SU887198A1 - Method of applying protective layer on head pipe metallic core - Google Patents

Description

one

The invention relates to the field of production of reinforced concrete pipes, and more specifically to methods of applying a protective layer on the metal core of the standpipe.

There is a known method of applying a protective coating on rotation bodies, preferably on the cores of centrifuged tubes, by gunning a concrete mix layer at a speed of 30-40 m / s and subsequent heat treatment 1.

The disadvantage of this method is the low quality of the molded articles associated with the detachment of the protective layer from the core.

The closest technical solution known is the method of applying a protective layer on the metal core of the pressure pipe, which includes wetting its surfaces and then applying the concrete mix 2.

The disadvantages of this method are the increased cost of manufacturing products and their low quality.

The purpose of the invention is to improve the quality of the molded products and the cost of their manufacture.

This goal is achieved by the fact that, in the method of applying a protective layer on the metal core of the Shut-off pipe, I include wetting its surfaces

followed by sanding concrete with concrete, wetting the surfaces of the metal core with a saturated aqueous solution of neutral superphosphate at 50-80 ° C.

The way the protective layer is applied onto the metal core of the pressure pipe is as follows. The prepared metal heart is applied to the surface by centrifuging and gunning the concrete mixture onto its surface by wetting its surfaces with a saturated solution of neutral superphosphate in water

15 at 50-80 ° C.

Example 1. Take a solution of neutral superphosphate in a ratio of 100 weight. including water 3 wt. including superphosphate at 50 ° C and moisten them with the surface of the prepared

20 metaclic core. After drying the surfaces of the metal core, a thin layer of neutral superphosphate is formed. This surface layer is applied first by centrifugation, and

25 then by gunning the concrete mixture onto the inner and outer surfaces of the core. Then the molded pipe is subjected to heat treatment.

Example 2. A neutral superphosphate solution is taken at 70 ° C in cooTHOuiennn

100 weight. hours of water to 18 wt. including superphosphate and moisten them with the surface of the prepared metal core.

After drying, a thin layer of neutral superphosphate is formed on the surfaces of the metal core. This surface layer is applied first by centrifuging and then by gunning a concrete mix of a given layer for the internal and external coating, respectively. After that, the manufactured pipe is subjected to heat treatment according to a known technology.

Due to the surface treatment of the metal core with a solution of neutral superphosphate in water, the quality of products is greatly improved by increasing the adhesiveness of the core surfaces and thereby completely eliminating the possibility of peeling off the protective layers and reducing the cost of manufacturing products by simplifying the surface treatment process, reducing

labor costs and the cost of protective coatings. This also makes it possible to significantly increase productivity.

Claims (2)

Invention Formula The method of applying a protective layer to the metal core of the pressure pipe, which includes wetting its surfaces and then applying a concrete mix, characterized in that, in order to increase the quality of the molded products and reduce their production cost, the surfaces of the metal core are watered with a saturated aqueous solution of neutral superphosphate at 50 -80 ° C. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 531743, cl. B 28B 21/44, 1975. 2. USSR author's certificate No. 605717, cl. B 28B 21/44, 1976.