A Ball valve is a shut off mechanical device that is used to control the flow of liquid or gaseous substances by means of a rotary ball that has a hole in it. Ball valves are one of the most effective and reliable kinds of valves.
A lot of industries make use of ball valves due to its durability and safety. Ball valves limit the chances of plumbing hazards and puts risky situations under control, especially in cases of leaking pipes. The ball valves can easily be used to turn the entire plumbing system on and off. So, if ball valves are used to control piping systems, what then is used to check and avoid leakages in the ball valve itself?
This article guides you to every information you need to get the most out of a ball valve, inspecting ball valves, avoiding leakages, and how to repair ball valve leaks should they occur.
Please Check Beforehand
Before purchasing your industrial ball valves (as applied to every other thing), a thorough inspection and ball valve test should be carried out to certify them suitable for operation. This is because using the wrong ball valve can cause a lot of damage. To inspect, check that the ball valve ticks the following:
- Proper Ball Valve Type
First and foremost, what is the ball valve needed for? Where and what will it be installed on? These questions must already have been answered before even deciding to buy the ball valve as the application of the valve determines the type that should be purchased.
Buying the proper valve type is a step towards ensuring a proper working piping system. There are different types of ball valves with each valve having its own suitable applications. Even for ball valves that can be used across a wide range of applications, there is always a particular one it is best compatible with.
To ensure ball valves do not eventually leak after the installation process, it is necessary to buy the most ideal ball valve to fit right in with no difficulty.
The major types of ball valves are:
- Full-note ball valve
- Standard Port ball valve
- V Port ball valve
- True Union Ball valve
- Motorized ball valve
- Manually Operated ball valve
- Sanitary ball valve
- Leakage Intolerance
One of the major things to look out for when inspecting a ball valve before purchase is its Intolerance to leakages.
Ball valves are made with different materials and under different conditions, only the ones made from the finest of materials described as being resistant to corrosion should be considered.
A ball valve’s intolerance to leakages is a clear pointer of how long the valve will be available for active use until it can no longer resist the corrosion and starts to leak.
- Operating pressure limit
To avoid leakages in the future, the operation limit of the system should not exceed that which the valve is capable of handling. Usually, when the system’s operating pressure gets to about 80-90%, the pressure relief valve starts to exhibit signs of weakness.
Every valve has an operating pressure rating, this is called the Maximum Allowable Working Pressure (MAWP).
The MAWP is the maximum amount of pressure that the valve will let flow through it; this is referred to as the “set first pressure.” When a ball valve is being pushed beyond its limits, or used in pressure conditions higher than the ball valve’s pressure rating, this will affect some crucial parts of the device such as the diaphragm, o-rings, springs and the general operability of the valve.
All ball valves have their own different pressure ratings (indicated in PSI) and only a ball valve with compatible pressure power should be applied to work.
Common Ball Valve Leakage And solution
Now, let’s look at a number of ball valve leakages that are the most common, their possible causes and how to fix them easily.
Leakage between Actuator and Valve
In situations where score marks can be seen on the surface of the disc, this confirms that the disc was not fitted correctly in the first place. For every time the ball valve’s seat layer lining closes when there is a leakage inside the valve, a potential leak is created. This would eventually get worse if left unattended thereby reducing the ball valve’s lifespan.
If the leakage gets to a certain damage level, there would be no point in repairing it and the liners of the ball valve seat will eventually need to be changed.
- Possible cause
A likely reason for the leakage between the actuator and valve is that some of the fitted balls were either too big, or too small. An undersized or oversized ball could cause a lot of damage to the valve.
In order to avoid this, it is a must that only valves with the appropriate size and volume grade should be installed. Mistakes or carelessness that occur during ball valve installation could cause a huge problem later on during operations, the worst of which is valve leakage.
- How to fix
When a leakage is discovered between the actuator and ball valve, follow these simple ball valve repair steps for a quick fix:
- Make sure to clean the packing hole.
- Replace the packing.
- The actuator should be thoroughly lubricated.
- Clean the ball valve’s seats and I’d the stem is difficult to operate, you might need to change the seat altogether.
- Tighten the nuts well, also apply Loctite or thread lock to it.
Shut-off Failure
If there is an issue with any part of the plumbing system in the house or in an industrial setting, the first sensible thing to do would be to close it off from the ball valve. However, when the mechanical part that is supposed to work as a shut-off device is the one with the problem, then there is a problem.
When a ball valve is not exercised regularly or left for a long time, it is very likely that it will leak some amount of water when eventually closed.
