Views: 181 Author: Site Editor Publish Time: 2023-01-13 Origin: Site
Butterfly valves are employed in a variety of sectors, from nuclear power plants to water treatment facilities. They are a crucial component of daily life for many people, who depend on them to switch off their sinks or showers in order to save water during a drought. However, these straightforward technologies ultimately wear down and require maintenance and repairs.
If a valve breaks down, it might seriously harm subsequent machinery or, worse still, trigger an explosion that could completely destroy your facility. Make sure you choose one from a reputable manufacturer of industrial valves. You will learn all there is to know about butterfly valves from this thorough manual, enabling you to rapidly diagnose and resolve issues.
How To Test Your Butterfly Valve?
Butterfly valves may be thought of as pressure vessels that must maintain tight seals while withstanding modest pressures. Fractures, missing Slag pores, and other flaws that might reduce durability shouldn’t exist in the valve body, valve cover, or other important parts.
Valve Shell Examination
Leaks are detected by partially opening the valve and subjecting it to hydrostatic pressure 50 percent higher than the rated working pressure. During this test, a specific amount of pressure is delivered. There are also water temperature restrictions (41°F to 122°F).
To pass the test, there must be no leakage from the valve. When using stainless steel as a valve material, the chloride ion level must be less than 100 ppm.
Valve Seat Leakage Examination
The valve is entirely closed in this test, with the intake submitted to hydrostatic pressure and the valve body filled with the testing fluid at a specific temperature.
Leaks are detected on the valve’s outlet side. Pressure must be lower than the maximum permissible pressure of 110 percent at 100 °F. Pressure is typically given for one minute. The valve must not leak from the stem or packing in order to pass the test. A small amount of leakage from the disc and seat sealing surfaces is acceptable.
Inspection Of The Pressure Safety Valve
With the pressure safety valve removed, the inlet and exit pipework are observed during this valve check.
The following components are examined for signs of corrosion, deposit buildup, cracking, pitting, roughness, or other damage:
External aspect
Release nozzle
Flanges
Bellows and spring
Seat Valve Test
The valve is fully opened while the ends are closed for this test. Lower than the maximum permissible pressure at 100 °F is not permitted.
For valves smaller than 2 inches and larger than 2 inches, the testing time is 15 and 60 seconds, respectively. The packing gland is carefully examined while undergoing the backseat test pressure during this procedure. If there are no leaks from the packing gland or the valve, it passes.
Why Is Valve Testing Necessary?
Precision control valves are essential for the smooth and safe operation of industrial processes and equipment. When valves most efficiently regulate process factors such as temperature, pressure, and flow, the production quality is best.
Valve performance testing supports both product quality and (most importantly) safety. Several plants or refinery explosions have been blamed on valve failure. To ensure safety, we adhere to established norms and industry standards.
Common Butterfly Valve Failure And Ways To Fix Them
The rubber elastomer within high-performance butterfly valves is the component that fails the most frequently. After prolonged usage, it may rip, wear out, perforate, or even come off. Therefore it becomes important to have knowledge about the butterfly valve connection for efficient repairing.
The butterfly valve repair that is required on-site cannot be met by the traditional thermal vulcanization process. It takes time and effort to fix with specialized equipment since it uses a lot of heat and power. Today, we use an inventive way to progressively replace old processes with polymer composite materials.
Their products’ exceptional adhesion and high durability against wear and tear ensure that the repair cycle may match or even surpass the lifetime of the original parts and greatly cut down on the amount of time needed for repairs.
Place the valve in the cavity to clean it before installation, making sure that the performance of the goods produced in our plant and the medium’s flow direction meet the circumstances under which it functions. No external objects may be fastened to the butterfly plate or sealing ring.To prevent harm to the sealing ring, the butterfly plate may be closed.
It is advised to utilize the HGJ54-91 socket weld steel flange, which is designed specifically for disc valves. The location of the installation in the pipeline. Although vertical is the preferred posture, it cannot be turned around. The course of usage will need adjustments to this flow. The flow rate is controlled by a worm gearbox.
Remove the worm gearbox lid after about two months for the valve on the disc with longer closing and opening times. Make sure you have enough butter by checking to see if the quantity is still in excellent shape. Check that the connecting parts are solid to ensure the filler’s bee and that the filler can freely move the valve stem.
How Can Difficulties With Butterfly Valves Be Avoided?
The bulk of problems with swing check valves or butterfly valves is due to improper installation, not the valve itself. In order to reduce butterfly valve maintenance concerns, it must be emphasized that butterfly valves must be placed properly during the commissioning procedure. The seal’s elastomer composition is one need that must be looked at during installation.
When you install it, it tends to travel toward the surface of the valve and then becomes crushed. As a result, its effects won’t last long and the valve won’t perform as intended by sealing valve when it’s open. In order to avoid hiding the sealing material, attention should be given when fitting the valve.
Another circumstance is when discs are near to the valve and stick out from the body. It is crucial to verify that the disc may freely rotate as it enters the valves.
Butterfly valves are often fitted with the stem vertical and the actuator situated vertically directly above it. Butterfly valves should be installed at least six pipe diameters apart from other line elements like elbows, pumps, and other valves. If this cannot be accomplished, valves should be placed as far away from these elements as practicable.
Finally, if a butterfly valve is linked to a check valve, leave enough space between the two to ensure that the movement of the butterfly valve disc does not interfere with the operation of the neighboring equipment.
Butterfly Valve Assembly And Installation Guide
Clean the lug-type butterfly valve from top to bottom. To aid in installation, apply the silicone-based base oil or any other lubricant.
Put the bearing bush within the valve’s body.
Your seat should now be in the valve body. For simple pipe movement, make sure the openings in the body and seat are lined up.
Place a disc within the valve seat with the stem holes facing in the proper direction and the taper pin holes pointing up towards the top of the valve plate.
O-ring for packaging installation.
Install and screw the packing gland into place.
Put the bottom cover in place.
Taper pins should be inserted into the holes on the disc that match the holes on the stem. Firmly tighten them.