How to Keep your valve new

What is a valve?

A valve is a piping system component that controls the flow of the fluid through the system.This is accomplished through the manipulation of an obstructer within the valve.

Actuated valves use mechanical devices known as “actuators” to control the valve with a power source such as compressed air or electricity.

Most actuated valves are also available in a manually operated version or with a manual override.All of the most common types of automated valves are classified into one of three groups: self-actuated, linear and rotational.

Within each of these categories, there are various valve types, each with its own set of advantages. It regulates the flow and pressure of system or process fluids by carrying out any of the following tasks:

1.Reversing and accelerating water flow

2.Changing (throttling) the rate of flow

3.Direction of water  flow regulation

4.Controlling the pressure of a process or downstream systempressure relief for a component or pipe.

Many  types and designs can fulfill one or more of the above purposes. A wide range of industrial applications are reliably accommodated by several valve types and designs.

Valve Parts

 The body, bonnet, trim (internal elements), actuator, and packing are the core components of all valves, regardless of type. as shown in the figure 1

Valve body

Is the primary pressure boundary of a valve. It serves as the principal element of  its assembly because it is the framework that holds everything together.

Valve Bonnet

A valve body closure component that contains an opening for the stem.

Valve Trim

The internal element of a valve are collectively referred to as a valve’s trim.The trim typically includes:

Disc: The part of the valve which is positioned in the flow stream to permit or to obstruct the flow.

Seat: The portion of the valve against which the closure member presses to effect shutoff.

Stem: which connects the actuator and disk, is responsible for  the disk positioning.

Valve Actuator

A device that operates  the valve by utilizing electricity, pneumatics, hydraulics, or a combination of one or more of these energies.

Valve Packing

To stop leaks from occurring in the area between the stem and the bonnet, most valves employ some sort of packing. It will leak if its packing is too flimsy, which is dangerous. If the packing is overly tight, the movement will be hampered and the stem could be harmed

Different Valve Types

 Many designs have been evolved as a result of the diverse habitats, system fluids, and system situations in which flow must be controlled.

 If one has a basic awareness of the distinctions between the various types of valves and how these differences affect its function,It will be easier to assure correct application of each  type during design and proper use of each  one during operation.

Rising stem (multi-turn)

Gate valve

 A gate valve has a linear motion  that is used to begin or halt the flow of fluid ; it does not control or throttle the flow. The name “gate” comes from how the disk appears in the flow stream.

 When a gate valve is fully opened, the disk is entirely withdrawn from the flow stream. When it is is open, this feature provides essentially negligible flow resistance. As a result, the pressure loss across an open gate valve is minimal.

A disk-to-seal ring contact surface exists for 360 degrees when the valve is fully closed, resulting in effective sealing.

When it is closed, there is little to no leakage across the disk when a disk is properly mated to the seal ring.

The flow route enlarges upon opening the gate valve in a highly nonlinear manner with regard to the percentage of opening.

This indicates that the flow rate does not alter consistently when the stem moves. A partially open gate disk also has a tendency to shake because of the water flow.

If utilized to regulate flow, the majority of flow change occurs near shutdown with a very high water  velocity, leading to disk and seat wear and eventually leakage. Gate valves are not employed to control or throttle flow due to these reasons.It also can be used with a wide range of fluids and, when closed, offers a tight seal.

Advantages of gate valve

1.It has good shutoff characteristics.

2.The pressure loss  is minimal.

Disadvantages of gate valve

1.It is not suitable for throttling applications.

2.It is prone to vibration in the partially open state.

3.It is more subjected to seat and disk wear than a globe valve.

4.Repairs, such as lapping and grinding, are generally more difficult
to accomplish.

Globe valve

 Is frequently used to control fluid flow, is made up of a valve body with a circular disc inside of it that moves parallel to the disc axis and makes contact with the seat.

In general, the stream travels upward through the seat area up against the disc, changing direction to travel through the body to the outlet disc, with the exception of vacuum service or as mandated by system design (such as fail closed). Either a flat or tapered seating surface is possible.

Addvantages of globe valve

1.Good shut-off capability.

2.Moderate to good throttling capability.

3.Shorter stroke

4.Available in tee, wye, and angle patterns, each offering unique capabilities

5.Easy to machine or resurface the seats

Disadvantages of globe valve

1.Higher pressure drop

2.Requires greater force or a larger actuator to seat the valve(with pressure under the seat)

Needle valves

For one thing, they are smaller and allow for finer flow control on smaller lines.Instead of a disc-shaped plug, they employ a “needle” with a conical shape that moves in and out of an orifice.While useful as an on/off switch, these are not the best option.

