Just how to stop internal rust of gas pipeline ？

For natural gas pipe, inner rust is the electrochemical reaction of recurring water as well as acid gas in the pipeline similar to galvanic cell as well as the chain reaction that ruin the steel lattice. Both of these reactions trigger the pipe wall surface to loosen up, fall off and perforate, which can no more endure the stress of natural gas in the pipeline. In sensible application, a kind of covering can not be very good defense, or can not meet the requirement such as anti-corrosion, weather resistance, great look, and for that reason most several coating on metal surface finishing interact to form a whole system, including guide layer, the center layer, paint, finishing one or a number of times each layer specifically as needed, and there is only single layer such as powder finishes can meet the various demands at the same time.

The anti-corrosion finish of natural gas pipe ought to have the complying with buildings: reliable electric as well as water insulation; Not limited by finishing methods; Good attachment to pipeline surface; Resistant to harm during installment, storage space as well as transport; Resistance to chemical tool damage; Easy to repair; Long service; Environmentally pleasant and also non-toxic. At present, the anti-corrosion layers for long distance transportation pipes mostly consist of coal tar paint, 2LPE, 3LPE, fused epoxy powder (FBE), and also double-layer merged epoxy powder (FBE double-layer) finishing.

Coal tar enamel.

Coal tar paint covering is the very early secondhand layer, it's characterized by good insulation performance, low water absorption, resistance to microbial corrosion as well as plant origin penetration, long service life as well as small cost. Nonetheless, its mechanical stamina is reduced and also has a tiny ideal temperature level array, it may escape hazardous gases and calls for strict smoke treatment. Over the last few years, it has been slowly changed by other covering layers as a result of the limitation of environmental protection.

2LPE.

2LPE has excellent insulation performance, low water absorption, high mechanical toughness, hard wear resistance, acid, alkali, salt and also bacterial rust, temperature adjustment resistance.

However, there are also disadvantages: simple aging, bad adhesion with the steel tube surface area, inadequate anti-cathodic stripping performance. Electrostatic shielding of PE layer is not for outside present cathodic protection.

3LPE.

The three layers of PE anti-corrosion layer combine the advantages of high thickness polyethylene and fused epoxy powder. The epoxy powder is firmly integrated with the surface of the steel pipe, and also the high density polyethylene is immune to mechanical damages. The sticky layer between both layers makes the three type a composite framework of molecular bond, which understands the excellent combination of rust resistance and mechanical buildings. It is the first choice for massive natural gas transportation pipeline design.

Blend adhered epoxy powder (FBE).

The PBE covering has strong bonding with the surface area of the steel pipe, good insulation performance, high mechanical toughness, temperature level adjustment resistance as well as chemical deterioration resistance, and also can be used in a selection of extreme atmospheres. The main negative aspect is inadequate ultraviolet resistance as well as the thin overburden layer (0.35 ~ 0.50 mm). The double-layer FBE is similar to 3PE, with excellent compatibility, smooth surface of the covering layer, which can prevent cathodic shielding.

So, how does the finishing safeguard the inner wall surface of the gas pipe? We currently know that steel rust results from the activity of the ecological medium on the metal surface to produce electrochemical response or chain reaction, the effect of the finish on the pipeline is attained by preventing the above reactions:.

( 1) Shielding: Many coverings on acid, alkali, salt and various other harsh media show chemical inertia, and the high dielectric consistent to stop the formation of rust circuit, so the metal surface area finishing to the metal surface and the atmosphere isolation and also protecting the harsh medium. It needs to be mentioned that the polymer finishing is breathable and very closely related to its framework.

( 2) Passivation slow-moving release: With the aid of antirust pigment in the covering as well as the steel surface reaction, make it passivation or create protective compounds; In enhancement, several oils can likewise function as organic rust inhibitors by creating degradation items under the catalytic activity of steel soaps.

( 3) WLDSTEEL Electrochemical defense: The finishing capacity is less than iron steel filler (such as zinc) will certainly compromise the cathodic protection of the anode, as well as the atmospheric rust products of zinc alkali zinc carbonate is relatively stable, can be shut, plug the last space.

So exactly how to stop the corrosion of the internal wall of the gas pipeline? We can prevent by doing this: to start with, the gas drawn out from the ground goes through a series of procedures such as desulphurization and also dehydration, prior to it gets in the long-distance pipe. Secondly, the effective inner finish of the pipeline can reduce deterioration, gas transmission resistance as well as cleaning time.