What is the proper vinyl sheet pile driving method for different soil types?

“Pitch and drive” method is the most practical way of pile driving in loose soils especially when using short piles. Also called “set and drive”, this method installs piles one by one. However, with only one interlock in control, sheet piles have high tendencies of rotating from the axis and leaning forward or backward. Panel driving is recommended for the dense deposit of sands and compact cohesive soils such as heavy clay or in presence of obstructions. In this method, a number of piles are interlocked together before driving. The panel of piles is supported by guide frames and driven gradually in sequence, sometimes in a staggered manner. The method can achieve installations of longer piles in more difficult ground conditions with better results in sheet pile alignment and verticality. In cases of difficult ground conditions such as hard strata and the presence of obstructions, driving assistance is employed along with a proper selection of driving method and equipment. Jetting and drilling help by loosening or eliminating obstructions by creating pressure right under the tip of the sheet pile being driven. Long and slender PVC sheet piles require steel mandrels as supports when driven in such conditions. Mandrel, which shape is similar to sheet pile profiles, increases the rigidity of Plastic Sheet Pile and supports the weight of the driving equipment such as a vibro-hammer.

What is the proper machine to drive piles in different conditions?

Impact driving is suitable for all soil types but appears to create the highest degree of stress to sheet piles. It is more appropriate to cohesive soils and soft soils such as silts and peats, loose medium to coarse sand, and gravels free of rock inclusions. Drop hammers such as the hydraulic hammer are the common types of impact-driving machinery. Driving using vibratory hammers is ideal for non-cohesive or granular soils such as soft soils and round-grained sand or gravel. It has also shown satisfactory performance in sandy, silty, or softer clay soils. It is less effective in angular-grained materials and soils with a firm consistency. With the introduction of vibration, however, the sub-soil can be further compacted, increasing penetration resistance and ultimately-refusal. If this is the case, driving aids like jetting and drilling might be necessary.

What are the pvc sheet pile selection criteria for soil condition of different hardness?

General rule of the thumb: “the harder the soil, the stronger and stiffer sheet pile section should be used”. Driveability of a pile section is a consequence of its cross-sectional properties (thickness, depth, and width), designed shape, length, grade, and the applied load. Hardness of soil strata characterized by SPT or CPT values is used to predict soil resistance which is essential in the calculation of driving force to be applied. Knowing the range of force from the selected driving machine, corresponding sheet pile sections can be picked according to their yield strength and elastic modulus.

How should I choose a sheet pile section for soils with, say, SPT Value, N=30? Can I still consider using vinyl or shift to steel?

Every sheet pile material has a design purpose, strengths, and areas of improvement. The availability of different materials denotes the need for a special material for a specific application. Plastic or synthetic sheet piles for example are known for being light and corrosion-resistant; Steel sheet piles are recognized for their extraordinary strength and versatility; and so on.

Mar 13, 20226 min read

What to Look for When Choosing Steel Pipes?

Steel pipes come in many types according to different classifications. We have carbon steel, black steel, alloys, and stainless steel as per chemical composition. According to the manufacturing process, steel pipes can be seamless and welded.

Welded steel pipes are manufactured using electric resistance welding (ERW), high-frequency induction welding (HFI), or longitudinal submerged arc welding (LSAW). Steel pipes are also categorized with respect to their properties against corrosion. Stainless steel and black steel are types with inherent corrosion-resistant surfaces, galvanized or painted steel depending on their coatings, such as molten zinc or paint.

Basically, knowing the application or use of the material should be enough to decide what kind of steel pipes to choose or buy. It should be straightforward: purchasing a thick-walled pipe when dealing with high pressures, choosing galvanized or stainless when a steel pipe will be used in a highly corrosive environment, or going seamless for liquid line projects.

However, choosing steel pipe is never simple, especially for significant investments, critical infrastructures, and wherever we wish for the best return value out of our hard-earned money. Project or investment value is not just the totality of the construction cost but the summary of all expenditures throughout its service life, including maintenance costs.

Whether intended for piping, automotive, general construction, or other industries, narrowing the list of appropriate steel pipes requires a closer look and comprehension of their qualities. Below tabulation of crucial information may be of help.

Background

Carbon Steel - Accounts for 90% of total steel production. It is considered the most cost-effective steel pipe due to its relatively affordable iron and carbon elements.

Galvanized Steel - Known as the most durable steel pipe in the market

Black Steel - Considered the most highly stable structured steel pipe

Alloy - It has alloying elements that make steel lighter, sturdier, and more resistant to stress and pressure and also has enhanced weldability and ductility

Stainless Steel - Stainless steel pipes are widely known for their considerable corrosion resistance and aesthetic appearance

Chemical Components

Carbon Steel – Alloys of carbon and iron, containing up to about 2% carbon and up to 1.65% manganese by weight

Galvanized Steel – Same components of ferrous steels. They can be iron or steel.

Black Steel – Has low-grade carbon content.

Alloy – Alloying elements like nickel, chromium, manganese, copper, vanadium, molybdenum, silicon, tungsten, and many more, amounting to 1 to 50% by weight

Stainless Steel - Contains between 10 to 20% chromium – the element that prevents corrosion; and a maximum of 0.1 to 1% of carbon. It also contains manganese, silicon, nickel, and molybdenum.

Production Process

Carbon Steel - Seamless or Welded

Galvanized Steel - Seamless or Welded

Black Steel - Seamless or Welded

Alloy - Seamless or Welded

Stainless Steel - Seamless or Welded

Weight

Carbon Steel - 7.85 tons per cubic meter

Galvanized Steel - Weight of base material (iron or steel) + 15% due to zinc coating

Black Steel - 7.80 tons per cubic meter

Alloy - Reduces the weight of pure metals depending on what alloying elements are used.

