A.Gate valve installation
Gate valve, also known as gate valve, is a valve that uses a gate to control the opening and closing, and adjusts the pipeline flow and opens and closes the pipeline by changing the cross section. Gate valves are mostly used for pipelines that fully open or fully close the fluid medium. Gate valve installation generally has no directional requirements, but it cannot be flipped.
B.Installation of globe valve
The globe valve is a valve that uses the valve disc to control the opening and closing. Adjust the medium flow or cut off the medium passage by changing the gap between the valve disc and the valve seat, that is, changing the size of the channel section. When installing the shut-off valve, attention must be paid to the flow direction of the fluid.
The principle that must be followed when installing the globe valve is that the fluid in the pipeline passes through the valve hole from bottom to top, commonly known as “low in and high out”, and it is not allowed to install it backwards.
C.Installation of check valve
Check valve, also known as check valve and one-way valve, is a valve that automatically opens and closes under the action of the pressure difference between the front and rear of the valve. Its function is to make the medium flow in only one direction and prevent the medium from flowing back in the reverse direction. According to their different structures, check valves include lift type, swing type and butterfly wafer type. Lift check valve is divided into horizontal and vertical. When installing the check valve, attention should also be paid to the flow direction of the medium and cannot be installed in reverse.
D.Installation of pressure reducing valve
The pressure reducing valve is a valve that reduces the inlet pressure to a certain required outlet pressure through adjustment, and relies on the energy of the medium itself to automatically keep the outlet pressure stable.
1. The pressure reducing valve group installed vertically is generally set along the wall at a suitable height from the ground; the pressure reducing valve group installed horizontally is generally installed on the permanent operating platform.
2. The application steel is loaded into the wall on the outside of the two control valves (usually used for globe valves) to form a bracket, and the bypass pipe is also stuck on the bracket to level and align.
3. The pressure reducing valve should be installed upright on the horizontal pipeline, and should not be inclined. The arrow on the valve body should point to the direction of medium flow, and should not be installed backwards.
4. Globe valves and high and low pressure pressure gauges should be installed on both sides to observe the pressure changes before and after the valve. The diameter of the pipeline behind the pressure reducing valve should be 2#-3# larger than the inlet pipe diameter before the valve, and a bypass pipe should be installed for maintenance.
5. The pressure equalizing pipe of the membrane pressure reducing valve should be connected to the low pressure pipeline. Low-pressure pipelines should be equipped with safety valves to ensure the safe operation of the system.
6. When used for steam decompression, a drain pipe should be set. For pipeline systems that require a higher degree of purification, a filter should be installed before the pressure reducing valve.
7. After the pressure reducing valve group is installed, the pressure reducing valve and safety valve should be pressure tested, flushed and adjusted according to the design requirements, and the adjusted mark should be made.
8. When flushing the pressure reducing valve, close the inlet valve of the pressure reducer and open the flushing valve for flushing.
E.Installation of traps
The basic function of the steam trap is to discharge the condensed water, air and carbon dioxide gas in the steam system as soon as possible; at the same time, it can automatically prevent the leakage of steam to the greatest extent. There are many types of traps, each with different performance.
1. Shut-off valves (shut-off valves) should be set before and after, and a filter should be set between the trap and the front shut-off valve to prevent dirt in the condensed water from blocking the trap.
2. An inspection pipe should be installed between the steam trap and the rear shut-off valve to check whether the steam trap works normally. If a large amount of steam is emitted when the inspection pipe is opened, it means that the steam trap is broken and needs to be repaired.
3. The purpose of setting the bypass pipe is to discharge a large amount of condensed water during startup and reduce the drainage load of the trap.
4. When the trap is used to drain the condensed water of the heating equipment, it should be installed at the lower part of the heating equipment, so that the condensate pipe is vertically returned to the steam trap to prevent the water from being stored in the heating equipment.
5. The installation location should be as close to the drain point as possible. If the distance is too far, air or steam will accumulate in the slender pipe in front of the trap.
6. When the horizontal pipeline of the steam main pipe is too long, the drainage problem should be considered.
F.Installation of safety valve
The safety valve is a special valve that the opening and closing parts are in a normally closed state under the action of external force. When the pressure of the medium in the equipment or pipeline rises beyond the specified value, it discharges the medium to the outside of the system to prevent the medium pressure in the pipeline or equipment from exceeding the specified value. .
1. Before installation, the product must be carefully inspected to verify whether there is a certificate of conformity and product manual, so as to clarify the constant pressure when leaving the factory.
2. The safety valve should be arranged as close as possible to the platform for inspection and maintenance.
3. The safety valve should be installed vertically, the medium should flow out from bottom to top, and the verticality of the valve stem should be checked.
4. Under normal circumstances, shut-off valves cannot be set before and after the safety valve to ensure safety and reliability.
5. Safety valve pressure relief: when the medium is liquid, it is generally discharged into the pipeline or closed system; when the medium is gas, it is generally discharged to the outdoor atmosphere;
6. The oil and gas medium can generally be discharged into the atmosphere, and the outlet of the safety valve venting pipe should be 3m higher than the highest surrounding structures, but the following conditions should be discharged into a closed system to ensure safety.
7. The diameter of the population pipe should be at least equal to the inlet pipe diameter of the valve; the diameter of the discharge pipe should not be smaller than the outlet diameter of the valve, and the discharge pipe should be led to the outdoors and installed with an elbow, so that the pipe outlet faces a safe area.
8. When the safety valve is installed, when the connection between the safety valve and the equipment and pipeline is opening welding, the opening diameter should be the same as the nominal diameter of the safety valve.
Post time: Jun-10-2022