A ball valve operates with a sphere in place of a handle or stem, sitting within a pipe where water flows.
When the operator turns the handle or stem, it can close off (shut) either direction from the center of the spheroid.
The fluid passes through the central hole inside the sphere as directed by other openings around the surface of the sphere. Only one opening need be provided for there to be flow in one direction, and it can be closed by a plug inserted into this opening.
A second opening must be provided for return flow, and will remain open unless/until something prevents it from being plugged. This is what allows the pressure below the valve to drop during operation.
During startup, before the system depressurizes, the lowermost diverter arm has not yet lifted out of its seating. The bottom port goes unused until the tank is fully pressurized. It serves only to accelerate depressurization.
The operation of a ball valve
A ball valve is one of the most fundamental components in your pipeline system. It controls water flow by rotating a round metal plug that has holes drilled into it. When the hole are aligned with each other, water can pass through. Otherwise, it will stop all water flow.
Ball valves have two modes: open or closed. In the open position, there is an opening linked to the outlet for water to escape. You can see the open position next to the closed position below.
When the ball sits in this position, it shuts off the fluid passage. This is the closed position.
There is another mode you can set on some ball valves; this is the bypass position. In this case, instead of shutting off the fluid passage, it opens a new channel going somewhere else.
This allows waste products from production to go outside rather than being cleaned up. To enable this, just move the ball away from its intended seat located at the bottom of the passage.
To make things more complicated, there may be restrictions preventing the valve from moving back and forth simultaneously. In this case, only part of the movement is available for use.
Advantages of a ball valve
A ball valve operates by having a round, usually brass, sealing ball float in place at the orifice of a pipe. The pipe is closed at both ends, so it cannot be drained through gravity. Instead, pressure from inside a pipe pushes water past the ball and out the smaller end.
The benefit of this type of stop is that there’s very little internal friction due to the rounded shape of the seat. There may also be less wear and tear because the flat surface sits closer to the wall than a circular one. To operate, you feed liquid or gas into the space behind the ball.
When the fluid reaches high pressure, it will eventually blow through the small opening created between the ball and the seating—but it won’t do so with much force. When draining, the ball helps reduce flow resistance but can impede full drainage if left for long periods of time.
Disadvantages of a ball valve
When you open a ball valve, fluid can escape in any direction. This is because there are no seals between particles such as gas or liquid.
The holes found in pipe interconnecting with each chamber create areas where liquids can collect without flowing into the next section.
Also, when fluids reach high temperatures due to certain processes (such as nuclear waste), they can expand violently releasing large amounts of energy. If this happens, only one type of valve will stop the flow : The butterfly valve.
But under some conditions, even it may fail to function correctly. That’s why we need more sophisticated valves that can compensate for small leaks and damaged area.
These compensatory valves have movable plugs that close existing openings while new ones form within the body of the valve. There you have it—compensating valving at its finest!
How do I know if I have a ball valve?
You would feel what’s called a “dead spot” where the fluid makes contact with the surrounding medium (in this case, air). This is due to the fact that liquid has no way to escape your pipe at that point. If you were to install pressure instruments into the opening of the pipe, they would sound hollow because there’s no travel or transmission of sound through the material.
You could also see bubbles coming out of the end of the pipe; this is evidence of a burp valve!
If you put your ear near the end of the pipe, you should be able to hear some background noise such as hum or wind blowing. With a remote listen receiver, you might be able to hear ticking from a clock outside the pipe.
Ensure you have a ball valve
A ball valve is used to control fluid flow. It has one open, round end that can be connected to another pipe or vessel. Another surface attaches it to the part of the system trying to push fluid out. The central moving piece with holes in it makes this possible.
There are two basic types of valves: plug type and disk type. In a plug type there is an internal piston head which can be either solid (non-fluted) or fluted. Fluted works better for long life cycles.
A screw thread size fits between the seating face and the outer edge of the hole in the centerpiece. This connects the inside and outside diameter of the stem. There may also be other features on top of the stem not mentioned here.
A spring sits atop the piston head, pushing it downward into the surrounding seat ring. If the stem passes through the seal, the lower portion of the interior becomes filled with fluid, preventing any escape.
The fluid pressure tries to lift the ball up off its seat. As more fluid escapes around the edges, the pressure drops, and the ball returns to close the valve.
It just takes patience to reopen the valve if needed. Reopening refers to removing the stem from the container and sliding it back down to create full communication between the inside and the outside.
This could mean removing residual material from the neck of the bottle when using nail polish remover or pulling medication residues
Keep your valves clean
A ball valve is one of the most essential components in any pipeline. If you have liquids flowing through your system, then you need to have at least one ball valve installed near the end.
A box or housing containing several balls stacked together is called a reed valve. However, reed valves are generally slower than ball valves.
Both reed valves and ball valves use seals to prevent pressure from leaking around the opening. Chemicals such as sulfur can damage these seals over time, so it’s important to keep them clean.
Reed valves also require some maintenance, especially if they’re open. Cleaning out clogged lines, preventing chemical leaks, and repairing holes caused by piping materials contracting during expansion are all things that will reduce efficiency.
In general, keeping your pipes and valves operating efficiently is something you should put priority 1 on.
Patch your valves
There are two types of ball joints, wear them for different lengths of time
First is the friction type that uses abrasion to break down the lubrication between balls and sockets evenly. After some use, you may need to replace both joints.
Second is the glue type made from either polymer or metal glues that stick when inserted into holes with pressure. These can be changed out more frequently but because they’re less prone to failure, fewer will fail per unit time.
Both have advantages as well as disadvantages. When choosing which one is right for you, consider cost, amount of downtime for repairs, and reliability.
If repairability is important to you, know that all valve joint replacements are also repeatable if done correctly.
There are many examples in history where lack of familiarity with these details has caused profound failures. A small investment at this stage could save headaches later.
Know the different valve types
There are many different ways to connect valves together, which is why there are so many varieties of basic plumbing systems. The type of valve you need depends how you want to use it.