Pipeline failure and maintenance-10

Release time:

2024-04-26

How about the new technology of plugging pipeline under pressure?

A: plugging under pressure is a new advanced equipment maintenance technology. When a part of equipment pipeline, valve and flange in the production device leaks, it can quickly block the leakage with pressure and temperature without stopping and affecting the production, so as to ensure the stability of production, make the equipment system run for a long period and improve the economic benefits. The application range of plugging with pressure is from vacuum to 32Mpa, and the temperature is - 20 ~ 650 ℃. Because of its large applicability, simple operation and good effect, it has developed rapidly in recent years and has been widely used in industries and departments of petroleum, chemical industry, electric power, metallurgy, medicine and other processes.

(1) Plugging principle: when the pipeline is running under pressure, a special clamp is installed on the leaking part, and the hydraulic pump is used as the power source (the pressure can reach 60MPa), to push the plunger push rod in the high-pressure injection gun, and to press the special sealant onto the leaking part. The grease in the sealant is carbonized rapidly to solidify the asbestos fiber, and a new sealing structure is established, so as to quickly eliminate the leakage on the pipeline and achieve the purpose of sealing.

(2) Special tool special tool is composed of hydraulic pump that produces power source, high-pressure injection gun that injects sealant, high-pressure hose, pressure gauge and connecting piece, etc.

The main special tool is the high-pressure injection gun. The high-pressure injection gun is composed of hydraulic cylinder, plunger push rod, connecting nut and injection cylinder.

The pressure oil from the hydraulic pump acts on the plunger push rod of the high-pressure injection gun to produce a high driving force. The sealant installed in the injection barrel is squeezed into the leakage part through the injection hole on the special fixture.

(3) The special fixture is specially manufactured according to the shape of the leakage part, which is installed on the leakage part to contain the sealant, and bears the pressure of the leakage medium and injection sealant. When the pressure is less than 2MPa, the special clamp can be replaced by steel banding. The fixture is generally made into two semicircles, and several injection holes for injection sealant are reserved as required.

The material selection, design and manufacture of the special fixture must meet the requirements of the supervision regulation on safety technology of pressure vessel.

(4) Sealant sealant shall have enough swelling resistance, corrosion resistance, temperature resistance, water solubility resistance, air permeability, good fluidity and high and low temperature curing adaptability to the blocked medium. It must also be non-toxic, non corrosive, non flammable and explosive. The sealing shape can be manufactured according to the specification and size of the injection gun. For example, 18mm x 75 (95) mm, 24mm x 95mm, etc.