ASME SA335 / ASTM A335, Chrome-Moly pipe is a seamless ferritic Alloy-Steel Pipe produced in nominal or minimum wall thickness for high temperature service. Pipe ordered to this specification shall be suitable for bending, flanging, similar forming operations and for fusion welding.
Chrome Moly products are named so due to the presence of the two elements Molybdenum (Mo) and Chromium (Cr). Cr raises the properties of tensile, yield and hardness (at room ambient temperatures) making it ideal for combatting oxidation in high temperature services. Mo is known, amongst other attributes, to improve the hardenability, reduce brittleness, strengthen the elastic limit, increase temperature strength and improve weldability in certain situations. Sometimes referred to as “P Grade” materials, chrome moly pipe comes in more than 17 grades with the most widely used P-Grades being P5, P9, P11, P22 and P9.
It is commonly known that A335 / SA335 material is extensively used in a variety of plants & processes across the globe including refineries, power plants, petro-chemical plants, hydrocrackers, cokers, high and super high temperature lines, reheat lines, distillation, oil field services, etc. In general, the most commonly used P grades in refineries are P5 & P9. The most commonly used P grades in the power generation industry and petro-chemical plants are P11, P22 & P91. A quick perusal, however, of what appears to be similarly designed facilities will result in findings that they do not necessarily use the same piping specifications. For example, there are many different designs and piping systems in what be generically called a “natural gas processing plant”.
STD, 40, XH, 60, 80, 100, 120, 140, 160, XXH
Wall thicknesses up to 4", intermediate, average and min walls
Chrome moly, ferritic alloy, creep and heat resistant
Temprature & Allowable Strees of P1/P2/P5/P7/P9/P11/P12/P21 & P22 Pipe:
Operating temperature and allowable stresses in pipe walls for seamless ferritic alloys steel pipes
are indicated in the diagram below:
|Model No.︰||ASP p1-10|
|Brand Name︰||ASTM/ASME A335/SA335 P1,P2,P5,P9,P11,P22,P23,P91,P|
|Country of Origin︰||-Tenaris-Italy,|
|P1 Pipe Price︰||-USD 1700 per Ton|
|Minimum Order︰8 Ton|
Chrome-moly pipe has become a standard in industries such as power generation, chemical processing and petroleum refineries, not only because of its corrosion resistance and high-temperature strength, but also for its cost effectiveness. In many applications, it is a viable alternative to a more costly stainless steel pipe.
Choosing filler metals to weld chrome-moly pipe requires the same principle consideration as with any material: match the chemical and mechanical properties in a way that yields the strongest, safest and longest lasting welds. Specific low alloy SMAW electrodes. They provide the low carbon, low hydrogen properties that prevent welds from corroding and/or cracking on critical piping applications, as well as the necessary strength to withstand high pressure and temperatures.
the more common grades are P11, P21, P22, P91 and P92, some of which can withstand service temperatures over 600 degrees Celsius and have wall thicknesses ranging from 1/8 inch to eight inches. The amount of chrome, molybdenum or other alloying elements determines the assigned grade of chrome-moly. These particular grades contain a range of 1¼ to 9 percent chrome and ½ to 1 percent molybdenum, with those containing more chrome providing the most corrosion and temperature resistance.
When welding chrome-moly pipe, regardless of the grade and/or the filler metal being used, it is important to maintain specific preheat and interpass temperatures. Consistent temperatures help conserve strength and crack resistance under extreme service conditions. Recommended preheat temperatures range from 121 to 204 C according to the wall thickness,Recommended Practices for Welding of Chromium-Molybdenum Steel Piping and Tubing,’ preheating practices should always be observed, even before tack welding. It is especially important to preheat prior to repairing P21 and above grade chrome-moly pipe that has been in service,
Maintaining interpass temperatures is also important. A range of 177 to 316 C is typical, depending on the grade of chrome-moly and its thickness, but most importantly, upon the required welding procedure.
Post-weld heat treating (PWHT) or stress relieving is also recommended. PWHT requirements are generally 621 to 760 C for one hour. PWHT helps rid the weld of hydrogen that may have been picked up either from the filler metal, the base metal, or the atmosphere, and can help minimize the chances of cracking.
