. If the valve is completely opened, the disc will be turned 90 degrees, and greater quantities of fluid or air will pass through. 

A variety of other parts make up this butterfly valve. It includes the resilient seat body, packing stem, and actuator. The resilient seat is mounted onto the body of the butterfly valve to ensure a proper seal. The packing offers an additional seal, particularly when the resilient seat is damaged.

Butterfly valves are designed differently. They can be operated manually, while others use electronic technology based on the specific system. They are also available in various types. They offer superior performance in large pump pipes and front-suctions.

Install butterfly valves

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Butterfly valves are also utilized in automotive systems. For instance, you can discover the butterfly valve within the carburetor in a car. In this scenario, the valve serves to regulate the airflow through the car’s engine. It can open partially or close to control the air flowing through.

Where are Butterfly Valves Used?

Butterfly valves or gate valves are suitable for pipelines with large capacities that transmit non-corrosive and corrosive fluids in various applications, such as furnaces, pipelines, petroleum processing pipe liquefied with petroleum gas hot and cold chemical smelting and energy production, protection of the environment, water treatment, construction, and many other engineering systems. It’s used to regulate and shut off fluid flow.

How to Test Your Butterfly Valve?

Check valves can be described as pressure vessels that have to withstand moderate pressures without leakage. The valve body, the valve cover, and other crucial components should be free of fractures, lost Slag pores, and other imperfections that can affect durability.

Many valve tests can be carried out throughout the process of production. It is essential to conduct tests on valves throughout the entire process, from design to manufacturing and installation, through operation and maintenance. 

However, the most significant valve tests are performed before the factory removes the valve. Quality assurance specialists conduct numerous close-up inspections and test specific to the valve to identify imperfections and adjust accordingly. After the tests are approved, the product can be utilized. 

What is the Correct Pressure Test Method?

Pneumatic butterfly valves or  dual plate check valves are subject to the same requirements for strength tests as shut-off valves. The test medium must be injected from the inflow end to evaluate the valve’s sealing capabilities. Check that the butterfly plate has been closed, the other side shut, and then inject the test medium at the appropriate pressure specified in your test specifications.

Closing the butterfly plate following verification that there’s no leakage around the sealing of the stuffing and other components. Unlock the other end, and if there’s no leakage in the butterfly plate’s seal and it’s qualified, then it’s considered to be. The butterfly valve used to regulate flow control may skip the sealing performance test.

Common Butterfly Valve Failure and how to fix

The most common failure of a high performance butterfly valve is the rubber elastomer inside the butterfly valve. It can tear, wear, wear or perforate and even fall off after continuous use. The conventional thermal vulcanization procedure is not able to meet the repairs on-site. 

Special equipment is utilized to repair and requires a significant amount of heat and electricity, requiring time and effort. Nowadays, we employ an innovative method of gradually using polymer composite materials to replace the traditional techniques. 

The outstanding adhesion and superior durability against the wear and tear of their products guarantee that the repair cycle can meet or even exceed the original parts’ lifetime and significantly reduce the time spent in repair.

  • Before installing, verify that the performance of the products manufactured by our factory and the direction of flow of the medium is following the conditions under which it operates, and then place the valve in the cavity to cleanse it. No foreign materials attached to the sealing ring or butterfly plate are permitted. The butterfly plate is permitted to be shut to keep the sealing ring from being damaged.
  • It is suggested to use the specific flange for disc valves, The HGJ54-91 socket weld steel flange.
  • The installation’s position in the pipeline. The ideal position is vertical; however, it cannot be reversed.
  • This flow has to be adjusted in the course of usage A the worm gearbox is utilized to control the flow rate.
  • For the valve on the disc that has longer closing and opening times, remove the cover for the worm gearbox after approximately two months. Check whether or not the amount of butter remains in good condition and ensure that you have a sufficient quantity of butter.
  • Verify the connection components to be secure to guarantee the filler’s bee and ensure that the filler can freely rotate the stem of the valve.

Butterfly Valve Assembly and Installation Guide

Assembly of Butterfly Valve

  • Clean all components of the lug type butterfly valve. Apply the silicone-based base oil or any other lubricant to assist in assembly.
  • Install the bearing bush inside the body of the valve.
  • Install your seat in the valve body. Be sure to ensure that the holes are aligned in the body and seat for easy pipe movement.
  • Disk inside the valve seat by putting taper pin holes pointing towards the top of the valve plate and placing stem holes in the right direction.
  • O-ring for installing packing.
  • Install the packing gland and attach it with screws.
  • Install the bottom cover.
  • Find the taper pin holes on the disc with the holes on the stem and insert taper pins. Tighten them securely.

Instructions for installation and the steps to open a butterfly valve

Before installation of wafer butterfly valve:

  • Before installation and operation, clean the pipe with air and then wash the pipe’s inner surface using water.
  • Check that the condition of service for the valve is compatible with the performance specifications of the valve; (temperature and pressure)
  • Find out if there are any impurities in the valve channel or the sealing surfaces, then remove them as soon as possible;
  • After unpacking, the valve must be installed at the appropriate time. Don’t loosen the nuts or screws on the valve;
  • The fitting in a butterfly valve is required for the wafer butterfly valve.
  • Butterfly valves with electric motors can be installed at any angle to the pipeline. It is not recommended to position them upside-down to ease maintenance.
  • When installing the butterfly valve, flanges are necessary to ensure that the flange’s surface and the seal rubber are in alignment and that the screws are tightened evenly. 
  • The surface of sealing should be perfectly seated. If the force applied to tighten the screws isn’t uniform, it will cause the rubber to bulge and stop the butterfly plate as well as the valve rod may leak because of the adhesion to the plate.

