How to ensure the installation quality of stainless steel ventilation pipes in fire fighting engineering?

In order to ensure the installation quality of stainless steel ventilation pipes in fire fighting engineering, we can start with the preparation before construction, pipeline processing, pipeline installation, system debugging and testing, and the specific measures are as follows:

Preparation before construction

Material inspection: strictly inspect the stainless steel ventilation pipes and related accessories entering the site. Check the material certificate, quality certificate and other documents of pipes to ensure that they meet the design requirements and relevant standards. Observe whether the surface of the pipe is smooth, whether there are cracks, sand holes, air holes and other defects, and measure the thickness, diameter and other dimensions of the pipe to ensure that the deviation is within the allowable range.

Review of construction drawings: Organize constructors and technicians to carefully review the construction drawings, get familiar with the details such as pipeline layout, direction, connection mode and slope requirements in the drawings, and make clear the installation positions and technical requirements of each component. Communicate and coordinate with the design unit in time for problems or questions existing in the drawings to ensure the accuracy and integrity of the construction drawings.

Construction scheme formulation: according to the engineering characteristics and construction drawings, formulate a detailed construction scheme. The scheme shall include the construction process, construction methods, quality control measures and safety guarantee measures. Technical disclosure shall be made to the construction personnel to make them understand the construction tasks, quality standards and operation points.

Pipeline processing

Cutting and beveling: use appropriate cutting tools, such as plasma cutting machine and stainless steel special cutting saw, to ensure that the cutting surface is flat and smooth, without burrs and notches. For pipes that need to be welded, groove processing shall be carried out according to the requirements of welding process, so as to ensure that the groove angle and blunt edge size meet the requirements and ensure the welding quality.

Bending and forming: In the process of pipe bending and forming, professional pipe bending equipment and dies are used to control the bending radius and angle to avoid defects such as wrinkles and cracks in the pipe. For large-diameter pipelines or pipelines with special shapes, customized molds can be used for processing to ensure the shape and dimensional accuracy of pipelines.

Welding quality control: Welding personnel must have corresponding qualifications and welding experience, and operate in strict accordance with the welding procedure. Select appropriate welding materials and welding methods, such as argon arc welding and carbon dioxide gas shielded welding. Before welding, clean the groove and both sides of the pipeline to remove impurities such as oil stain and rust. During the welding process, the welding current, voltage, welding speed and other parameters are controlled to ensure that the weld is well formed without defects such as porosity, slag inclusion and incomplete penetration. After welding is completed, visual inspection and nondestructive testing, such as X-ray inspection and ultrasonic inspection, shall be carried out on the weld to ensure that the weld quality meets the standard requirements.

piping erection

Installation of supports and hangers: Set supports and hangers reasonably according to the weight, size and installation position of the pipeline. The spacing between supports and hangers shall meet the design and specification requirements, and the installation shall be firm and reliable, and shall be in close contact with the pipeline without looseness. The installation position of support and hanger should avoid the weld and connection parts of the pipeline to prevent damage to the pipeline.

Pipe connection: The connection methods of stainless steel ventilation pipes include flange connection, welding connection and clamp connection. When flange connection is adopted, ensure that the flange surface is flat, the bolt hole position is accurate, the bolt tightening force is even, and the flange gasket should be made of suitable materials and specifications to ensure good sealing performance. When welding connection is adopted, in addition to ensuring the welding quality, attention should also be paid to the clearance and misalignment of the pipeline to ensure the coaxiality and straightness of the pipeline after connection. When the clamp is connected, the clamp should be installed firmly, and the rubber sealing ring between the clamp and the pipeline should be installed in place, and there should be no distortion or deformation.

Slope and verticality of pipeline: control the slope and verticality of pipeline according to the design requirements. In the installation process, use tools such as level and plumb line to measure and adjust, so as to ensure that the pipeline slope is even, the drainage is smooth, and there is no slope reversal phenomenon. The verticality deviation of the pipeline should be within the allowable range to ensure the installation quality and neat appearance of the pipeline.

Treatment of passing through walls and floors: When pipelines pass through walls or floors, sleeves shall be set. The inner diameter of the casing should be 20-40mm larger than the outer diameter of the pipeline, and incombustible materials should be used for sealing between the casing and the pipeline, such as fireproof rock wool and fireproof sealant, so as to ensure the integrity of fireproof separation.

System debugging and testing

Air leakage test: After the installation is completed, air leakage test shall be conducted for the ventilation pipeline system. The positive pressure method or negative pressure method can be used to measure the air leakage of pipeline system under the specified pressure. If the air leakage exceeds the allowable value, the air leakage point should be found and repaired until it meets the requirements.

Ventilation performance debugging: start the ventilation system, adjust the speed of the fan and the opening of the valve, so that the parameters such as ventilation and wind speed can meet the design requirements. Measure and adjust the air volume of each tuyere to ensure the uniform distribution of air volume and meet the ventilation requirements of fire fighting projects.

Fire linkage test: Conduct linkage test with other equipment of fire protection system, such as fire alarm system, fire damper and smoke exhaust valve. When a fire breaks out, the ventilation piping system should be able to start the corresponding fans and valves in time according to the design requirements, realize the functions of smoke exhaust and air supply, and ensure the reliability of the overall performance of the fire fighting system.