Needle valves are designed for precise flow control.

Rotary valves

Rotary valves are also known as “quarter-turn” valves.Quarter-turn valves provide a full range of motion with a 90-degree handle turn.This makes them ideal for situations where speed and ease of opening and closing are more important than precision. It includes:

Ball Valve

Both plug and ball valve are  one-quarter turn valves, but the plug in a ball valve is spherical as opposed to tapered or cylindrical.

Typically, ball valves block flow by acting as block valves. They work well in situations where fast on/off or bubble tight service is required.

Although all-metal, high-pressure ball valves are available, most of them have an elastomeric seating material that offers good shutoff characteristics.

Advantages of ball valve

1.Quick to open and close.

2.Smaller in size than a gate valve.

3.Several designs of ball valves offer flexibility of selection.

4.High-quality ball valves provide reliable service in high-pressure and high-temperature applications.

5.Force required to actuate the valve is smaller than that required for a gate one.

Disadvantages of ball valve

1.Conventional ball valves have relatively poor throttling characteristics. In a throttling position, the partially exposed seat rapidly erodes because of the impingement of high velocity flow.

Plug valves

Except for the shape of the obstructer used, the basic construction of a plug valve is nearly identical to that of a ball valve.A slightly tapered cylinder replaces the ball in this case.

This cylinder, like a ball valve, has a bore through it and operates in the same manner, being open in one position and closed when rotated 90 degrees.

Plug Valve

Plug valves have advantages that make them the preferred choice in certain applications.One advantage is that they have no voids or cavities where media can become trapped.

Another advantage is that they can be adjusted to repair leaks that may develop over time, whereas ball valves must be repaired or replaced.

Plug valves, like ball valves, are typically used for on/off applications.They are oftenused in corrosive environments, such as those found in refineries and chemical plants.

Butterfly valve

Butterfly valves, as opposed to the ball and plug valves, use a disc-shaped obstructer.“Resilient seated” butterfly valves are the most basic, general-purpose butterfly valves.

They have a single seal ring that serves as both a seal between the valve body and the disc and a seal between the pipe flanges and the valve body.The flow is stopped when the disc is perpendicular to the direction of flow.

When the valve is rotated 90 degrees, the flow travels around the disc’s slim profile, passing through the valve.They are often used on larger pipe sizes where a ball or plug valve would become too large, expensive and heavy.

They can also be used as a flow control valve or an on/off valve.When using a manual actuator in a flow control application, it must lock into place so that the fluid force does not rotate the disc in either direction.This feature is present in the majority of manual butterfly valves.

Advantages of butterfly valve

 1.The compact design requires considerably less space, compared to gate, globe, or other valves.

2.Light in weight.

3.Quick acting; as a quarter-turn valve, it requires less time to open or close.

4.It is available in large sizes, ranging from NPS 1¹⁄₂ (DN 40) to over NPS 200 (DN 5000).

5.It has low-pressure drop and high-pressure recovery.

Disadvantages of butterfly valve

1.Throttling service is limited to low differential pressure.

2.Cavitation and choked flow are two potential concerns.

3.The disc movement is unguided and affected by flow turbulence.

Check Valve

Check valves are made to stop the flow in a piping system from switching directions. The material traveling via the pipeline opens these valves.

Any reversal flow  closes the valve, which is opened by the pressure of the fluid moving through the system.

The check mechanism’s weight, back pressure, a spring, or a combination of these methods can all be used to close the gap.

Advantages of check valve

1.It is self-actuated and requires no external means to actuate the valve either to open or close. It is fast acting.

2.It allows flow in one direction only.

3.Pressure drop is very low.

Disadvantages of check valve

1.Since all moving parts are enclosed, it is difficult to determine whether the valve is open or closed. Furthermore, the condition of internal parts cannot be assessed.

2.Each type of check valve has limitations on its installation configurations.

3.Disc can stick  are in an  open position.

Diaphragm valve

Diaphragm Valve

A linear motion valve called a diaphragm valve is employed to initiate, control, and stop fluid flow. The name comes from the flexible disk’s ability to seal by mating with a seat that is situated in the open space at the top of the valve body as shown in the figure

Advantages diaphragm valve

1.Because of its straightforward construction, it is disassembleable in the event that the diaphragm or other components need to be replaced.

