Ball valve is a ball as a closing part of the valve, mainly composed of valve body, seat, ball, stem, handle, driven by the valve stem, and around the ball valve axis for rotary movement, in the pipeline is mainly used to cut off, distribution and change the flow direction of the medium.
ATO sells one piece, two pieces, three pieces of stainless steel ball valves, sizes 1 inch, 2 inch and 3 inch, ball valve lightweight, small size, sealing surface and sphere are often in the closed state, is not easy to be washed away by media, widely used in various industries.
The three piece ball valve is composed of a valve body, two valve covers, a ball, a valve stem, a packing gland, a handle, a lock nut and other important parts. The three-piece ball valve media can be used from left to right and right to left, clockwise is closed, and counterclockwise is open.
The 3 piece ball valve and the gate valve are the same type of valve, the difference is that its closing part is a sphere, and the sphere rotates around the center line of the valve body to achieve opening and closing. Ball valves are mainly used to cut off, distribute and change the flow direction of the medium in the pipeline.
The working principle of ball valve is to make the valve unblocked or blocked by rotating the valve stem. The ball valve switch is light, small in size, can be made into a large diameter, reliable sealing, simple structure, convenient maintenance, the sealing surface and the spherical surface are often closed, and are not easily eroded by the medium, and are widely used in various industries.
In the closed position, the ball is pressed against the valve seat by the mechanical pressure of the valve stem. When the handwheel is turned counterclockwise, the valve stem moves in the opposite direction, and its bottom angular flat disengages the ball from the valve seat. The stem continues to lift and interacts with the guide pins in the helical grooves of the stem, causing the ball to begin to rotate without friction. Until it reaches the fully open position, the ball valve stem is lifted to the limit position, and the ball rotates to the fully open position.
To close, turn the handwheel clockwise, the stem begins to drop and the ball leaves the seat and begins to rotate. Continue to rotate the handwheel, the valve stem is acted by the guide pin embedded in the spiral groove on it, so that the valve stem and the ball rotate 90° at the same time. Just before closing, the ball has rotated 90° without making contact with the seat. During the last few turns of the handwheel, the angular flat at the bottom of the valve stem mechanically wedges against the sphere, making it tightly pressed against the valve seat to achieve a complete seal.
Preparation before installation
Start to install the ball valve
nspection of ball valve after installation
Use of ball valve
The valve is only used as a switch, not for adjustment. In particular, it is not allowed to use under the conditions of exceeding the temperature, pressure limits and frequent alternating pressure conditions. Periodic tightening of bolts at high temperatures is allowed to prevent leakage and minimize thermal gradients. Shock loads and high stress concentrations are not allowed at low temperatures.
Regularly add sealing grease and soft packing to keep the equipment in good condition at all times. The valve should always be in the open or closed position and should not be used for adjustment. When it is not driven manually, the valve switch position should be consistent with the control console switch position and instructions to avoid misoperation.
The working principle is different:
The working principle of the one-piece ball valve is the mechanical pressure of the valve stem; the working principle of the two-piece ball valve is to make the valve unblocked or blocked by rotating the valve.
The valve body of the ball valve is different:
The one-piece stainless steel ball valve is a manual valve. The structural design is integral, and the ball is stabilized by a plug, which is convenient for maintenance. The diameter of the ball valve is also small, and the ball is put in from one side of the valve body after the valve seat is screwed in, then press the ball; the two-piece ball valve is fixed by two pieces of the valve body clamped by the ball, the maintenance is relatively complicated, and the tightness of the bolt in the middle is very important.
The closing parts of the ball valve are different:
The closing part of the one-piece ball valve is a sphere, and the ball rotates around the center line of the valve body to open and close a valve; while the two-piece ball valve has no special requirements.
Step 1: Determine the temperature range of the ball valve
Valves are often used for the treatment of hot or cold fluids. It is very important to determine whether the flow rate through the valve of the medium is low or high temperature, and there are different materials such as ceramics, stainless steel, and PVC used in valve production. Each of them is suitable for a specific temperature range.
Step 2: Determine the working pressure of the ball valve
When a high pressure valve closes, you want to determine how much pressure is in the range in order to select the correct valve size to handle that pressure.
Step 3: Determine what medium is passing through the ball valve
Specific applications and fluid control systems are designed to handle different types of media. Some valves are used against dams and reservoirs. Also used for normal flow of chemicals. There are also special designs for radioactive substances to ensure that the valve does not leak radiation. It is also important to ensure that the fluid passing through the valve is corrosive. These are helpful for the selection of valve body material. This step is also used to ensure the safety of the staff at the valve.
Step 4: Determine the volume of fluid passing through the ball valve
Different flow valves are designed for different purposes, too small or too thick are not suitable, because the correct choice of valve size in order to know the volume of fluid is very important.