1) Considered from the sealing performance, the sealing performance of the ball valve is better than the butterfly valve, the ball valve is two-way zero leakage. Butterfly valve is bi-directional ANSI V standard (no visual leakage). So both are sufficient to meet the heating pipe network requirements, the normal maintenance and repair of the pipe network will not be affected. 2) From the perspective of flow capacity, ball valve flow capacity is superior to the butterfly valve, because the butterfly valve in the open state of the valve plate and the valve shaft occupies part of the flow channel, the smaller the diameter they occupy the greater the proportion of the flow channel. 3) From the point of view of volume and weight, it is easy to install, the valve ball valve below DN300 is better, the valve butterfly valve above DN300 is lighter and smaller. 4) From the operating torque, because the butterfly valve is a three eccentric metal sealing butterfly valve, so the butterfly valve opening and closing torque is very small, and the ball valve with the increase of the diameter of the contact area of ​​the sealing surface also increases with the square, random Large-diameter ball valve opening and closing torque can be very large. 5) From the service temperature, the ball valve is not suitable for steam media because of the sealing material and the structure, and the butterfly valve can be used for the conventional saturated steam medium for heating (below 350 ° C). 6) From the standpoint of pipe network stress, the valve can withstand higher stress due to the valve structure. 7) From the service life, the ball valve and butterfly valve can achieve a longer service life (normal use for more than 15 years), but the ball valve seal structure plays an important role in non-metallic, but the butterfly valve is pure metal to metal seal, So under normal circumstances the life of the butterfly valve will be longer. 8) From the price point of view, DN250 (including) the following ball valve prices will be better, more than DN300 butterfly valve prices will be more advantages. In summary, in the central heating network in general, DN300 below the ball diameter of the valve is better, more than DN300 caliber butterfly valve cost better. This is also the choice of many years of experience for most designs and users.