Xi'an Longjoy Foreign Trade Co.,Ltd quality control

Process Flow

The production process of pipe fittings mainly includes forming, heat treatment, bevelling, surface treatment, non-destructive testing, marking, packing.

Different pipe fittings have different forming methods.

Seamless pipe fittings are pipe cutting. The process flow is cutting, bulge-forming, end-cutting, heat treatment, bevelling, surface treatment, non-destructive testing, marking, packing.

Welded pipe fittings are plate cutting. The process flow is cutting, press-forming, trimming, welding, bevelling, surface treatment, non-destructive testing, marking, packing.

Ductile cast iron pipe fittings are casting. The process flow is pre-expand beads, model shaping, bond&model form, coat painting, model lay box, molten iron melting, nodular treatment, pouring, polish&clean, zinc paint spray, mechanical machining, hydraulic press test, cement lining, bituminous paint externally, finished products packing. 

Quality Control

Quality inspection includes non-destructive test, hydraulic test, tensile test, hardness test, dimensions check, supersonic wave thickness measure, lining thickness measure, coat thickness measure.

The pipe and plate used for the pipe fittings should be selected according to the material characteristics and the shape of the blank used in the product. The shape, size, and other requirements of the blank are based on the process regulations of different products.

Inspection of heat treatment is generally done through hardness tests.

Non-destructive testing of pipe fittings in accordance with order requirements or clear provisions of standards.