|
|
|
This group of flanges is designed with a hub on the backside tapering to a diameter that will match the pipe to which it will be welded. These flanges are bored to match the inside diameter of the mating pipe so there will be no restriction of product flow. This prevents turbulence at the joint and reduces erosion. Welding neck flanges are preferred for use in severe service applications involving high pressure, sub-zero and/or elevated temperatures. They also provide excellent stress distribution through the tapered hub and are easily radiographed for flaw detection. |
Used in conjunction with a "Lap Joint Stub End," these flanges are nearly identical to a slip-on flange with the exception of a radius at the intersection of the flange face and the bore to accommodate the flanged portion of the stub end. These flanges are used in applications where the joint must be frequently disassembled for cleaning or where there is a need to facilitate bolt alignment. |
|
|
|
These flanges are similar to slip-on flanges except they have a bore diameter equal to that of the matching pipe. They also have a counterbore from the hub side slightly larger than the outside diameter of the matching pipe. The counterbore provides a "socket" into which the end of the pipe is inserted. The flange is then attached to the pipe by a fillet weld at the hub. The shoulder made by the difference between the bore and counterbore is the same width as the wall of the pipe, thereby providing for an unrestricted flow of product through the connection. These flanges were initially developed for use in small diameter, high- pressure lines. Internally welded socket type flanges are typically used in chemical processes, hydraulic lines and steam distribution lines. |
Slip-on flanges are designed to slide over the outside diameter of the pipe to which it will be welded. These flanges are attached to the pipe by fillet welding at the hub and at the end of the pipe inside the flange. Because of the low hub and method of attachment, these flanges are not normally used in high stress applications. |
|
|
|
Threaded flanges are
threaded in the bore to match an external thread on the
pipe. The threads are tapered to create a seal between
the flange and pipe as the tapers approach the same
diameter. These flanges are normally designed for low
pressure, non-cyclic applications. They are also used in
applications where |
BLIND FLANGES These flanges are manufactured without a bore and used as closures or seals for the ends of piping systems. They are also used to provide access covers for pressure vessels. Blind flanges are provided with or without a hub, depending on customer requirements. Under pressure and bolt loading, the blind flange is subjected to more stresses than any other flange type. However, the maximum stresses are bending stresses at the center and are easily absorbed by the flange. |
ORIFICE FLANGES Designed for flow metering systems. Two of these flanges with bolts and jack screws are called an "orifice flange union" and are used in conjunction with an "orifice plate." The orifice plate is a separate commodity and is not sold as a part of the flange assembly. Each flange is provided with a pair of pressure taps for measurement of pressure drop in the flow through the orifice plate. The taps are precisely located with respect to the orifice plate. Orifice flanges may be provided in one of three types of flanges: Welding Neck, Slip-On and Threaded. |
REDUCING FLANGES Designed for use in
changing diameters in a piping system. A reducing flange
consists of a flange with one specified diameter having a
bore of a different and smaller, diameter. Except for the
bore and hub dimensions, the flange will have dimensions
of the larger pipe size. Reducing flanges are normally
provided as one of three types: Welding Neck, |
|
Copyright © 1997. Boltex Manufacturing, Inc. All rights Reserved