- Possible Cause
A ball valve that has been in operation for a long period of time without being exercised will not be able to hold back the contents of the pipe as well as it should. This is worse if there’s already an issue with the sealing in the valve.
When.
- How to Fix
To resolve the issues of a shut-off failure in ball valves, the following instructions are very helpful:
- Use a pair of pliers to tighten the valve’s fittings.
- If the leaking does not stop after following step number One, proceed to replace the seal I side the valve with a new one.
- You might need to change the valve if the above solutions don’t work.
Leaks When Closing
With time, the gaskets inside the ball valves may become very hard or get covered in mineral deposits. This is because the shut-off valves are rarely utilized. After closing and opening the valve, the gasket may not be able to seat well. This will eventually lead to a leak close to the valve seat crowd.
- Possible Cause
The major cause of a ball valve leakage when closing is leaving valves in one position for a very long time. Sometimes, leaks when closing can also arise as a result of either using an undersized or oversized ball valve.
- How to Fix
Do the following to fix leaks that occur from closing a valve:
- First of all, cut off the main supply that leads to the faulty valve.
- Make the cap of the leaky shut-off valve lose with the help of a torque wrench.
- Apply Teflon wrapping on and around the spindle.
- Without over-tightening the nut, screw the cap nut back into its place.
- Now carefully open the valve again to confirm it now works without leaking.
Leaking From Seat Seal
Leakages in the seat seal of ball valves are the most common cases of leakages in valves. Under certain circumstances, class 3 valves may need to operate with soft valve seats in order to have a maximum leakage tolerance of 0.1.
- Possible Cause
The seal becomes very dry and generates a lot of heat when it is not lubricated for a period of time. The pressure created from the friction that ensues from the heat and dryness will eventually burn and shatter the seal, therefore allowing fluid some escape space. In fact, a motor shaft seal that is used in operations while dry will leak after only a few uses due to heat splits or burns.
- How to Fix
To fix leakages in the seat seal of the ball valve you will need to,
- Use a wrench to disconnect the shut-off valve from the supply line.
- Peel the curved coverings of the closet screws. If this is not done, the hex nuts will not be able to separate.
- Remove the wax seal from the closet lip.
- After removing the nuts, a repair ball valve leak strap should be put under the closet flange, this will help hold it to the ground.
- Ensure that the new waxed seal applies well to the closet flange.
- You can now install the newly fixed seal back to the bottom of the ball valve.
Leaking From Stem
With each passing use of ball valves, the valve stem may get very brittle and start breaking off. This will increase the chances of air seeping through and leading to a full-blown leakage. A ball valve stem leak is like a crack in the bottom of the valve’s body.
- Possible Cause
Ball valve stem leak can be caused by many things, but the use of bad quality chemicals and rust is one of the most common causes of valve stem leakage.
- How to Fix
For ball valve repair of a stem leakage, do this:
- Once the valve is confirmed to be faulty due to leaking, do remove and deflate the tire.
- Use the tapering edge of the valve core to wipe the valve stem. This should be done very carefully so as to keep the region debris free.
- You can now fix the repaired core back into the system.
Working Condition for Ball Valve
To control flow in a piping system, the ball valve uses a wrench handle and not wheel handles. To set the ball valve into full operation, the wrench will need to be turned 90 degrees right or left, depending on the position of the valve.
The device is closed when it is pivoted 90 degrees by the valve handle and is perpendicular to the media flow. It is open when the handle lies flat aligning with the flow direction which is also in line with the borehole.
Ball valves are widely used due to the wide range of work they can do when used under the right working conditions. They are characterized by a long service span and provide reliable sealing over this period of time even if not put to use for very long.
However, the efficiency of work done by the ball valves is dependent on several working conditions and properties. Some of the working conditions that need to be kept in mind are:
Pressure
The capability of a ball valve to withstand a certain level of work pressure depends on its pressure rating. Every ball valve has its own specific working pressure, ball valves should not be used under pressures that are above their indicated pressure rating.
It is necessary to confirm that the valve is able to withstand the lowest and highest pressure levels before installing it in the system. This can be done by reviewing and checking the ball valve’s data sheet for its appropriate pressure range.
Temperature
Only suitable ball valves should be applied for certain working conditions. Ball valves that can withstand the minimum and maximum temperature levels experienced the required operations. For example, there are specific low pressure and temperature ball valves best suited for low pressure applications like LNG and LPG.
Materials
Materials play the most important role in the working conditions that a ball valve can be applied to. The material ball valves are made of also, to a large extent, determines their pressure and temperature tolerance. For example, ball valves made from stainless steel usually have the highest pressure rating and are able to withstand maximum pressure. Brass and PVC materials also follow closely in pressure tolerance.