It is possible to employ corrosive fluids since there is no contact between the fluid and moving parts. As there is no direct touch, it can also be used with abrasive fluids, which significantly reduces wear and tear.

2.Good performance with a small pressure drop, a crucial consideration when selecting valves for demanding applications.

3.Hazardous chemicals and radioactive fluids can be handled easily thanks to a diaphragm valve’s chemical resilience.

Disadvantages diaphragm valve

1.The diaphragm material imposes a limit on the working temperatures and pressures. Typically, temperatures and pressures are restricted to 200 psi (1380 kPa) and 400 F, respectively (204 C).

2.Compared to other valves, the size range is constrained and is typically NPS 12 to 12. (DN 15 to 300).

3.Not recommended for vacuum services. If not properly maintained, diaphragm valves can become blocked with debris over time which will affect its performance.

Valve Type Selection

The choosing of  the valve type should consider:

1.Required function.                                                 2.Service conditions.

3.Fluid type and condition.                                       4.Fluid characteristics.

5.Frequency of operation.                                         6.Isolation requirements.

7.Maintenance requirements.                                    8.Environmental considerations.

9.Past expereince in comparable conditions.            10.Weight and size.

11.Cost.

Industrila valve testing

Why is testing essential?

Precision-operated control valves are essential to the efficient and secure operation of industrial processes and machines.The highest level of production value is achieved when valves correctly control process variables including temperature, stress, and movement.

Product quality and, more importantly, security are improved through valve testing and performance monitoring.

Valve failure has been implicated in a number of explosions in factories or refineries. They follow accepted standards and guidelines set by the industry in order to ensure security.

Industrial valve testing techniques

1.Pressure test method(Globe valve)

The globe and throttle valves are typically placed in a pressure test rack, the valve disc is opened, the material is pumped to the specified value, and the valve body and valve cover are checked for sweating and leaking during the strength test.

 A single piece may also be subjected to the strength test. In the sealing test, only stop valves are used.

The valve flap is unlocked, the valve stem remains perpendicular during the test, and the medium is fed to the specified value from the underside of the  valve flap. After passing the test, close the valve flap and release the other end of the valve to look for leaks.

While conducting either one or both of the valve strengths and constriction tests, the stress should be reduced to the proper tightness test value, the packers and gaskets should be checked, and then the valve flap should be closed and the outlet end opened to check for spills on the sealing surface.

2.Pressure test method (Gate Valve)

The gate valve and globe valve both pass the ultimate strength test. There are two techniques to perform the gate valve sealing test.

1.You can either introduce the test medium to the indicated value directly into the plug on the valve cover to increase the pressure inside the valve to the predetermined value, or you can open the gate, close the gate, and immediately remove the gate valve to check the gaskets on both sides of the gate for leaks.

The above method is known as the test of intermediate pressure. For sealing tests on gate valves with nominal diameters less than 32 mm, this method is useless.

2.Another method to raise the test pressure of the valve to the recommended level is to open the gate, close the gate, and open the blind plate at one end to check if the sealed surface is seeping.

The aforementioned exam should be repeated until it is successful. Prior to the gate sealing test, a pneumatic gate valve packing and gasket sealing test must be carried out.

3.Pressure test method (Butterfly valve)

The pneumatic butterfly valve strength test and the globe valve strength test are comparable.The test material for the butterfly valve’s sealing production must come from the media’s inflow end, the butterfly plate must be open, the other end must be closed, and the injection pressure must meet a specific value.

Once the tight seal and other seals without leakage have been tested, the butterfly plate must then be closed, the other end must be opened, and the butterfly plate must then be checked. If there is no leaking at the seal, it passes. It is impossible to check the seals on the butterfly valve that regulates the flow.

What are the controlling factors of the valve’s life? 

Seal quality, operating frequency, and environmental conditions all affect valve longevity.If the seal is working properly, the Valve is working properly as well. Finding the right seal ensures higher performance and long operational life.

Other aspects to consider are the pressure, the temperature, and the media type. It is recommended that valves be maintained every three months if used continuously.

Do yuo know how to keep your valve as good as new?

Start by comprehending valves. Everything necessary, from the valve design to other parameters, is contained in the valve body. It is essential to read the instruction booklet included with the valve. It includes all required details including material, pressure, and temperature.

