Exactly How To Prevent Interior Corrosion Of Natural Gas Pipeline

For gas pipeline, interior rust is the electrochemical response of residual water as well as acid gas in the pipe similar to galvanic cell and the chain reaction that damage the metal latticework. Both of these reactions create the pipeline wall to loosen up, fall off and pierce, which can no longer withstand the pressure of natural gas in the pipeline. In useful application, a kind of coating can not be excellent security, or can't fulfill the requirement such as anti-corrosion, weather condition resistance, good look, as well as consequently most numerous covering on metal surface coating work together to form a whole system, including primer layer, the center layer, paint, layer one or several times each layer specifically as required, and also there is just single layer such as powder finishes can fulfill the different needs at the exact same time.

The anti-corrosion coating of gas pipeline need to have the complying with residential or commercial properties: effective electric as well as water insulation; Not limited by coating methods; Good attachment to pipe surface area; Resistant to damage throughout installment, storage and transportation; Resistance to chemical tool damage; Easy to fix; Long solution; Environmentally pleasant and safe. Presently, the anti-corrosion coverings for cross country transport pipes primarily include coal tar paint, 2LPE, 3LPE, integrated epoxy powder (FBE), and also double-layer integrated epoxy powder (FBE double-layer) finishing.

Coal tar enamel.
Coal tar paint covering is the very early pre-owned finish, it's identified by great insulation performance, low tide absorption, resistance to bacterial corrosion as well as plant origin penetration, long service life and low cost. Nevertheless, its mechanical strength is low and has a tiny appropriate temperature variety, it might get away toxic gases and calls for rigorous smoke therapy. In recent years, it has been gradually replaced by various other covering layers due to the restriction of environmental protection.

2LPE.
2LPE has great insulation performance, low water absorption, high mechanical stamina, hard wear resistance, acid, antacids, salt as well as bacterial corrosion, temperature level change resistance.
Nevertheless, there are likewise disadvantages: very easy aging, inadequate attachment with the steel tube surface area, bad anti-cathodic removing efficiency. Electrostatic protecting of PE layer is not conducive to external existing cathodic security.

3LPE.
The three layers of PE anti-corrosion layer combine the advantages of high density polyethylene and also merged epoxy powder. The epoxy powder is securely combined with the surface area of the steel pipeline, and also the high density polyethylene is resistant to mechanical damage. The sticky layer in between the two layers makes the three type a composite framework of molecular bond, which recognizes the good mix of corrosion resistance and also mechanical homes. It is the first choice for large natural gas transportation pipeline design.

Blend adhered epoxy powder (FBE).
The PBE covering has solid bonding with the surface area of the steel pipe, good insulation efficiency, high mechanical toughness, temperature level change resistance and chemical rust resistance, and also can be used in a range of rough environments. The primary downside is inadequate ultraviolet resistance and the slim overburden layer (0.35 ~ 0.50 mm). The double-layer FBE resembles 3PE, with excellent compatibility, smooth surface of the covering layer, which can prevent cathodic protecting.

So, just how does the finishing protect the internal wall of the gas pipe? We already know that metal rust is due to the action of the environmental tool on the steel surface to generate electrochemical response or chain reaction, the effect of the finishing on the pipeline is accomplished by hindering the above reactions:.
( 1) Shielding: Many coatings on acid, alkali, salt and also other destructive media reveal chemical inertia, and also the high dielectric continuous to stop the development of rust circuit, so the steel surface finish to the metal surface area and also the atmosphere seclusion and securing the corrosive medium. It has to be explained that the polymer covering is breathable and also very closely pertaining to its framework.
( 2) Passivation slow-moving release: Discover More With the help of antirust pigment in the finishing and also the metal surface area response, make it passivation or create protective substances; In enhancement, several oils can also function as natural rust preventions by producing deterioration items under the catalytic activity of steel soaps.
( 3) Electrochemical defense: The layer potential is lower than iron steel filler (such as zinc) will sacrifice the cathodic security of the anode, as well as the climatic rust products of zinc alkali zinc carbonate is fairly stable, can be shut, connect the last void.


So how to prevent the deterioration of the internal wall surface of the gas pipeline? We can stay clear of by doing this: to start with, the gas drawn out from the ground goes through a series of processes such as desulphurization and also dehydration, prior to it goes into the long-distance pipe. Secondly, the efficient interior covering of the pipe can decrease rust, gas transmission resistance as well as cleaning time.