Pairs of pressure "Tappings", mostly on 2 sides, directly opposite each other, are machined into the orifice flange.
The function of an Hastelloy orifice flange is to provide access to a line for metering of gases or liquids. An orifice plate is clamped between a pair of flanges when installed in a line and the whole assembly is refer to as an orifice flange union. Jack-screws within the assembly facilitate removal of the orifice plate. The orifice plate, the metering device, consists of a thin plate with a concentric, square edge, circular hole in the centre. Two pressure tap-holes are drilled in each flange to measure pressure difference through the orifice.
Hastelloy Orifice flange unions are used in conjunction with orifice meters to measure the flow of liquids and gases using tapped or socket weld style meter connections located on the outside diameter of the flanges.
Grade: Hastalloy B2, Hastalloy B3, Hastalloy C22, Hastalloy C276, Hastalloy X
|Hastelloy B||0.1||1.25||0.6||28||0.3||-||-||-||-||-||5.5||rest/bal||Mn 0.80; Si 0.70|
|Hastelloy B2||0.02||1||1||26.0-30.0||-||-||-||-||-||-||2||rest/bal||Mn 1.0, Si 0.10|
|Hastelloy X||0.1||1.5||22||9||-||0.6||-||-||-||18.5||-||rest/bal||Mn 0.6; Si 0.60|
|Grade||Tensile (ksi)||.2% Yield (ksi)||Elongation %||Hardness (HRb)|
Stainless Steel :
Grade: 304 (1.4301), 304L (1.4307), 304H (1.4948), 309 (1.4828), 309S, 310, 310S (1.4845) , 316 ( 1.4401), 316H, 316L( 1.4404 /1.4432) , 317, 317L (1.4438), 321 (1.4541), 321 H(1.4878), 347 (1.4550), 347H (1.4961), 904L (1.4539)
Grade: 2205 (1.4507)
Super Duplex Steel:
Grade: 2507 (UNS S32750) (1.4410) (UNS S32750)
Grade: Inconel 600 (2.4640), Inconel 601 (2.4851), Inconel 625 (2.4856), Inconel 718(2.4668)
Grade: Incoloy 800 (2.4958), Incoloy 800H, Incoloy 800HT
Grade: Nickel 200, Nickel 201
Grade: Monel 400 ( 2.4360), Monel K500, Monel R-405
Grade: Gr.1 (3.7025) , Gr.2 (3.7035) , Gr.3:(3.7055) , Gr.5(3.7164/65), Gr. 7(3.7235) , Gr. 11 (3.7225)
The manufacturing process of flange mainly is divided into forging, casting, cutting and rolling. .
The casting and forging flanges have advantages that the blanks of them have accurate shape, size and low costs and only need simple process. But forging flanges have manufacturing defects such as blowholes, cracks, etc and have not very smooth internal organization streamline. The obvious advantages of forging flanges are that they can be forged in various shapes and they have low costs. .
Forging flanges generally have lower carbon content than the casting flanges and are not easy to rust. They have smooth streamline, uniform internal organization, and better mechanical performance than that of casting flanges. There are no defects, such as blowholes and cracks existing in the casting flanges. Forging flanges are able to withstand higher shear and drawing forces than casting flanges. However, if adopting improper forging process, it will also cause appearance of large, uneven grains and solidification cracking phenomenon, resulting in higher cost than the casting flanges. .
We can distinguish between the casting flanges and forging flanges from the different production process. To take the centrifugal flange as an example, it is a kind of casting flange. Centrifugal flanges are produced by a precision casting method, which makes the flanges’ organization smaller than those commonly produced by sand casting and improves the quality of flanges, making fewer occurrences of loose tissue, pore, sand hole etc.
Cutting process refers to producing flanges by directly cutting a round plate with the inner diameter, outer diameter and thickness which can be further processed later from the middle plate, and then processing the bolt hole and waterline. The maximum diameter of such flanges is limited by the width of the middle plate.
Cutting process refers to producing flanges by cutting stripes from the middle plate and then rolling them into round shape. This process is mainly used for the production of large flange. After the rolling process, weld and then flatten the round shape, and finally process the serrated spiral finish and bolt hole.