Seamless Steel Pipe

Mannesmann plug mill process
In the Plug Mill Process, a solid round (billet) is used. It is uniformly heated in the rotary hearth heating furnace and then pierced by a Mannesmann piercer. The pierced billet or hollow shell is rollreduced in outside diameter and wall thickness. The rolled tube simultaneously burnished inside and outside by a reeling machine. The reeled tube is then sized by a sizing mill to the specified dimensions. From this step the tube goes through the straightener. This process completes the hot working of the tube. The tube (referred to as a mother tube) after finishing and inspection, becomes a finished product.

• Application: For High Temperature Fluids Transmission (oil, gas, water, steam etc.)
• Specification:
• OD: 1/8" - 48" (10.3 - 1219mm)
• WT: SCH 10 - 160, SCH STD, SCH XS, SCH XXS
• LENGTH: Fixed Length (5.8/6/11.8/12mtr), SRL, DRL
• Standard & Grade: ASTM A106, Grade A/B/C
• Ends: Square Ends/Plain Ends (straight cut, saw cut, torch cut), Beveled/Threaded Ends
• Surface: Bare, Lightly Oiled, Black/Red/Yellow Painting, Zinc/Anti-corrosive Coating
• Packing: Bundled/In Bulk, Plastic Caps Plugged, Waterproof Paper Wrapped

This specification covers wall seamless and welded carbon and alloy steel pipe intended for use at low temperatures. The pipe shall be made by the seamless or welding process with the addition of no filler metal in the welding operation. All seamless and welded pipes shall be treated to control their micro-structure. Tensile tests, impact tests, hydro-static tests, and nondestructive electric tests shall be made in accordance to specified requirements.
Scope

1. This specification covers nominal (average) wall seamless and welded carbon and alloy steel pipe intended for use at low temperatures. Several grades of ferric steel are included as listed in Table 1. Some product sizes may not be available under this specification because heavier wall thicknesses have an adverse affect on low-temperature impact properties.
2. Supplementary Requirement S1 of an optional nature is provided. This shall apply only when specified by the purchaser.
3. The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in non-conformance with the specification. The inch-pound units shall apply unless the "M" designation of this specification is specified in the order.

1. The greatest advantage of seamless steel pipes is their increased ability to withstand pressure. The weakest point in a welded steel pipe is the welded seam. But because a seamless steel pipe has not been welded, it doesn`t have that seam, making it equally strong around the entire circumference of the pipe.
2. Because welded seam pipe is wrapped around another form before it is welded, and because welding adds heat, stress and other extraneous variables to the forming process, it can never be as round as seamless steel pipe.
3. Seamless steel pipe can sometimes be more expensive than other forms of steel pipe, but it`s also more reliable.