Low alloy SMAW electrodes are your best choice for chrome-moly pipe welding repairs, because they are easily portable. They can also reach into the small physical confines of existing chrome-moly piping systems.
For P11 Pipe welding:(1 ¼% Cr – ½% Mo) chrome-moly pipe, use either an AWS E8018-B2 H4R or E8018-B2L H4R SMAW electrode, as both are formulated for applications subject to high heat and/or humidity. They also resist hydrogen pick up that can lead to cracking or starting porosity. The E8018-B2L H4R stick electrode contains a lower amount of carbon, which further protects against cracking. Both electrodes work especially well on boiler and similar piping repairs that require weld tensile strengths above 80,000 psi. On the average they offer tensile strengths in the range of 90,000 to 98,000 psi.
P21 or P22 Pipe Welding:(2 ¼% Cr – 1% Mo) or P22 (3% Cr – 1% Mo) pipe requires SMAW electrodes with higher chrome content and higher tensile strengths than those used for P11 pipe. Options include AWS E8018-B3L, E9018-B3 H4R or E9018-B3L H4R electrodes, which are good for boiler work and general pipingapplications. These SMAW electrodes yield tensile strengths in the range of 105,000 to 110,000 psi and generally feature a special moisture resistance coating that protects against hydrogen pick up in service conditions of high humidity or heat.
Finally, when repairing P91 pipe (9% Cr – 1% Mo or P92 (9% Cr – 2%W – ½% Mo, V) pipe, choose a SMAW electrode formulated to improve creep resistance. Creep is any deformity (buckling, warping, etc) caused by stress and/or heat during the welding process, and higher strength chrome-moly is prone to this occurrence. AWS E8018-B8 H4R, E8018-B8L H4R or E9018-B9 SMAW electrodes can help provide that protection and are good choices for petrochemical or petroleum pipes or other surface applications exceeding service temperatures of 149 C. They yield tensile strengths between 100,000 and 110,000 psi.
Fabrication of p11 Pipe:
When fabricating P11 chrome-moly pipe, the following flux-cored wires can be used: AWS E80T1-B2C/M, E80T5-B2C/M, and E81T1-B2C/M, all of which offer excellent strength, and creep and corrosion resistance in high service temperature applications. They are comparable in their characteristics to an E8018-B2 SMAW electrode, but will yield different tensile strengths according to the shielding gas used. A ‘C’ at the end of the AWS classification indicates the wire requires 100% CO2, whereas a ‘M’ indicates the wire uses a 75 percent argon/25 percent CO2 mixture and provides higher tensile strengths.
The main low alloy flux-cored wires for welding P21 and P22 chrome-moly pipe include AWS E90T1-B3C/M and E90T5-B3C/M for flat and horizontal welding, and the E91T1-B3C/M H4 for all-position welding applications. The E91T1-B3C H4 requires 100 percent CO2 and the E91T1-B3M H4 uses 75 percent argon/25 percent CO2 shielding gas.
Typically, the best low alloy flux-cored wire for welding P91 and P92 chrome-moly is an AWS E91T1-B9. This type of wire offers a fast-freezing slag for out-of-position welding, along with low diffusible hydrogen levels to control cracking. It also has a very high tensile strength: approximately 126,000 psi. Not surprisingly, because P91 and P92 chrome-moly pipe are used for higher temperature services than the other grades, E91T1-B9 flux-cored wire creates X-Ray quality welds, which are essential on such critical piping applications.
The Asia's largest sugar mill in yamunanagar, Haryana in January 2010 which was peak season of production, the $850 million plant having the crushing capacity of 12,000 tons every day. Nearly 2,000 permanent and other 800 seasonal employee are depend upon the company came into the problem when their 2 big boilers collapsed suddenly & they were not having any other choice to replace boilers tubes immediately
The Purchase manager was deputed to Aesteiron Steel Pipes for a bid on six items, including chrome moly grade P22, chrome moly grade P11,P1 & P2 Pipe. With an original quote of $.5 million and a reputation for maintaining the closest mill relationships in the industry, Aesteiron Steel pipes not only won the job even hearts of thousand associates with SSM.