Steps to install wafer Butterfly valve

The proper installation of the butterfly valve will determine the seal quality of the butterfly valve and whether it is leak-proof or not, and the safety when operating in working conditions. The user must be aware of the process of installation.

1. Position the valve between two flanges that have been pre-installed. Pay attention to the location of the bolt holes.

2. Install four bolts, nuts, and bolts into the hole in the flange and then make sure the nuts are tightened slightly to improve the smoothness of the surface of the flange;

3. Spot welding is used to secure the flange to the pipe.

4. Take the valve off;

5. The flange should be completely connected and fixed to the pipe

6. Install the valve once the weld joint has been cooling. Check that the valve is fitted with enough space to move in the flange to protect the valve from becoming damaged. Also, ensure it is fitted with a valve that is of an appropriate opening;

7. Make sure the valve is in the correct position. Valve and ensure that the four bolts.

8. The valve should be opened to ensure your valve can be opened and closed freely. Then, slightly let the valve plate open;

9. All nuts should be tightened evenly;

10. Check that the valve opens and closes without difficulty.

The clip-on butterfly valve is to be placed horizontally before installation and should not be pushed around in any way. Once it has been extended to the installation length in the installation process, it’s not permitted to remove the butterfly valve that is clip-type without permission from the design of the field pipeline. 

This is something we have to be aware of before installation. We must also be aware that the double-clip butterfly valve can be used in any location. However, once you have installed the clip-on butterfly valve, the butterfly valve has to be laid on the line. 

After the bracket has been constructed, it is not allowed to remove it while using it.

Butterfly Valve Seat Replacement Guide

A valve’s seat forms the area that vents floating ball valves for intake and exhaust rest when the valves are shut. This seat is an essential element in combustion, and when the valve isn’t sitting properly, it may let combustion gasses leak and reduce compression. 

In addition to this crucial process, the valve seat is used to transfer heat from the valves to the head of the cylinder.

In time the valve seat may get worn down, reducing its efficiency and causing an increase in compression. If we cannot cut the seat because of the severity of wear, we can take it off the seat and install an entirely new valve seat. 

We make these valve seats according to by using blanks. If the valve’s seat has been installed into the head of the cylinder, we can make it into IDL. IDL and then fabricate seats that fit.

The replacement of seats in valves is essential to convert engines to run fuel that is not led. Suppose you are converting when you are doing a conversion. 

In that case, you must change the exhaust seats to an extra durable material because of the increased temperature that occurs in combustion.

We can purchase the valve seat in various sizes that we can adapt to fit virtually every bike. We use the most sophisticated technology, SERDI, to slice valve seats and make old seats machined out. We have standard steel OEM seats and Beryllium Copper seat valves to suit top-quality cylinder head applications.

What to Consider When Choosing Butterfly Valves?

If you are considering butterfly valves for your business, it is necessary to know a few things before deciding on the specifics of the technology of your valve. 

The most important information you need to know is the purpose of the angle globe valve, the type of fluid, the method of operation, and the installation method, which will be explained below.

Type of Fluid

The next step is to identify the kind of liquid or substance circulated through the system. Butterfly valves generally can handle gasses and liquids; however, they cannot accommodate bulk solids. Find out the characteristics of the media. It may be corrosive, which means it requires the valve body to be made of stainless steel as well as the disc. But, you can utilize carbon steel or less expensive alloys for common fluids such as water.

Mode of Operation

Once you know the kind of fluid, you will select the operation mode that the valve will operate. Manufacturers and suppliers typically have various options in this regard. 

The choice will be based on the area of the valve, its application, price, and the frequency at which you must switch off and on the valve.

Mode of Installation

Then, be aware of whether you need to flange the valve on both ends or if you need to weld it or screw it between two pipes.

Once you have gathered this information, you will be able to identify the technical specifications for the butterfly valve you are installing as aligned with the manufacturer or the supplier.

Capacity

The capacity is the flow rate or the rate the material can pass through. This also includes the safety of the internal pressure capability for the valve. Be sure to verify the specifications for the butterfly valve to ensure you purchase the right valve for your system requirements.

Level of Precision

Every valve manufactured by a company has specifications that define the leakage quantity or volume. It also specifies the shut-off specifications, the passageway’s length, and the amount of fluid it can hold when fully open.

Operating Life

Typically, you will find the operational life of the valve in its specifications sheet. In general, butterfly valves offer lower maintenance requirements and still provide a tight, bubble-free shut-off.

Pressure Drop

Pressure drop is an essential aspect to consider when selecting the appropriate valve to suit your particular needs. It defines the variation in pressure between the outlet and the inlet of the butterfly valve.

It is recommended that “If the pressure drop across the valve completely opened isn’t sufficient to make up for the drop occurring in the valve, this could cause a minor change concerning the movement of fluid up to the valve is shut. In this scenario, the fast-acting valve will be the best choice. .”

How to avoid problems With Butterfly Valves?

The majority of issues caused by butterfly valves or swing check valves are because of inadequate installation, and not  because of the valve itself. For this reason, it must be noted that butterfly valves must be installed correctly during the commissioning process to decrease maintenance issues.

One thing to be examined while installing is that the seal must be made of elastomer. It is prone to move toward the surface of the valve and then gets compressed as you install it. Therefore, its effects will quickly disappear, and the valve will not fulfill its function to seal the valve in operation. So, care should be taken when installing the valve, not to hide sealing material.

Another situation is when discs extend beyond the body’s surface and close to the valve. It is important to check to see if the disc can rotate freely when entering the valves. 

The Bottom Line

There you go. We’ve concluded this article. We hope that this guide gave you an understanding of a butterfly valve, its function maintenance, as well as installation. Most importantly, we hope that it gives you an idea of how to choose and buy butterfly valves from manufacturers/suppliers.  For more such information, you can contact us.

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