Advantages and disadvantages of ductile iron pipe fittings and installation specification

1、 Advantages and disadvantages of ductile iron pipe fittings: advantages: in medium and low pressure pipe network, ductile iron pipe has safe and reliable operation, low damage rate, convenient and fast construction and maintenance, excellent anti-corrosion performance, etc.

Disadvantages: in high-pressure pipe network, generally not used, low pressure resistance. Because the pipe body is relatively bulky, the installation must use machinery. In case of water leakage after pressure test, all pipes must be dug out, lifted to the height where they can be put into the clamp, and the clamp shall be installed to prevent water leakage.

2、 Installation specification of ductile iron pipe: the appearance of ductile iron pipe provides a new type of pipe with excellent performance for water supply in China. In order to better apply ductile iron pipe in engineering, designers and constructors should be familiar with the characteristics of ductile iron pipe, constantly find problems and solve them, so as to make the design more reasonable and the construction more standardized, and make the new pipe play a greater role in water supply engineering.

The three-way Haff joint leak stopper is specially used for the quick repair of the pipeline three-way joint or the three-way itself in case of water leakage. The main tee can be used to repair the main tee of various materials, such as N25 flange ductile iron pipe, cast iron pipe, iron pipe, galvanized pipe, steel pipe, e pipe, VC pipe, etc. In this paper, a new type of three-way huff joint plugging device is introduced, which can solve the problems of sand hole, leakage and fracture of three-way pipes made of various materials. The structure of the three-way plugging device adopts the upper and lower structure, with natural rubber sealing pad inside. When using, it is aligned with the three-way part of the pipeline, and the bolts can be tightened. It is the first X "good medicine" in the rush repair of pipeline tee fittings.

In addition, for variable diameter tee, variable diameter tee plugging device can be customized. For corrosive tee of pipeline medium, stainless steel tee plugging device and sealing fluororubber can be customized. No matter for water pipe, steam pipe or chemical pipe, the direct use of tee plugging device has more advantages than the replacement of tee itself.

Haff joint leak stopper, also known as tee repair device, is an emergency repair device with cast iron shell and rubber lining. It is mainly used to repair the leakage of tee joint or tee itself. The Haff joint of tee joint is easy to install. When the tee joint leaks, it does not need to stop the water supply. The original tee pipe fittings can be directly wrapped with the Haff joint of tee joint to achieve the effect of leak arrest.

Types of ductile iron pipe fittings: K-type ductile iron pipe fittings, T-type ductile iron pipe fittings.

Ductile iron pipe connection: flange, socket, socket

Pressure bearing standard of ductile iron pipe fittings: N10, n16, N25

Metallographic structure of ductile iron pipe: a certain amount of spherical graphite is distributed on the ferrite and pearlite matrix. According to the requirements of nominal diameter and elongation, the proportion of ferrite and pearlite in the matrix is different. The proportion of pearlite with small diameter is generally less than 20%, and that with large diameter is generally controlled at about 25%.

Anti corrosion treatment of ductile iron pipe fittings:

1. Asphalt paint coating

Asphalt coating is used for gas pipeline. Preheating the pipe before spraying can improve the adhesion of asphalt paint and accelerate the drying.

2. Cement mortar lining + special coating

This kind of internal anti-corrosion measures is suitable for the pipeline conveying sewage, and can improve the anti-corrosion ability of the lining.

3. Coal tar epoxy coating

Epoxy coal tar pitch coating is suitable for both gas pipeline and sewage pipeline. It is a two-component coating with high adhesion and very smooth surface.