What are the inspection criteria for flanges?
The inspection criteria would depend on their type, size and intended application. However, some general criteria apply to most flanges used in industrial settings. These will ensure the quality, integrity and compatibility for the intended use. Some of the criteria are dimensional inspection, surface condition, material verification, bolt holes, pressure test, etc.
| ASME | Sizes | Types |
|---|---|---|
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| Coating | Face Types | Material |
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| Pressure Rating | DIN Pressure | Origin |
| Class 150 to Class 2500 | PN 6 to PN64 | Indian / Japan / USA / Korean |
How many types of steel flanges do we have?
There are several types of steel flanges for specific applications and requirements. Some common ones would include weld neck, slip on, blind, socket weld, orifice, lap joint and threaded flange. There are other types as well that can be used for connecting pipes in various situations.
Stainless Steel Plain Flanges
Carbon Steel Flat Flanges
Alloy Steel Weld Neck Flanges
Astm A105 Slip On Flange
Copper Nickel Blind Flange
Nickel Alloy Lap Joint Flanges
Super Duplex Orifice Flanges
Duplex Raised Face Flanges
Titanium Reducing Flanges
| Nom. Pipe Size | O | T | TJ | R | X | #/Dia of Holesa | Bolt Circle Dia | B | B2b | B3 | H | L | L2 | L3c | r | D | Thr |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ½ | 3.50 | 0.38 | 0.44 | 1.38 | 1.19 | 4-0.62 | 2.38 | 0.88 | 0.62 | 0.90 | 0.84 | 0.56 | 1.81 | 0.62 | 0.12 | 0.38 | 0.62 |
| ¾ | 3.88 | 0.44 | 0.50 | 1.69 | 1.50 | 4-0.62 | 2.75 | 1.09 | 0.82 | 1.11 | 1.05 | 0.56 | 2.00 | 0.62 | 0.12 | 0.44 | 0.62 |
| 1 | 4.25 | 0.50 | 0.56 | 2.00 | 1.94 | 4-0.62 | 3.12 | 1.36 | 1.05 | 1.38 | 1.32 | 0.62 | 2.12 | 0.69 | 0.12 | 0.50 | 0.69 |
| 1¼ | 4.62 | 0.56 | 0.62 | 2.50 | 2.31 | 4-0.62 | 3.50 | 1.70 | 1.38 | 1.72 | 1.66 | 0.75 | 2.19 | 0.81 | 0.19 | 0.56 | 0.81 |
| 1½ | 5.00 | 0.62 | 0.69 | 2.88 | 2.56 | 4-0.62 | 3.88 | 1.95 | 1.61 | 1.97 | 1.90 | 0.81 | 2.38 | 0.88 | 0.25 | 0.62 | 0.88 |
| 2 | 6.00 | 0.69 | 0.75 | 3.62 | 3.06 | 4-0.75 | 4.75 | 2.44 | 2.07 | 2.46 | 2.38 | 0.94 | 2.44 | 1.00 | 0.31 | 0.69 | 1.00 |
| 2½ | 7.00 | 0.81 | 0.88 | 4.12 | 3.56 | 4-0.75 | 5.50 | 2.94 | 2.47 | 2.97 | 2.88 | 1.06 | 2.69 | 1.12 | 0.31 | 0.75 | 1.12 |
| 3 | 7.50 | 0.88 | 0.94 | 5.00 | 4.25 | 4-0.75 | 6.00 | 3.57 | 3.07 | 3.60 | 3.50 | 1.12 | 2.69 | 1.19 | 0.38 | 0.81 | 1.19 |
| 3½ | 8.50 | 0.88 | 0.94 | 5.50 | 4.81 | 8-0.75 | 7.00 | 4.07 | 3.55 | 4.10 | 4.00 | 1.19 | 2.75 | 1.25 | 0.38 | 0.88 | 1.25 |
| 4 | 9.00 | 0.88 | 0.94 | 6.19 | 5.31 | 8-0.75 | 7.50 | 4.57 | 4.03 | 4.60 | 4.50 | 1.25 | 2.94 | 1.31 | 0.44 | 0.94 | 1.31 |
| 5 | 10.00 | 0.88 | 0.94 | 7.31 | 6.44 | 8-0.88 | 8.50 | 5.66 | 5.05 | 5.69 | 5.56 | 1.38 | 3.44 | 1.44 | 0.44 | 0.94 | 1.44 |
| 6 | 11.00 | 0.94 | 1.00 | 8.50 | 7.56 | 8-0.88 | 9.50 | 6.72 | 6.07 | 6.75 | 6.63 | 1.50 | 3.44 | 1.56 | 0.50 | 1.06 | 1.56 |
| 8 | 13.50 | 1.06 | 1.12 | 10.62 | 9.69 | 8-0.88 | 11.75 | 8.72 | 7.98 | 8.75 | 8.63 | 1.69 | 3.94 | 1.75 | 0.50 | 1.25 | 1.75 |
| 10 | 16.00 | 1.12 | 1.19 | 12.75 | 12.00 | 12-1.00 | 14.25 | 10.88 | 10.02 | 10.92 | 10.75 | 1.88 | 3.94 | 1.94 | 0.50 | 1.31 | 1.94 |
| 12 | 19.00 | 1.19 | 1.25 | 15.00 | 14.38 | 12-1.00 | 17.00 | 12.88 | 12.00 | 12.92 | 12.75 | 2.12 | 4.44 | 2.19 | 0.50 | 1.56 | 2.19 |