Stainless Steel - 8.0 tons per cubic meter

Ideal Applications

Carbon Steel - Ideal for construction applications and other uses like liquid and gas lines under high temperatures, tools, ships, automobiles, and more

Galvanized Steel - Mainly used in the transportation of coal gas, steam, and water

2Equally excellent for a wide range of construction applications, including marine and weather-exposed environments

Black Steel – 1) Preferred in areas that demand high stability like liquid and gas transportation due to high strength and corrosion resistance.

- 2) They are also used in many construction applications

Alloy - *Generally utilized in the piping industry for extreme conditions, as well as in Oil and Gas and power generation, due to its toughness.*Alloy steel pipes also has numerous applications in the building and construction industry

Stainless Steel - Used in industries where corrosion and oxidation resistance are significant and require high strength, including ships energy, poles, water treatment, pharmaceutical, and Oil and Gas applications

Areas of Limitation

Carbon Steel - Not suitable for extreme conditions or high pressure

Galvanized Steel - 1) Not advisable to be used in gas lines because the zinc coating can clog the pipe when it begins to flake;

- 2) Later found to be unrecommended for water transportation due to the contamination developed after years of service.

Black Steel - Less suitable for applications requiring aesthetic appearance

Alloy - Occasions may be rare, but alloys are less recommended when excellent electrical or heat conductivity is required

Stainless Steel - Applications involving contact, friction, or abrasion should be avoided to maintain the integrity of the chromium layer that keeps the material rust and corrosion resistant

Strengths

Carbon Steel - It is a robust, high-strength, and shock-resistant metal. Unlike many other metals, it does not decay. Carbon steel pipe comes in various sizes, can be bent to curves, and may be utilized almost everywhere. This metal is frequently the most practical choice due to its strength, affordability, and safety.

Galvanized Steel - Galvanized steel pipes are designed to prevent rust and corrosion. Galvanization or zinc coating is less costly than other protective coating methods. It is highly durable; hence it can reach a service life beyond 50 years under normal conditions and at least 25 years under severe and extreme environments.

Black Steel - 1) These steel pipes are manufactured with increased tensile strength and productivity. Fluctuating pressures or shock pressures cannot bend or break them down. In other words, these pipes are shatterproof in transport and in-service;

2) Because of high strength, these pipes can come with thinner walls, maximizing inside diameter or carrying capacity;

3) Alloy steel pipes can prevent fires better than galvanized steel pipes.

Alloy - 1) Alloy steel pipes are corrosion-resistant;

2) have a higher percentage of ductility and weldability.

3) They can be lighter and have a higher melting point than other steel, which is a positive factor in the safety of buildings and structures against fire and seismic activities.

Stainless Steel - 1) Stainless steel pipes are corrosion-heat-impact resistant;

2) They are also favorable for the food industry since they have antimicrobial properties that are genuinely great for transporting food products in processing systems.

*They are also easy to manufacture, install, and maintain. The flexibility of stainless steel makes it possible for manufacturers to generate custom-shaped pipes and pipe fittings. Stainless steel pipes are likewise easy to install, saving industries from lengthy preparation time.

Weak Points

Carbon Steel - It is more prone to rust compared to other steel. Because of its strength, it is more challenging to work with

Galvanized Steel - Galvanized steel pipes corrodes from inside out after some time, resulting in clogged lines and contamination of carried liquids, especially water.

Black Steel - Black steel pipes are not corrosion-resistant and are less attractive.

Alloy - Alloy steel pipes have lower strength compared to carbon steel

Stainless Steel - Stainless steel pipes are more expensive due to the integration of superior alloying materials and the complexity of manufacturing processes and types of machinery

Initial Cost

Carbon Steel - With anti-corrosion measures, the cost is higher compared to black steel pipe

Galvanized Steel - More expensive than iron and steel pipes due to the zinc coating provided

Black Steel - Considered the cheapest steel pipe.

Alloy - More costly compared to iron and steel pipes depending on the nature and quantities of alloying substances

Stainless Steel - Reckoned as the most expensive among steel pipes

Maintenance/Anti-Corrosion

Carbon Steel - 1) Initially requires galvanizing, Painting, Cathodic Protection, or combinations to stay longer; 2) Maintenance of protective coating is required periodically or as physically necessary.

Galvanized Steel - Monitoring is required to zinc coating, and repairs are necessary when damage, rust, or deterioration is detected.

Black Steel - Requires lesser time and effort of maintenance

Alloy - Maintenance is convenient and cheap

Stainless Steel - Maintenance is convenient and cheap.

Each classification and type of steel pipe has suitable areas of application, dominant features, and inferiorities.

Ultimately, choosing a suitable steel pipe is a matter of design priorities - what characteristics of steel pipe have the utmost importance, and what features are given with the slightest consideration? The building blocks of steel might be simply iron and carbon; however, alloying processes have allowed us to customize steel into desired properties that suit almost all extent and complexity of applications in metallurgy.

Be an intelligent buyer by learning more about the types of steel suitable for your specific piping requirements. Choose a supplier that offers stellar inventory, value-added services, and experience in the global market. Choose ESC!

ESC steel piping products have it all – steel piling pipes, combination walls, structural steel pipes, loading steel pipes, including corrosion protection solutions. ESC produces a wide range of steel pipes up to 4,267mm diameter and 100mm thickness by LSAW, SSAW, and ERW manufacturing processes.