1.Double-check that you are choosing the right valve. Although it is a tedious process, it is necessary, as we are aware. factors such the type of media, its temperature and pressure operating ranges, and its open or closed posture.

2.Incorrect installation could cause the valve to completely fail. Valve malfunctions can be caused by faulty alignment, loose end caps, inadequate insulation from factors that can rust the system, etc.

3.Ensure that the system is regularly and thoroughly cleaned. To clean the valves, use the appropriate tools, such as a clean cloth, brush wires, and grease.

Unclean valves can cause the transfer of foreign materials that can obstruct the flow of the medium if they are fixed with piping systems.

4.Careful research must be done to select the ideal elastomer to cover the valve in order to protect it from unfavorable situations, such as high temperature, pressure, and corrosive media.

5.For a healthier valve, frequent maintenance, preventive measures like selecting a non-corrosive material, and methods like field machining to check for leaks should be carried out.

 6. Recommended practices: To install and maintain the system, qualified professionals and staff are required. Various          national, regional, and municipal laws should be observed.

 Don’t be afraid to do your research before making a pricey buy. Most importantly, it’s critical to comprehend that a valve is susceptible to wear and tear over time despite having a robust constitution. Therefore, it is preferable to look after them and take precautions in advance.

Valve maintenance procedures

Clean it

One of the simplest ways to increase the lifespan of your valves is to clean them. Although everyone’s cleaning cycles are different, it’s a good idea to clean your valves at least once a year.

If your surroundings are dusty or dirty, you should clean them more frequently. The simplest approach for cleaning the valve casing is with a wire brush or towel.

If you keep it clean, you can avoid accumulating on the valve stem and other working parts, which will extend its lifespan.

Assessments on aregular basis

You should regularly check and inspect your valves. The frequency of monitoring should be higher for valves under heavy stress (temperature or force). A valve will fail faster when it is pushed past its breaking point.

Make sure the enclosure has adequate ventilation. Verify that all fasteners—bolts, nuts, and other hardware—are held in place firmly. Open and close the valves as frequently as you can to make sure they’re not stuck. Leaks should be immediately fixed if you find any.

Leaking valves frequently result in fugitive secretions. Leaks can be discovered right away by mineral deposit or corrosion on the casing. Test valves that are typically static to ensure the valve position indicator is generating an accurate signal.

Routine shutdown maintenance

The components inside your valves will corrode over time as a result of mineralization, tarnish, and wear. Valve inspections are best done during machine shutdowns. They should be disassembled, cleaned on the inside, and any broken or damaged parts repaired.

Together with metal components, a variety of rubber and plastic parts might need to be replaced. Replace any broken or rotting parts as necessary if you locate any.

Lubrication

Oiling is one of the simplest and least expensive valve maintenance procedures. If you skip this process, you could have convulsions or, at the absolute least, see a decline in performance.

Repeated lubrication can also aid valve seal, extending their useful life. The important step is to turn the valve so that lubrication may get into the valve cavity.

As a result of less wear, the valve’s life will be prolonged. You must choose the proper lubrication for your unique valves based on the setting when doing valve maintenance. Never simply take the first thing you see. Lubricants have a variety of characteristics.

Lithium-based, resistant to high temperatures, impervious to carbon dioxide, and other characteristics are all possibilities. When clay or other solid-based thickening agents are added to stick-type lubes, for example, they may harden and leave solids in the valve, causing the clutch to engage.

In addition to lubricating, you might also need to shield your valves from air temperature variations, especially if the pipes are on the outside. If so, you might need to add and maintain protective insulations as part of your routine valve maintenance.

Repairs duration time

1.Internal Leaks: Because the Valve cannot be entirely closed, an internal leak is unavoidable. International standards set a maximum leakage for each type of Industrial Valve. Leakage that is greater than the allowable amount is a surefire indication that the valve needs to be fixed.

2.External Leaks: There may be a number of factors for exterior leakage. As observed in several instances, the first is improper upkeep and ignorance. Another possibility is that Valve and the media materials are not the same. External leaking might also be brought on by high temperatures.

3.Noisy Valve: “Water hammer” is the term used in industrial settings to describe noise produced by valves. This indicates that the Valve needs to be replaced or serviced. The disc crashing into the valve seat is what’s making this noise.

4.Standstill: It is clear that a valve needs to be repaired or retrieved when it stops working. Some valves can be repaired, while others need to be totally replaced.

