Ball Model: YQ44F outlined in previous coke oven coking plant ammonia injection high-pressure high and low pressure circulation system conversion system widely used L-type ball valve of conventional construction, since the parts of the special working conditions, L-type three-way valve in the installation and operation months or even a few days to a leak, the system pressure is reduced, the high-pressure ammonia leak inside the suction band pulverized coal to coke oven collecting pipe, causing severe coking chamber vacuum, it will affect coke quality, and the impact of tight furnace sex. As the valve is installed at the top of the coke oven, the site of high temperatures, poor working conditions, to replace the valve has brought great difficulties. Frequent replacement of the valve, but also to the plant caused great economic losses, and also seriously polluted the environment. In order to solve the above problems we have designed YQ44F-40 DN25 type modular structure of the three-way valve shown in FIG. It is a combination of straight-floating ball valve and check valve sleeve from the left side of the ball valve high pressure system connected to the right side of the check valve connected to the low pressure system, intermediate outlet connected to the discharge line, when the valve is closed, the high-pressure channel cut only return valve flap open automatically driven by the low pressure medium, low ammonia discharged from the middle of the outlet channel. When the valve is turned on, the high-pressure ammonia valve seat to the valve, the check valve is closed, the low-pressure passage is cut off, the high-pressure ammonia discharged from the middle of the outlet channel. After injection is complete, close the ball valve, check valve automatically opens, low pressure ammonia can automatically discharge. Therefore, as long as the operation of a conventional ball valve, as the valve stem for 90 ℃ switch, that can complete high and low voltage switch. Combined three-way valve main features are as follows: 1, due to the combined three-way valve in the straight-floating ball only from the high-pressure side of the system on and off action, and not from the three-way switching function, so even if the ball seat After a period of use disappear assembly preload gap occurs between the ball and valve seat, when the valve is closed, the pressure of the high-pressure side of the medium can still move the ball to the exit side of the seat, so that between the ball and the outlet side of the valve seat close contact, so the valve still has a good sealing performance, modular three-way valve completely solve the traditional L-Way ball easily seal failure. The low-pressure side check valve made of stainless steel, unique design, sensitive, reliable sealing for a long service life. 2, the combined length of the structure and size of the three-way valve is connected with the traditional L-Way ball the same, easy to replace the valve. 3, simple modular three-way valve operation is identical to the traditional L-shaped three-way valve. 4, the overall body structure design, can more effectively prevent the leakage of the valve, the valve of the overall design more perfect.