Marine Seamless Steel Pipe

Marine Seamless Steel Pipe

Marine seamless steel pipes are highly specialized conduits designed to meet the demanding needs of ship systems.

 The pipes conform to requirements of ASTM, ASME, SPI, EN, JIS, DIN, GB, RS, ABS, BV, CCS, RINA… We can customize pipes in accordance with your requirements, available for large diameter, small diameter, heavy wall, thin wall… Please contact us for more information!

Two systems of ship and marine engineering demand roughly in three types of steel pipe:

Different ship and marine engineering, both conventional systems have a dedicated system.

Ship service life of 20 years. Many of the conventional system, bilge water, ballast, dewater sewage, air, measurement, injection, domestic water, fire, cargo oil stripping, breathable, inert gas, heating, washing, foam extinguishing sprinkler, vapor, liquid level telemetry, valve remote control systems, special ships also include a dedicated system for the transportation of liquefied petroleum gas (LPG), liquefied natural gas (LNG). Marine engineering service life of up to 30 years, or even longer. Marine engineering in addition to the conventional system, special drilling equipment systems, crude oil / LPG / LNG processing workflow system, special mooring system, flare system, and so on. It has been statistics, ship pipe annual consumption of 450 million tons, about 440,000, its standards are GB, YB, CB, 70% of the steel pipe connection. Only a 30-ton very large crude oil pipes for the amount of up to tens of kilometers, only steel pipe usage (including), there are about 1,500 tons, of course, the amount of 40,000 tons relative to the hull structure or limited. In addition, taking into account the same ship, to the construction of ships, as well as many other ships, so the cumulative dosage is also a lot of. And a 300,000 tons-class number of large FPSO pipe over 30,000, more than 90 km in length, which is the same tonnage level 2 to 3 times. Therefore, the shipbuilding industry has become a big user of steel pipe market.

Steel pipe in construct

Steel tube marine engineering applications, in addition to the above conventional system with a dedicated system, many constructed a large number of steel pipes, such as jacket, underwater steel piles, Casing, mooring bracket, helicopter platform, torch tower. Type of steel pipe, material specifications, with the same diameter, reducers, different wall thickness, as well as a large number of Y, K, T-managed nodes. Such as jacket, steel piles, wellhead impermeable sleeve, mostly large diameter steel pipe sizes, are generally made of rolled steel. Their material for E36-Z35, D36-Z35, E36, D36. Such steel pipe standards have not with YB, CB, and mainly is GB712-2000. The production of steel pipe structure steel pipe manufacturing practice SY/T10002-2000 developed by China’s Petroleum Industry Standards and Technology Commission (CPSC). Since China does not have the specialized enterprises, are usually the purchase of steel plate from construction units, self-molding process.

Specifications of marine seamless steel pipe table 1 grade of seamless steel pipe (pressure tubing)

Pipe Range I
Designed Pressure(Mpa) Designed Temperature (℃) Designed Pressure (Mpa) Designed Temperature (℃) Designed Pressure (Mpa) Designed Temperature (℃)
Steam and Hot Oil 1.6 300 0.7-1.6 170-300 0.7 170
Fuel Oil 1.6 150 0.7-1.6 60-150 0.7 60
Other Media 4 300 1.6-7.0 200-300 1.6 200


When the designed pressure and temperature reach the ones in the above Class I, this steel pipe belongs to Class I pipe. If it meets the pressure and temperature of Class II, it is defined to be the Class II pipe.

Other media refer to air, water, lubricating oil and hydraulic oil.

Class III seamless steel tubes can be manufactured in accordance with the national standards approved by the ship inspection department.

1) As for the seamless steel pipe for boiler and super heater purpose, the working temperature of wall thickness does not exceed 450℃.

2) The dimension of marine seamless steel pipe should firstly select the general steel pipe size in the first group of GB/T7395-1998 table one. The outside diameter of steel tube should choose the standard outside diameter size in the first series of GB/T7395-1998. We can also produce pipes with other specifications not appear in the GB/T7395-1998 table one.

Steel pipe for special purpose

Special purpose steel special steel pipe used in the specific working environment and the working medium. Undersea pipeline is typical specialty steel pipe, the demand for larger, high strength, small tolerances, good corrosion resistance. Currently, the pipeline production is only in its infancy, because the welding materials, corrosion resistance or less Specifications (diameter and wall thickness), expensive, etc. China’s offshore crude oil need insulation transport. The past, using the double pipe insulation structure, safe and reliable. But as a protective pipe steel pipe is very economical, and offshore pipe laying ago, have to carry out internal and external pipe welding, greatly reducing the efficiency of the pipe laying, to cause installation costs increase exponentially. Into the 21st century, it has launched a concrete counterweight steel pipe.

