网络优化资料：

The installation of the specifications and models of the water control valve does not meet the design requirements. For example, the rated pressure of the hydraulic control valve is less than the system test pressure; the gate valve is used when the diameter of the branch pipe is less than or equal to 50 mm; the stop valve is used for dry hot water heating and the vertical pipe; the butterfly valve is used for the suction pipe of the fire water pump.

Result: The normal opening and closing of the valve and the adjustment of resistance and pressure were affected. During the operation of the proportional solenoid valve system, the valve may even be damaged, requiring maintenance.

Countermeasures: Be familiar with the scope of use of various valves, and select valves of specifications and models according to design requirements. The rated pressure of the valve body should meet the requirements of the system test pressure. According to the requirements of the building code: the branch pipe with a diameter less than or equal to 50mm is a cut-off valve, and the branch greater than 50mm is a gate valve. Gate valves should be used for water, heat, and dry control valves, while butterfly valves should not be used for fire pump suction pipes.

The check valve installation method is wrong. For example, the water (steam) flow direction of the shutoff valve or check valve is opposite to the sign, the valve stem is installed downwards, the horizontally installed check valve is installed vertically, and the handle of the rising stem gate valve or butterfly valve has no opening and closing space, and it is dark. The valve stem is not facing the inspection door.

Result: The valve malfunctioned, the switch of the normally open solenoid valve was difficult to check, and the valve stem facing down often caused water leakage.

Method: Strictly install in accordance with the valve installation instructions, leave enough stem extension opening height for the rising stem gate valve, fully consider the rotation space of the butterfly valve handle, and the various valve stems must not be lower than the horizontal position, let alone fall. When installing a hydraulic control valve, it is not only necessary to install an inspection door that meets the requirements of opening and closing the valve, but also to make the valve stem face the inspection door.