How to ensure the quality of stainless steel joints during construction?

From the construction process, we found that the quality of pipe fittings arrived mainly has the following problems:

How to ensure the quality of stainless steel joints during construction?

Uneven wall thickness of pipe fittings

The uneven wall thickness of pipe fittings mainly occurs in the parts with the largest deformation of pipe fittings.Standard stainless steel joint manufacturers such as elbow back wall thinner than other parts;The wall thickness of the pipe orifice is different from that of the fitting body.The state provides in concerned standard.The maximum wall thickness reduction of the tube-fitting jiangsu buckle joint should not exceed 1, 2, 5 of its nominal thickness, but it was found in field measurement that some wall thickness reduction reached 2o ~ 30.For the inspection of such problems, the general caliper and other measuring tools are often difficult to find, the standard stainless steel joint can only be measured by the use of ultrasonic thickness gauge.

Second, hardness exceeds standard

The problem of hardness exceeding the standard is mainly caused by the heat treatment process after forming.This problem is generally solvable

The material and the defects of the pipe joint of the shandong type in the process of processing

Such problems are the most harmful to the safety of the device.And it's a lot of trouble to check.There are many and complex factors causing defects in the standard stainless steel quick insert joint.So why do they pose a safety hazard and how can such problems be avoided?Now three as an example to do one by one analysis.

For this type of steel pipe, the steel mill shall conduct hydrostatic test one by one.For large and medium-sized steel, eddy current or ultrasonic crossing inspection (uT) is often used instead of hydraulic inspection. If the inspection is strictly in accordance with the national and relevant standards, the quality of the pipe can be guaranteed.But sometimes it is inevitable that there will be missed inspection, false inspection, more henan hydraulic transition joint even due to the pipe procurement channels mixed, some of the raw materials have not been tested into the circulation field, therefore, for the arrival of the pipe is especially non-batch directly purchased from the steel pipe factory materials.In addition to comprehensive reinspection according to the standards, the rate of reinspection should be increased, even root by root.From our contact with several has wide scale of pipe fittings manufacturing survey, many manufacturers to purchase pipes of lax, blindly believe in materials of the factory quality certificate (it is important to note that some of the factory quality certificate of authenticity is a problem), but only the appearance of the double block pipe inspection made of these unqualified pipe fitting, its quality is difficult to guarantee.In addition, the inspection methods of many manufacturers are neither advanced nor perfect, so some unqualified pipe fittings are easy to leave the factory as qualified products.