Its structure is (from inside to outside):

anti-corrosion layer of steel, epoxy powder (FBE), polyurethane insulation, polyethylene (PE) jacket tube, reinforced concrete counterweight layer (the internal configuration of the steel mesh). This type of special steel, China has imported from abroad, such as the Bohai Penglai 19-3 oil field, a project using Malaysian BREDEROPRICE company products. China after research and testing, and in 2002 built in Tanggu, China’s first concrete with heavy steel pipe production line, has thousands of kilometers of pipelines for offshore oilfield products. It is reported that, using this steel per kilometer subsea pipeline to reduce the cost of 50 million to 100 million, and greatly reduce the cost of offshore oilfield development, so that a number of marginal oil fields to be cost-effective to develop.

Specifications of Marine Seamless Steel Pipe Table 1 Grade of Seamless Steel Pipe (Pressure Tubing)

Classification of ships

Seamless steel tube and pipe for ship building usage and Chemical compisition(%)

Society Standard or usage Steel grade C Si Mn P S Cr Ni Cu Al Mo V P+S
GLR Non alloly GL-R 410 ≤0.21 ≤0.35 ≤1.4 ≤0.025 ≤0.02 - - - ≥0.020 - - -
GB 18248 37Mn 0.34~0.40 0.1~0.30 1.35~1.65 ≤0.03 ≤0.03 ≤0.3 ≤0.3 ≤0.2 - - - ≤0.055
EN 10297 34CrMo4 0.3~0.37 ≤0.4 0.6~0.90 ≤0.035 ≤0.035 0.9~1.20 - - - 0.15~0.30 - -
DNV for pressure ASTM A53/A53M A53B ≤0.3 - ≤1.2 ≤0.05 ≤0.045 ≤0.4 ≤0.4 ≤0.4 - -
0.15 0.08
ABS for pressure Grade 3 ≤0.3 - ≤1.2 ≤0.05 ≤0.045 ≤0.4 ≤0.4 ≤0.4 - ≤0.15 ≤0.08 -
BV for pressure 410HB ≤0.21 ≤0.35 0.4~1.20 ≤0.04 ≤0.04 - - - - - - -
LR for pressure 410 ≤0.21 ≤0.35 0.4~1.20 ≤0.045 ≤0.045 ≤0.25 ≤0.3 ≤0.3 - - -
KR for pressure RST138 ≤0.25 ≤0.35 0.3~0.90 ≤0.04 ≤0.04 - - - - - - -
RST142 ≤0.3 0.3~1.00 ≤0.04 ≤0.04 - - - - - - -
RST238 ≤0.25 0.1~0.35 0.3~1.10 ≤0.035 ≤0.035 - - - - - - -
RST242 ≤0.3 0.3~1.40 - - - - - - -
RST249 ≤0.33 0.3~1.50 - - - - - - -
RST338 ≤0.25 0.3~0.90 - - - - - - -
RST342 ≤0.3 0.3~1.00 - - - - - - -
NK for pressure grade 1 No3/ KSTPG 42 ≤0.3 ≤0.35 0.3~1.00 ≤0.04 ≤0.04 - - - - - - -
CCS for pressure 360 ≤0.17 ≤0.35 0.4~0.80 ≤0.04 ≤0.04 ≤0.25 ≤0.3 ≤0.3 ≤0.10
410 ≤0.21 ≤0.35 0.4~1.20 ≤0.04 ≤0.04 ≤0.25 ≤0.3 ≤0.3 ≤0.10
460 ≤0.22 ≤0.35 0.8~1.40 ≤0.04 ≤0.04 ≤0.25 ≤0.3 ≤0.3 ≤0.10
490 ≤0.23 ≤0.35 0.8~1.50 ≤0.04 ≤0.04 ≤0.25 ≤0.3 ≤0.3 ≤0.1

residual elements:Cr≤0.25%, Mo≤0.10%, Ni≤0.30%, Cu≤0.30%aggregate≤0.70%


Model N0.of major steel tubes

【H】 Ceramic lined pipe

Ceramic lined pipe is made through self-propagating high-temperature synthesis (SHS) technique.

【H】 Cast basalt lined steel pipe

Cast basalt lined steel pipe is composed by lined with cast basalt pipe, outside steel pipe and cement mortar filling between the two layers.

【H】 Ceramic Tile Lined Pipes

Ceramic tile lined pipes have very uniform coating of specially formulated ceramic material that is affixed to the inner of the pipe.

【H】 Rare earth alloy wear-resistant pipe

The material of the rare earth alloy wear-resistant pipe is ZG40CrMnMoNiSiRe, which is also the grade of rare earth alloy steel.

【H】 Tubes Erosion Shields

Tubes Erosion Shields are used to protect boiler tubing from the highly erosive effects of high temperatures and pressures thereby greatly extending tube life.

【H】 ASTM A213 T91 Alloy Tube

The ASTM A213 T91 seamless tubes are primarily used for boiler, superheater, and heat-exchanger.

Ni-Hard Wearback Pipes Ni-Hard Wearback Pipes