| 14 | 21.00 | 1.31 | 1.38 | 16.25 | 15.75 | 12-1.12 | 18.75 | 14.14 | 13.25 | 14.18 | 14.00 | 2.19 | 4.94 | 3.12 | 0.50 | 1.63 | 2.25 |
| 16 | 23.50 | 1.38 | 1.44 | 18.50 | 18.00 | 16-1.12 | 21.25 | 16.16 | 15.25 | 16.19 | 16.00 | 2.44 | 4.94 | 3.44 | 0.50 | 1.75 | 2.50 |
| 18 | 25.00 | 1.50 | 1.56 | 21.00 | 19.88 | 16-1.25 | 22.75 | 18.18 | 17.25 | 18.20 | 18.00 | 2.62 | 5.44 | 3.81 | 0.50 | 1.94 | 2.69 |
| 20 | 27.50 | 1.62 | 1.69 | 23.00 | 22.00 | 20-1.25 | 25.00 | 20.20 | 19.25 | 20.25 | 20.00 | 2.81 | 5.62 | 4.06 | 0.50 | 2.13 | 2.88 |
| 22 | 29.50 | 1.75 | 1.81 | 25.25 | 24.25 | 20-1.38 | 27.25 | 22.22 | 21.25 | 22.25 | 22.00 | 3.07 | 5.82 | 4.25 | 0.50 | 2.38 | 3.13 |
| 24 | 32.00 | 1.81 | 1.88 | 27.25 | 26.12 | 20-1.38 | 29.50 | 24.25 | 23.25 | 24.25 | 24.00 | 3.19 | 5.94 | 4.38 | 0.50 | 2.50 | 3.25 |
| Nominal Pipe Size | Threaded | Lap Joint | Socket Weld | Weld Neck | Slip On | Blind |
|---|---|---|---|---|---|---|
| ½ | 1 | 1 | 2 | 2 | 1 | 2 |
| ¾ | 2 | 2 | 2 | 2 | 2 | 2 |
| 1 | 2 | 2 | 2 | 3 | 2 | 2 |
| 1¼ | 3 | 3 | 3 | 3 | 3 | 3 |
| 1½ | 3 | 3 | 3 | 4 | 3 | 4 |
| 2 | 5 | 5 | 5 | 6 | 5 | 5 |
| 2½ | 8 | 8 | 8 | 10 | 8 | 7 |
| 3 | 9 | 9 | 9 | 11.5 | 9 | 9 |
| 3½ | 12 | 11 | 11 | 12 | 11 | 13 |
| 4 | 13 | 13 | 13 | 16.5 | 13 | 17 |
| 5 | 15 | 15 | 15 | 21 | 15 | 20 |
| 6 | 19 | 19 | 19 | 26 | 19 | 27 |
| 8 | 30 | 30 | 30 | 42 | 30 | 47 |
| 10 | 43 | 43 | 43 | 54 | 43 | 70 |
| 12 | 64 | 64 | 64 | 88 | 64 | 123 |
| 14 | 90 | 105 | 90 | 114 | 90 | 140 |
| 16 | 98 | 140 | 98 | 140 | 106 | 180 |
| 18 | 130 | 160 | 130 | 165 | 130 | 220 |
| 20 | 165 | 195 | 165 | 197 | 165 | 285 |
| 22 | 185 | 245 | 185 | 225 | 185 | 355 |
| 24 | 220 | 275 | 220 | 268 | 220 | 430 |
| Temperature (in F°) | 150# | 1500# | 300# | 900# | 600# | 400# | 2500# |
| < 100 | 285 | 3705 | 740 | 2220 | 1480 | 985 | 6170 |
| 200 | 260 | 3395 | 680 | 2035 | 1360 | 905 | 5655 |
| 300 | 230 | 3270 | 655 | 1965 | 1310 | 870 | 5450 |
| 400 | 200 | 3170 | 635 | 1900 | 1265 | 845 | 5280 |
| 500 | 170 | 3015 | 605 | 1810 | 1205 | 805 | 5025 |
| 600 | 140 | 2840 | 570 | 1705 | 1135 | 755 | 4730 |
| 650 | 125 | 2745 | 550 | 1650 | 1100 | 730 | 4575 |
| 700 | 110 | 2655 | 530 | 1590 | 1060 | 710 | 4425 |
| 750 | 95 | 2535 | 505 | 1520 | 1015 | 675 | 4230 |
| 800 | 80 | 2055 | 410 | 1235 | 825 | 550 | 3430 |
| 850 | 65 | 1595 | 320 | 955 | 640 | 425 | 2655 |
| 900 | 50 | 1150 | 230 | 690 | 460 | 305 | 1915 |
| 950 | 35 | 685 | 135 | 410 | 275 | 185 | 1145 |
| 1000 | 20 | 430 | 85 | 255 | 170 | 115 | 715 |
| Hydrostatic Test Pressure (in Psig) | 450 | 5575 | 1125 | 3350 | 2225 | 1500 | 9275 |
| Products | Price |
| ANSI 150 CLASS B16.5 S.S. 304 SLIP ON FLANGES RAISE FACE SIZE: 3 | US $13.15 per Piece |
| BLIND FLANGE RE CLASS 150 B16 5 SS A182 F316 | US $14.69 per Piece |
| Type | Pipe sizes | Pressure capacity | Use for |
| Threaded | Small | Low | Attaching without welding |
| Slip on | All | Low | Installation cost low; easy assembly |
| Lap joint | All | Low | Systems that need frequent disassembly |
| Weld neck | All | High | High-pressure systems; extreme temperatures |
| Blind | All | Very high | Flow pressure testing; closing pipes |
RTJ face
Raised face
Flat face
The flange pressure class depends on three factors:
What is the most common facing used with steel Industrial Flanges?
The most common facing used with steel industrial flanges is the Raised Face. The raised portion of the Raised face flange provides an additional contact area for the gasket. It helps to improve the seal between the flange faces when bolted together.