Importance of ball valve maintenance

In spite of the fact that investing in a strong, high-quality ball valve can greatly reduce maintenance and repair expenses, it is still crucial to maintain proper maintenance.Manufacturers frequently overlook the crucial role that maintenance plays in extending the lifespan of the ball valve.

They are susceptible to depreciation over time, much like other machinery and equipment.Failure to prioritize maintenance will drive up the cost of replacement when the ball valve stops working. The following are some of the factors that make ball valve maintenance crucial:

1.The Valve’s Effectiveness

Ball valves can lose some of their ability to efficiently move fluids when used over extended periods of time. By extending its lifespan and providing ideal working conditions, maintenance can solve this issue by reducing friction during prolonged use.

It is easy to see how opening and closing might become a painful experience over time. Possible causes include dry seals. Maintaining the components in usable condition is essential to preventing emergencies in production regions.

2.Operational Safety

Since prevention is always preferable than treatment, the first step in preventing an emergency is to make sure that routine maintenance of machinery and equipment is not disregarded.

It guarantees both the workers’ and the setting’s administrators’ safety in addition to the working environment’s protection.

Neglecting this region may open the door to risky scenarios that could result in serious injury, vision loss, and possibly even death.

3.Cost Savings

Many producers and facility owners attempt to cut expenses by sacrificing maintenance. Nonetheless, a large amount is spent on repeated replacements as a result of neglecting maintenance, according to numerous studies.

 One may say that maintenance increases the lifespan and effectiveness of ball valves. The potential costs of replacing the ball valve as opposed to repairing it are significant.

4.Negative Emissions

A frequent occurrence in industrial settings with subpar functioning standards is fugitive emissions. Ball valve maintenance mistakes are at blame for about 60% of the dangerous pollutants.

The protection of health and the security of everyone involved are two other advantages that can be obtained from routine maintenance and prompt repairs of ball valves.

5.Survival

Ball valve owners can put up with the burden of frequent replacements when maintenance is taken care of. They drastically lessen the need for prospective repairs and save a ton of money on new bulk orders. Ball valve maintenance is essential to minimizing downtime and keeping costs under control.

Leaking valve repair steps

Leaks are a typical occurrence, particularly in an industrial setting. This may occur for a number of reasons, including improper fit, uneven surfaces, and stem pressure.

Ball valves frequently leak around the location of application, typically near the stem. The nut and packing washer are two parts that make up the airtight sealing. Heavy leakages could ensue from any obstruction in this location.

Fixing this location by doing the following procedure can also assist in preventing future leaks as the stem passes through them:

Materials Required

 1.Multi-purpose Screwdriver             2.Adjustable wrench

3.Packing washer                                4.Screw

 5. Replacement parts                         6.Lubricant

 7.Sponge                                            8.Procedure

Separate the handle and nut to make valve replacement easier. Reassemble after finishing the ball valve repair. A leaking valve can be fixed in the following manner:

Step 1: Shut Off The Water System

Turning off the water distribution supply is the first and most important step. As a result, there won’t be any water leaks while the ball valve is being fixed.

Make sure there are no drops coming out of the handle and turn it off fully. Drain the remaining water and sponge-dry the valve. With a screwdriver, remove the handle. The valve should then be completely disassembled.

Step 2: Disassemble The Valve

Disassembling will allow for a detailed examination of the parts and the precise source of the leak. Once the issue has been located, get the ball valves’ replacement parts ready. Keep all the parts safely together in one location for quick assembly.

Step 3: Replace Worn Parts Of The Ball Valve

To avoid any potential damage from friction, make sure the parts are completely lubricated before replacing the broken component.

Ball valve parts can be assembled in the correct order and without missing any by assembling them in reverse order. Petroleum jelly can be used in place of a proper lubricant if one is not available.

Step 4: Open The fluid Supply

Open the fluid supply gradually and slowly to see if the components survive the high pressure. If they comply, the procedure has been carried out successfully.

Advantages of Maintenance of Valve

1.Making sure your valves are in good working order and enhancing security.
2. Reducing the Need for Shutdowns.
3. Saving  Money.
4. Eliminating Fugitive Secretion.

References

[1] https://egvalves.com

[2] https://en.siovalve.com

[3] https://kh.aquaenergyexpo.com

[4] https://kh.aquaenergyexpo.com

[5] https://kh.aquaenergyexpo.com

[6] https://kdvflow.co.uk/news

 

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