Can the galvanized pipe of the outdoor pipe network of the fire pipe be welded?

Zinc steel pipe, divided into hot-dip galvanizing and electro-galvanizing, hot-dip galvanized thick, with uniform coating, strong adhesion, long service life and other advantages. The cost of electro-galvanizing is low, the surface is not very smooth, and its own corrosion resistance is much worse than that of hot-dip galvanized pipes.

Strictly speaking, it cannot be welded.

GB50242-2002 "Code for Construction Quality Acceptance of Building Water Supply, Drainage and Heating Engineering" is stipulated as such.

Galvanized steel pipes with a pipe diameter of less than or equal to 100mm should be connected by threads, and the surface of the galvanized layer and the exposed threaded part damaged during the threading should be treated with anti-corrosion; Galvanized steel pipes with a pipe diameter of more than 100mm should be connected by flanges or ferrule special pipe fittings, and the welds between galvanized steel pipes and flanges should be galvanized twice.

The welding of galvanized pipes is not good for the human body and the anti-corrosion quality of the pipes. If the larger galvanized pipe (if it is greater than DN100), it can be connected by grooves, or flanged connection, and installed twice, regardless of the fire protection system or water supply and return system. Of course, the use of zinc spraying treatment is a deceptive method, which is a method often adopted on the construction site.

According to the specification, it is not allowed to be welded, it must be connected with a thread, and the leaking part of the pipeline should be pressed after completion, and finally 3 oil and 2 felt anti-corrosion treatment needs to be done; If it is your own drawing, the welder's technology must be good, and the leakage part of the pipeline should be pressed after completion, and 3 oil and 2 felt anti-corrosion treatment should be done after completion.

Galvanized pipes cannot be connected by welding. The high temperature generated by electric welding will destroy the galvanized layer of the inner wall of the pipe, and the inner wall cannot be galvanized twice.

The specification stipulates that galvanized steel pipes shall not be welded, and welding is allowed when welding is not necessary, but anti-corrosion treatment shall be carried out immediately after welding.

Welding can be done, but it must be treated with anti-corrosion. Generally, the outdoor pipeline is relatively large, and it is best to use welded steel pipes outdoors, and do pressure testing after welding, and then do a good job of anti-corrosion treatment.

Yes, but it's better to use silk splicing.

It can be welded, but not directly, it needs to pass through the flange.

Hello, there is no mandatory requirement that the cost of fire hydrant welding and trench connection engineering with guessing mold is about the same (welding people are expensive; Groove pipe fittings are expensive), but the groove connection is not like welding, so that the construction site can reduce the fire source point, and can better achieve fire prevention measures, so now the design institute in this area is generally designed to be groove connection, and there is a slow point that the groove connection can be shorter than the welding construction period.

Summary. The connection methods of fire galvanized pipes below DN100 include threaded thread connection and groove connection, flange and compression connection.

According to the requirements of GB50974-2014 specification, the connection of overhead pipelines should be grooved connectors (clamps), threads, flanges, clamping, etc., and welding connections should not be used.

When the pipe diameter is less than or equal to DN50, it should be connected by thread and press, when the pipe diameter is greater than DN50, it should be connected by groove connectors and flanges, and when the installation space is small, groove connectors should be used.

What is the connection method for fire galvanized pipe below DN100.

Hello This is a very good question, I need a little time to answer, please be patient.

The connection methods below DN100 for anti-hand tremor and anti-galvanized pipes include threaded and grooved connections, flanges and compression connections. According to the requirements of GB50974-2014 specification, the connection of overhead pipelines should be made of groove connectors (clamps), threads, flanges, clamping, etc., and welded connections should be used for non-world banquets. When the pipe diameter is less than or equal to DN50, it should be connected by thread and press, when the pipe diameter is greater than DN50, it should be connected by groove connectors and flanges, and when the installation space is small, groove connectors should be used.

What kind of connector is used to connect galvanized DN100 for sewage treatment?

Flange connection method or direct welding.