Plate Flanges

Understanding your choice of plate flanges options

Choosing the right plate flange is critical to ensuring the proper operation of your piping system. With so many options available, deciding which type of plate flange is best for your needs can be overwhelming. Guanxin will guide you through the different types of plate flanges and help you understand your options.

What are plate flanges?

Plate flanges, also known as flat welded flanges, are used to connect steel piping to steam pipe flanges. A plate flange is a circular disc used to create a secure connection between two pipes or between a pipe and a valve or other device. The rated pressure does not exceed 2.5 MPa. the topology of the plate flange consists of a single-sided weld. It is connected with a double-sided nut, and only one side is welded during welding, eliminating the need to weld pipe bores or flange connections. It is typically used for low and medium-pressure pipelines.

Features of plate flange

Plate flanges not only save space and reduce weight, but more importantly, ensure that the joint area will not leak and has good sealing performance. The reason for the reduced size of the compact flange is the reduced diameter of the seal, which will reduce the cross section of the sealing surface. Secondly, the flange gasket has been replaced by a sealing ring to ensure that the sealing surface matches the sealing surface. In this way, only a small amount of pressure is required in order to press the seal tight. As the required pressure decreases, the size of the bolts and the number of bolts required can be reduced accordingly, so that a new product with small size and light weight (70-80% less than the weight of conventional flanges) is finally designed. Therefore, plate flange type a relatively high-quality flange products, reduce the quality and space, for industrial use plays an important role.

The sealing principle of plate flange

The two sealing surfaces of the bolt squeeze each other flange gasket and form a seal, but this also leads to the destruction of the seal. In order to maintain the seal, a large bolt force has to be maintained, and for this reason, the bolt has to be made larger. Larger bolts have to be matched with larger nuts, which means that larger diameter bolts are needed to create the conditions for tightening the nuts. However, the larger the diameter of the bolt, the more the applicable flange becomes bent, and the only way to do this is to increase the wall thickness of the flange section. The entire installation would require great size and weight, which becomes a particular problem in offshore environments where weight is always a major concern. Moreover, fundamentally, a flat weld flange is an ineffective seal that requires 50% of the bolt load to be used to squeeze the gasket, leaving only 50% of the load to hold pressure.

Plate flanges provide a strong, leak-free connection and are available in different types, sizes, and materials. Each type of plate flange has unique features that make them suitable for specific applications. Different plate flanges include slip-on plate flanges, blind plate flanges, angle face ring plate flanges, lap joint plate flanges, socket weld plate flanges, and studding outlet plate flanges.

Types of Plate Flanges

Slip-On Plate Flange:

A slip-on plate flange is a standard plate flange with a raised face that fits over the pipe end. The flange is then welded to the pipe, creating a strong, leak-proof joint. Slip-on plate flanges are easy to install and are commonly used in low-pressure applications.

Blind Plate Flange:

A blind plate flange is a standard plate flange with a raised face but no inside diameter. It is used to close the end of a pipe or vessel and is bolted to the flange using blind bolts. Blind plate flanges are commonly used in high-pressure applications and when the pipe needs to be blocked for maintenance or repair.

Angle Face Ring Plate Flange:

An angle face ring plate flange is a standard plate flange with a raised face and inside diameter chamfer. The chamfer provides a secure seat for the gasket and prevents it from being blown out by high-pressure flow. Angle face ring plate flanges are commonly used in high-pressure applications requiring a secure seal.

Lap Joint Plate Flange:

A lap joint plate flange is similar to the angle face ring plate flange but has a radius on the inside diameter instead of a chamfer. The lap joint plate flange is used in applications requiring easy alignment, such as in systems with thermal expansion or where pipes need to be rotated.

Socket Weld Plate Flange:

A socket weld plate flange is a standard plate flange with a raised face on the top and bottom and an inside diameter counterbore. The counterbore allows the pipe to be inserted, and the flange is then welded to the pipe, creating a solid and leak-proof joint. Socket weld plate flanges are commonly used in high-temperature and high-pressure applications.

Studding Outlet Plate Flange:

A studding outlet plate flange is a standard plate flange with a raised face and blind, drilled, and tapped holes. The flange is used in applications requiring a branch connection, and the pipe size is smaller than the main pipe. The holes are drilled and tapped to allow for the installation of a studded outlet.

Standard for Plate flanges

This standard provides the dimensions, material requirements, and testing procedures for plate flanges used in pressure piping systems. It also provides the standards for flange facings, gaskets, and bolting for use with these flanges.

Materials of Plate flanges

Depending on the specific application requirements, plate flanges are made from a variety of metal materials, including:

Sizes for Plate flanges

Plate flanges are available in different sizes, ranging from 1/2 inch to 24 inches. The size of the plate flange is determined by the size of the pipe to which it will be connected. The most common sizes of plate flanges are 2-inch, 3-inch, 4-inch, 6-inch, 8-inch, 10-inch, 12-inch, and 14-inch. Each size has its own unique features and applications.

Dimensions of Plate flanges

The dimensions of plate flanges, including the flange size, pressure rating, bolt circle diameter, and the number and size of bolt holes.

• The diameter of a plate flange is specified as the outside diameter of the flange. This diameter is typically larger than the diameter of the pipe being connected. The thickness of the flange is also specified, and it varies depending on the pressure rating of the flange.
• The bolt hole size is specified as the diameter of the bolt holes around the perimeter of the flange. The number of bolt holes and their spacing is also specified.
• The raised face dimensions are specified as the height of the raised face and the width of the contact surface. The raised face provides a surface for the gasket to seal against, and the contact surface’s width determines the gasket’s width that can be used.

Dimensions of ANSI B16.5 plate flanges

Dimensions of ANSI/ASME B16.5 class 150 Plate Flanges

Dimensions of ANSI/ASME B16.5 Class 300 Plate Flanges

Dimensions of ANSI/ASME B16.5 Class 600 Plate Flanges

JIS Plate Flange Dimensions

JIS 5K Plate Flange Dimensions

JIS 10K Plate Flange Dimensions

JIS 16K Plate Flange Dimensions

JIS 20K Plate Flange Dimensions

Dimensions of EN 1092-1 Type 01 Plate Flange

Dimensions of EN 1092-1 Type 01 Plate Flange PN6

PN 6 plate flange dimensions (EN 1092-1 type 01) with stud metric bolts and nuts requirements.
Sizes in millimeters

Dimensions of EN 1092-1 Type 01 Plate Flange PN10

PN 10 plate flange dimensions (EN 1092-1 type 01) with stud metric bolts and nuts requirements.
Sizes in millimeters

Dimensions of EN 1092-1 Type 01 Plate Flange PN16

PN 16 plate flange dimensions (EN 1092-1 type 01) with stud metric bolts and nuts requirements.
Sizes in millimeters

Dimensions of EN 1092-1 Type 01 Plate Flange PN23

PN 25 plate flange dimensions (EN 1092-1 type 01) with stud metric bolts and nuts requirements.
Sizes in millimeters