RU2138340C1 - Method of painting inner surfaces of pipes - Google Patents

Abstract

FIELD: application coats to inner surfaces of pipes and tubular articles; flying vehicles; food-processing; chemical and medical industries. SUBSTANCE: material of coat is pumped in either direction definite number of times by means of compressed air. EFFECT: enhanced reliability and economical efficiency. 1 dwg

Description

 The invention relates to methods for coating products and can be used in a wide range from coating the internal surfaces of pipes in the manufacture of tubular structures, for example, aircraft, to coating with chemically resistant pipe materials in plants of the food, chemical and medical industries.

 A known method of painting the surfaces of nodes by dipping into the coating material. In this method, the surface to be coated may have unpainted spots due to the formation of air bubbles and air sacs (EP patent application N 0 381 082, MKI B 05 D 1/18, 08.08.90).

 If it is necessary to cover only the inner surfaces, it is necessary to clean the outer surface of the products from the coating. This causes additional labor costs and uneconomical use of the coating material.

 The invention is directed to the application of a known method of polishing the inner surfaces of pipes by a circulating fluid treatment method, the use of which would create a reliable and cost-effective coating (copyright certificate SU 116 040, MKI F 28 G 1/16, 08.02.58).

 The essence of the method consists in pumping the coating material through the processed pipe from one cylinder to another using compressed air.

 The proposed method for painting the inner surfaces of pipes differs from the known method of polishing with a new purpose - for painting surfaces, and therefore with a new working fluid.

 A schematic diagram of the installation is shown in the drawing.

 The installation contains cylinders 1 and 2 connected by the pipe 3 to be painted using pneumatic clamps 4 and 5 mounted on taps 6 and 7. Cranes 6 and 7 are located at the ends of pipelines 8 and 9, docked to the lower parts of cylinders 1 and 2.

 The cylinders 1 and 2 in the upper parts are connected with each other and with the compressed air line 10 through pipes 11 and 12 and a two-way valve 13. Between the pipe 12 and the valve 13 a flexible sleeve 14 is installed.

 A two-way valve 13, alternately supplying compressed air to each of the cylinders 1 or 2, is equipped with a pipe 15 for drainage of air from the cylinders.

 Tubes 16 are installed inside the cylinders, having upper holes 17 and lower 18. Each of the cylinders is equipped with a filler neck 19 with a stopper.

 The installation provides heating 20 pipes 3.

 The installation is as follows.

 Compressed air along the line 10 through a two-way valve 13 is fed into the tube 16 of the cylinder 1. From the tube 16, air through the hole 17 enters the free part of the cylinder above the level of the working fluid, previously filled into the cylinder through the neck 19.

 Through the hole 18, air from the tube 16 is supplied to mix the working fluid in the cylinder 1.

 From the cylinder 1, the working fluid with the help of compressed air is pumped through the processed pipe 3 into the cylinder 2 with open taps 6 and 7.

 As the cylinder 2 is filled with the working fluid, the air from the cylinder 2 exits through the upper hole 17 in the tube 16 installed in the cylinder 2, enters the tube 12 and is drained through the pipe 15 through a two-way valve 13.

 After releasing the cylinder 1 from the working fluid, the valve 13 switches and the process can go in the opposite direction.

 At the end of the process, the taps 6 and 7 are closed and the processed pipe 3 is removed.

 During pumping of the working fluid, it is possible to turn on the heating 20 of the processed pipe 3.

 In order to prevent the working fluid from remaining in the processed pipe 3, the pipe and taps 6 and 7 with pneumatic clamps 4 and 5 must be installed above the initial level of the working fluid filled in the cylinder 1.

 For the possibility of processing pipes of various lengths, the cylinder 2 is made movable by installing a flexible sleeve 14.

 The creation of the installation seems quite real to the Author on the basis of an automated installation designed for the abrasive cleaning and polishing of the internal surfaces of tubes, for example, the airborne system of an aircraft (factory code C), designed according to the idea set forth by the author in <2> and manufactured at the State Enterprise "Leningradsky Severny Zavod" 254.00.00).

 In addition, the same idea was used in the UG3-1A installation for waterjet pipe cleaning developed at NITI.

Claims (1)

 A method of painting the inner surfaces of pipes by pumping a liquid coating material through a pipe to be processed, which means that the coating material is pumped in both directions the required number of times to complete the coating process using compressed air.