The body and seal material of a ball valve also determines its pressure range. Different materials with their varying temperature range can be found on the ball valves’ datasheet provided by industrial valves manufacturers. However for context purposes, some of the common ranges have been provided below;
- Stainless steel ball valve: from -40° Celsius to 220° Celsius (-40°F to 428°F).
- Brass ball valve: from -20° Celsius to 60° Celsius (-4°F to 140°F).
- PVC ball valve: from -10° Celsius to 60° Celsius (14°F to 140°F).
Furthermore, to get the absolute best working conditions out of your ball valves, you should take note of these two properties in them:
1. Rangeability
Rangeability is simply the maximum flow rate to a minimum which can be controlled by a particular type of ball valve. The geometry and actuator of the ball valve are what are used to calculate a valve’s rangeability. Should the valve be not accurate with its stroke at 5%, this simply means that its rangeability is 20:1, that is, 100% divided by 5.
The valve is able to control a wider range of flow rates with every increase to its rangeability. The flow rate performance and performance of ball valves differ according to the types of valves.
Valves with a higher rangeability indicate that when the closing element is almost closed, its sensitivity is usually lower, and increases with the opening of the valve.
2. Flow
Ball valves have several functions and capabilities, some of which are opening and shutting off passage to flow, throttling, or regulating the flow of media through a piping system.
Valves can get different flow directions, some single, some multiple. It is the shape of the valve that will determine the number of directions the flow of a valve can go. The number of directions a flow can go also depends on the number of ports a ball valve has. The ports in a ball valve range from 1 to 4 and are either L-shaped or T-shaped.
L-shaped Ports: this type of port allows for just a single direction at a time and is mostly used to function as a diverter valve. The center of the port can be used to control the direction of flow to go to any side of the valve, only that it can not directly flow to both sides at the same time. The smooth surface of L-shaped ball valves makes it possible for a very tight seal in the valve.
T-shaped Ports: The T-shaped port ball valves are multi-directional allowing flows to two directions at once or in one direction only while the other side is shut off.
Storage Condition for Ball Valve
To ensure that ball valves stay in perfect factory-fresh conditions, they should be properly stored under the right conditions. Ball valves must be kept indoors in a dry and well-ventilated space.
The storage facility should be weatherproof, fire resistant and void of direct sunlight. The room atmosphere should be at a cool temperature of -4 degree Celsius low and 30 degrees Celsius. Corrosive chemicals should be absent from storage space for ball valves.
For cases of long-time storage, the space should be inspected at least once every 4 months to make sure everything is in good condition. If an actuator had already been mounted on the valve before the storage stage, it is recommended that the actuator should be cycled every 30 days on average.
Attention must be paid to make sure that during storage, ball valve handles are left in completely open or completely closed positions. This is done so as to prevent cold deformation on the sides of the valve’s seal seats. All bare metal has to be covered with a rust inhibitor that is suitable for it
While in storage, ball valves must also not be exposed to dust and dirt.
Maintenance Tips
Practically, ball valves are low maintenance mechanical parts, it does not take too much to keep them in the right shape. The main maintenance required for ball valves does not really exceed free-turning the valve with lubricants and keeping the valve clean. However to be more specific you can follow these easy steps.
- Regular Cleaning
At intervals, use a clean towel to wipe dust, oil and dirt off the valve casting. You can also use a wire brush to remove build-ups that come from moving parts or the valve’s stem.
Ball valves should be cleaned at least once every year but if it is installed in a dusty environment, cleaning intervals can be much shorter. Ensure that only cleaning agents that won’t damage the valve materials are used. Gas-based air cleaners are ideal for metal components, whole water or alcohol-based cleaners work very well for non-metal parts.
If there is little or no chance for debris to build-up in the ball valve, it will not impact your piping system’s performance negatively and the valves in turn tend to last longer.
- Valve Lubrication
Make sure to lubricate the valve regularly using water-insoluble, synthetic and oil-based lubricants. Clay or solid-based lubricants should be shunned because they may cause build up of debris inside the valve cavity.
Only lubricants that are compatible with the system media and your valve’s material should be chosen. If applied properly, lubrication helps to make the valve seals more effective, it also enables the ball valves to operate smoothly while preventing abrasion.
Bottom Line
Everything you need to know about ball valve leakages has been highlighted in this article. We discussed points to look out for during ball valve test and inspection, this is done so that users and buyers of ball valves will understand the leakage faults in them. Do ensure to always check for everything explained in this article when purchasing ball valves and also how best to maintain them. If you want to buy ball valve, feel free to contact us.
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