Key points of gate valve installation 

According to different classification methods, gate valves can be divided into parallel gate valve, wedge gate valve, non-rising stem gate valve, rising stem gate valve, knife gate valve etc.

1) The installation position, height, inlet and outlet direction must meet the design requirements, and the connection should be firm and tight.

2) The handle of all kinds of manual valves installed on the insulation pipeline shall not be downward.

3) The appearance inspection must be carried out before the valve is installed, and the valve name plate shall comply with the current national standard "general valve mark" gb12220. For the valve with working pressure greater than 1.0MPa and cutting off function on the main pipe, the strength and tightness test shall be conducted before installation, and the valve can only be used after it is qualified. During the strength test, the test pressure shall be 1.5 times of the nominal pressure, the duration shall not be less than 5min, and the valve shell and packing shall be qualified if there is no leakage. In the tightness test, the test pressure is 1.1 times of the nominal pressure; The duration of the test pressure shall meet the requirements of GB 50243, and the valve disc sealing surface shall be qualified if there is no leakage.

Installation procedure

1. According to the design installation elevation, mark the vertical center line of the water outlet and the elevation line of the bottom of the gate valve on the wall surface of the water outlet, and the deviation shall not be greater than ± At the same time, check whether the center of the lifting hole of the gate body is aligned with the reserved support hole of the hoist;

2. The gate valve shall be hoisted in place and firmly erected;

3. Lift the gate valve and stick it to the wall in place, adjust the levelness and perpendicularity of the gate body (the levelness and perpendicularity of the bottom groove and side groove of the gate frame are not more than 1 / 1000), connect the gate valve frame with the embedded steel plate reliably, and take effective sealing measures for secondary pouring to ensure no leakage between the gate valve frame and the structure.

4. Install the thrust screw and hoist base of gate valve. The installation levelness and verticality shall meet the design requirements. The hoist center and the screw hole center of gate valve plate shall be located on the same vertical line. The verticality deviation shall not be greater than 1 / 1000, and the deviation in the whole process shall be less than 2mm. Connect the thrust screw of gate valve. Take the gate end of the thrust screw plate as the benchmark, adjust the thrust screw of gate valve vertically and fix the hoist base, The hoist base shall be padded with iron pad. Then, the secondary concrete pouring of gate valve and hoist is carried out.

5. Inspection:

① After the gate valve is installed, check that the installation accuracy meets the installation requirements, and all fasteners are firmly connected; Check and fill the grease in the hoist;

② The opening and closing test of gate valve is carried out under the condition of no water. The operation is flexible, the action is in place, the screw rotates smoothly, and the door plate has no clamping, sudden jump and abnormal sound;

③ Under the designed water level, the gate valve can be opened and closed freely without sudden jump, and the limit device should be sensitive, accurate and reliable;

④ Assist the supplier to carry out on-site leakage test according to relevant regulations. Under the condition of maximum design water level, the leakage of gate valve meets the requirements.

Pay attention to the installation direction of the gate valve must be vertical to the ground, and the special gate valve shall be installed according to the instructions.