How do you fix a leaking Pipe Flanges?
To fix a leakage in the Pipe flange, you should start by inspecting the leakage source. Shut off the bolts and tighten them; make sure to torque the bolts correctly. If that doesn't stop the issue, you might need to replace the gasket. Check the flange for damage as it might require repair or replacement. You can use sealant if required and perform a pressure test to see the results.
What are the different coatings and surface treatments available to prevent corrosion on blind flange?
Various types of coatings can be applied on a Blind flange to protect them from damage and corrosion. Some of the common coatings would include paint, hot-dip galvanizing, electroplating, epoxy, powder, fusion bonded, ceramic, etc.
What are slip on flange used for in construction?
Slip on flange is used to connect pipes and other equipment in a piping system. They are suitable for low pressure applications. These flanges offer the required joint, are easy to install and are a cost effective solution.
Frequently asked questions
What are the two main standards of floor flange?
The Raised Face orifice flange connection is generally considered the strongest. This is due to its enhanced gasket contact and sealing area which ensures a secure and reliable joint for high pressure applications.
Which orifice flange connection is the strongest?
The two main standards for floor flanges are the ANSI B16.5 standard and the ISO 7005-1 standard. They specify the dimensions, materials and pressure ratings for the flanges used in various industrial applications.
What is the maximum rtj flange gap?
The maximum RTJ flange gap is specified by your manufacturer. You can contact Mesta Inc to know about this in detail.
What is the advantage of socket weld flange joints?
Socket weld flange has high structural integrity due to the connection, which eliminates the need for external welding. They provide better flow characteristics with smooth internal surfaces. They are suitable for applications with critical flow requirements and high pressure systems.
How are sorf flanges attached?
Sorf flanges are attached to the pipe by sliding them over the pipe end until it rests against the pipe shoulder. Then fillet welding is performed on the inside and outside of the flange to secure it in place. The raised face provides additional surface area for the gasket and ensures a tight & reliable seal in the joint.
Blind flange vs slip on flange
Blind flanges are used to seal the end of a piping system. Slip on flanges can connect pipes and create a joint for low pressure applications.
Weld neck flange vs raised face flange
A weld neck flange has a long tapered neck that provides excellent structural strength and is suitable for high pressure applications. Raised face flange has a raised sealing surface that enhances gasket contact and is used in general purpose, low pressure systems.
What is flange API vs ASME?
Flanges that conform to API standards are commonly used in the oil & gas industry. ASME flanges have a broader application range in industries including oil & gas, chemical, power, etc.
What are the threaded flange classes in ASME B16 5?
In ASME B16.5, threaded flanges are available in various pressure classes which range from Class 150 to 2500. These classes indicate the pressure rating and ability of the flange to withstand different operating pressure levels in the piping system.