Casting Train Valve Body Branch Pipe Tee

Train valve body branch pipe tee

Function

• Connecting pipelines: It is used to connect different pipelines in the train braking system, such as the main brake pipe, the brake system pipeline, and the automatic derailment valve pipeline, so that compressed air can be reasonably distributed and flow between the pipelines.
• Controlling air flow direction and flow rate: Through the control of the valve core of the three – way valve, the flow direction of compressed air can be changed, and the connection or disconnection between pipelines under different working conditions can be realized to meet the needs of different operations such as train braking and relief.

Structural characteristics

• Valve body: It is usually made of high – strength metal materials, such as cast steel, to withstand the pressure of compressed air in the braking system and the vibration during train operation. The valve body has three interfaces, which are connected to different pipelines respectively, and its shape is generally T – shaped or Y – shaped.
• Valve core: It is located inside the valve body and is a key component for controlling the direction and flow rate of air flow. The valve core can rotate or move in the valve body through manual operation or electric control, so as to realize the connection or cut – off between different interfaces.
• Valve seat: It is located between the outlet and the bypass port of the valve body and plays a role in preventing fluid from passing through. When the valve core is closed, it fits closely with the valve seat to prevent compressed air leakage.

Working principle

• Inflation and relief position: When the pressure of the train pipe rises, the three – way valve is in the inflation and relief position. The pressure air of the train pipe enters the upper part of the main piston through the mounting hole, pushing the main piston downward, so that the train pipe charges the working air cylinder, and at the same time, the acting air cylinder exhausts and relieves, realizing the relief state of the train.
• Service braking position: When the train pipe decompresses at a rate exceeding that of service braking, a pressure difference is generated on both sides of the main piston, and the main piston rod moves upward, driving the sliding sleeve to continue moving upward against the frictional resistance to reach the braking position, forming a passage for the working air cylinder to charge the acting air cylinder, thus generating the braking effect.
• Braking pressure maintaining position: After the train pipe stops decompressing, initially, the working air cylinder is still charging the acting air cylinder. When the pressure of the train pipe and the working air cylinder on both sides of the main piston is close, under the reaction force of the stabilizing spring at the tail of the main piston and the self – weight of the main piston, the main piston moves downward, cutting off the passage between the working air cylinder and the acting air cylinder, and the pressure of the working air cylinder and the acting air cylinder is maintained. At this time, the three – way valve is in the pressure maintaining position, keeping the train in the braking state.