Aesteiron Steel Pipes worked hand in hand with the mills to reduce pricing, prompting the engineering company to continue to request more pipe. Because of these outstanding relationships, Aesteiron Steel Pipes was able to deliver within 3 days at factory.
Alloy Steel Seamless Pipes (AS) are used for high temperature and pressures applications and are used typically in critical applications. Some of the Standards & Specifications that Alloy Pipes confirm to are American Standards like ASTM A335 P1, P5, P9, and P11 & P22. Alloy Steel Seamless Pipes (AS) is commonly used by Oil & Gas, Hydrocarbon & Process industries. Alloy Steel Seamless Pipes (AS) can also be supplied with Indian Boiler Regulations Certifications (IBR).
We are also able to cater to client’s special requirements for:
However, above mentioned few additional services are subject to order size, quantity and availability of spare capacities.
Major failures have occurred in piping due to single-phase or wet-steam erosion-corrosion, resulting extensive plant downtime. Both nuclear and fossil power plants as well as petrochemical plants are susceptible to erosion-corrosion. Causes, possible corrective actions, where to look in susceptible systems, optimum nondestructive examinations and analytic techniques to predict remaining life are covered.
Significant variables include temperature of water or steam, pH, oxygen content of fluid, quality of steam, flow velocity, quality of oxide layer on inner surface of the pipe, and chemical composition of the steel pipe. Typical susceptible systems are feedwater and let-down lines in water and elbows, tees, etc., in wet steam. Other systems operating under comparable conditions also are susceptible to attack.
Factors mitigating erosion-corrosion which are under the control of the plant owner are the pH(>9.0 is best), oxygen content (50ppb), and pipe material (a 2.25Cr-1Mo steel is very resistant to single-phase erosion-corrosion while austenitics are resistant to wet steam).
Austenitic steels also have excellent resistance to erosion-corrosion. Low carbon grades are preferable because of better intergranular stress corrosion cracking (IGSCC) resistance. The candidate materials are 304L, 316L, and 347L. These materials are readily available and do not require preheat or postweld heat treatment. The disadvantages of austenitic stainless steels are that piping reanalysis is required due to a higher thermal coefficient (1.4 x carbon steel); the bimetallic welds need special attention; and susceptibility to chloride stress corrosion raises concern over the chloride contaminants in thermal insulation.
Class 3 systems usually are low temperature and pressure, often using austenitic stainless steel. The probability of attack by erosion-corrosion is minimal.
Class 2 systems, particularly the feedwater, definitely are susceptible; however, replacement with Pll or P22 materials (1 Cr-0.5/Mo or 2.25 Cr-l Mo) grossly reduces the rate of attack at low oxygen levels typical of these systems. If the pH can be raised to 9.5, the rate is reduced a factor of 100-1000 compared to pH -9.0. Obviously, carbon steel systems operating at about 200°C at velocities >18ft/sec with lower pH beca
A335 P1 High Pressure Steel Pipe Price (JFE-Japan) :USD 1700 per Ton(FOB Price)
A335 P1 High Pressure Steel Pipe Price (Tenaris-Italy) :USD 1900 per Ton(FOB Price)
A335 P1 High Pressure Steel Pipe Price (Arcelor Mittal) :USD 2000 per Ton(FOB Price)
A335 P1 High Pressure Steel Pipe Price (JSL-INDIA) :USD 1450 per Ton(FOB Price)
A335 P1 High Pressure Steel Pipe Price (MSL-INDIA) :USD 1500 per Ton(FOB Price)
A335 P1 High Pressure Steel Pipe Price (Mukat-INDIA) :USD 1350 per Ton(FOB Price)
A335 P1 High Pressure Steel Pipe Price (Welspun-INDIA) :USD 1450 per Ton(FOB Price)
A335 P1 High Pressure Steel Pipe Price (V&M-france) :USD 2100 per Ton(FOB Price)
A335 P1 High Pressure Steel Pipe Price (Nippon Sumitomo-Japan) :USD 1900 per Ton(FOB Price)
A335 P1 High Pressure Steel Pipe Price (China Make) :USD 850 per Ton(FOB Price)
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