Elite Piping Manufacture takes the installation feedback from blind flange customers seriously.
Blind flange is one of the main products of Elite Piping Manufacture, and our company attaches great importance to after-sales service of blind flange.
After receiving the blind flange, the customer will install the blind flange and provide us with relevant feedback in a timely manner after the installation is completed, and we will provide corresponding solutions in a timely manner.
Installation Feedback From Blind Flange Customers Are As Follows
- After the flange and the pipe are welded, the flange end face is not perpendicular to the axis of the pipe.
Hazardous
Affecting the visual quality, the entire pipeline is not straight after the two flanges are connected; the flange surface connection is not tight, resulting in media leakage.
Our Corresponding Solutions To The Installation Feedback From Blind Flange Customers
The flange end face should be perpendicular to the center line of the pipeline. The deviation value can be checked using a square ruler and a steel ruler. When the nominal diameter of the pipe is less than or equal to 300mm, the allowable deviation value is 1mm; when the nominal diameter of the pipe is greater than 300mm, the allowable deviation value is 2mm.
After the flanges are tightened, the bolt holes of the two flanges are misaligned, the outer edges of the flanges are misaligned, and the axes of the two flanges are not axial.
Hazardous
1) Bolt misalignment
- The screw holes are misaligned and bolts with small diameters are used to tighten them. The connection strength is low and it is easy to cause leakage at the flange joint surface;
- Severe misalignment will make it difficult for the bolts to pass through and cause rework.
2) Flange misalignment
- The flange surface is not well combined, which may lead to leakage;
- The two flanges are not axial, which reduces the flow cross-section, increases the medium flow resistance, and affects the flow rate.
Our Corresponding Solutions To The Installation Feedback From Blind Flange Customers
The flange connection should maintain the same axis, the center deviation of the screw hole should not exceed 5% of the hole diameter, and the bolts should be ensured to penetrate freely.
There are obvious signs of damage on the sealing surface of the blind flange.
Hazardous
1) The flange is excessively damaged, causing the flange to be scrapped and increasing construction costs. For example, special flanges may also affect the construction period;
2) Reduce the effective sealing width of the flange, reduce the flange sealing performance, and cause flange leakage.
Our Corresponding Solutions To The Installation Feedback From Blind Flange Customers
The flange should be visually inspected before installation and should meet the following requirements:
- The nominal pressure of the flange should meet the design requirements.
- The flange sealing surface should be smooth and smooth, without burrs and radial grooves. The threaded part of the flange should be intact and without damage. The concave and convex surface flanges should fit together naturally, and the height of the convex surface should not be lower than the depth of the groove.
- The threads of bolts and nuts should be complete, without defects such as scratches or burrs; bolts and nuts should fit well and should not be loose or stuck.
- The gasket is not concentric with the flange, the gasket drops obviously, and is not fully in contact with the flange sealing surface.
Hazardous
1) Changes the cross section of the medium and increases the local head loss of the pipeline, which will affect the flow rate and flow rate of the medium;
2) The effective contact area between the gasket and the flange sealing surface is reduced, which reduces the sealing performance and easily causes flange interface leakage.
Our Corresponding Solutions To The Installation Feedback From Blind Flange Customers
The size of the flange gasket should match the flange sealing surface, and the gasket installation should be correct. Using two or more flange gaskets in one sealing surface is strictly prohibited.
Media leakage occurs from the flange sealing surface during pipeline pressure testing or operation.
Hazardous
Flange seal leakage can cause the leakage of conveyed materials, gases and other media, which can cause medium loss and environmental pollution at a mild level, affect the normal operation of the system, and even cause major fires or personal casualties.
Our Corresponding Solutions To The Installation Feedback From Blind Flange Customers
1) If the gasket and flange sealing surface are mechanically damaged, use new gaskets;
2) The sealing material of the gasket should match the properties of the medium,
3) The gasket is installed concentrically with the flange;
4) The two flanges are parallel and the flange bolts are tightened evenly;
The bolt specifications of the fastening flange do not match; the bolt is too long or the bolt is too short and is lower than the nut.
Hazardous
1) The bolts are not exposed, which affects the tightening strength and may cause leakage;
2) The exposed threads are difficult to disassemble due to paint, rust or damage, etc., and often need to be cut during maintenance, which is a huge waste;
3) Exposed threads are meaningless to the strength of the threaded connection, but increase the workload of loading and unloading;
4) The total length of exposed bolts increases, which consumes more steel and increases costs.
Our Corresponding Solutions To The Installation Feedback From Blind Flange Customers
- The diameters of bolts and screw holes should match, and bolts of the same specification should be used. The installation directions should be consistent. The tightening bolts should be symmetrical and even, and the tightening should be moderate. The exposed length of the bolt after tightening should not be greater than 1 times the thread pitch, and should not be shorter than the nut.
- Bolts of the same specifications should be used, the installation direction should be consistent, and the nut tightening should be symmetrical and even; after the nuts are tightened, the exposed threads of the bolts should be 1 to 3 buckles, and should be rust-proofed.
- The prefabricated pipelines were placed randomly on the construction site without effective protection and were in direct contact with the soil. The flange surface was severely corroded.
Hazardous
Severe corrosion has occurred before installation, which will affect the normal service life of the flange; corrosion of the flange sealing surface will affect the flange sealing strength, resulting in media leakage after the pipeline is in operation.
Our Corresponding Solutions To The Installation Feedback From Blind Flange Customers
Prefabricated pipes should be effectively protected and are not allowed to be placed randomly on the construction site to avoid direct contact with soil.
Corrosion pits appear on the flange sealing surface.
Hazardous
Wrong selection of gasket and liner materials will cause corrosion of the stainless steel flange sealing surface, cause water leakage, affect the service life of the flange, and cause other losses.
Our Corresponding Solutions To The Installation Feedback From Blind Flange Customers
Choose the correct flange gasket and liner materials according to the purpose of the flange.
If you have any questions about blind flange installation, please feel free to contact us. Installation feedback from blind flange customers is crucial to the further development of our company.
