What are the requirements for valve installation?

    Valves are pipeline accessories used to open and close pipelines, control flow direction, regulate and control the parameters of transport media (temperature, pressure and flow). According to its function, it can be divided into shut-off valve, check valve, control valve, etc.

    Valve is the control part of the fluid transportation system. It has the functions of cut-off, regulation, diversion, countercurrent prevention, stabilization, diversion or overflow relief. Valves used in fluid control systems range from the simplest cut-off valves to various valves used in extremely complex automatic control systems. What are the specific requirements for valve installation?

Installation requirements

1. Before installing the valve, check carefully whether the type and specification of the valve used are in conformity with the design.

2. Check and check whether the valve can be used under the required conditions according to the type of the valve and the manufacturer's instructions.

3. When the valve is hoisted, the rope should be tied to the flange connection between the valve body and the valve cover, and not tied to the handwheel or stem, so as to avoid damaging the stem and the handwheel.

4. When installing valves in horizontal pipelines, the valve stem should be vertical upward, and downward installation of the valve stem should not be allowed.

5. When installing valves, the forced counterpart connection mode of pulling hard and drawing hard shall not be adopted, so as to avoid damage due to uneven force.

6. Open-stem gate valve should not be installed in underground damp place to avoid stem corrosion.

Sealing requirements

The sealing performance of the valve refers to the ability of the sealing parts of the valve to prevent medium leakage. It is the most important technical performance index of the valve. There are three sealing parts of the valve: the contact between the opening and closing parts and the two sealing surfaces of the valve seat; the fit between the filler and the stem and packing box; and the connection between the valve body and the cover. The former leakage is called internal leakage, which is commonly referred to as lax closure, and it will affect the ability of the valve to cut off the medium. Internal leakage is not allowed for truncation valves. Leakage at the last two places is called leakage, i.e. medium leaks from inside to outside of the valve. Leakage can cause material loss, pollution of the environment, and serious accidents. For flammable, explosive, toxic or radioactive media, leakage is not allowed, so the valve must have reliable sealing performance.

Valve Specification Requirements

1. Valve type should indicate the requirement of national standard number. If it is an enterprise standard, the relevant description of the model should be indicated.

2. The working pressure of the valve should be greater than or equal to the working pressure of the pipeline. Without affecting the price, the working pressure that the valve can bear should be greater than the actual working pressure of the pipeline.

3. Valve manufacturing standards shall specify the national standard number according to which they are manufactured. If they are enterprise standards, enterprise documents shall be attached to the procurement contract.