Pipe bends, Stubends, Reducer, Elbows, Tee fabrication, Cone, Miterbends
All kind of Reducer fabrication
Reducers in Process Piping
A reducer is a kind of pipe fitting used in process piping that reduces the pipe size from a larger bore to a smaller bore (inner diameter).
A reducer allows for a change in pipe size to meet hydraulic flow requirements of the system, or to adapt to existing piping of a different size. The length of the reduction is usually equal to the average of the larger and smaller pipe diameters.
There are two main types of reducer:
- Concentric reducers
- Eccentric reducers
Reducers are usually concentric but eccentric reducers are used when required to maintain the same top-or bottom-of-pipe level.
Concentric Reducer
In Concentric Reducer the reduction of the pipe size is achieved by decreasing the diameter of the fitting at a constant rate over a specified length, maintaining symmetry around the fitting. Concentric Reducers are used to join pipe or tube sections of different diameters on the same axis. They provide an in-line conical transition between pressurized pipes of differing diameters. Thus, concentric reducers connect pipes of unequal size but have a common centerline. The same fitting can be used in reverse as an concentric expander.
Eccentric Reducer
In Eccentric Reducer the reduction of the pipe size is achieved by decreasing the diameter of the fitting at a constant rate over a specified length, maintaining one side of the fitting horizontally. An eccentric pipe reducer fitting is manufactured with the smaller outlet off center to the larger end, which allows it to align with only one side of the inlet. The same fitting can be used in reverse as an eccentric expander.
Uses of Concentric and Eccentric Reducers
In horizontal liquid piping, eccentric reducer must be installed with flat side up so that it can prevent trapping air in the piping system. As an exception, same is flat side down in piperack where same Bottom of Pipe (BOP) has to be maintained. Other exception is with control valves. A eccentric reducer with flat side down will give a more constant flow through the control valve rather than a concentric reducer or eccentric reducer with flat side up, which will give your more flow disruption and will cause problems with your control valve.
In horizontal gas / vapour / steam piping, eccentric reducer must be installed with flat side down which allows condensed water or fluid to drain at low points.
Eccentric reducers are used at the suction side of pumps to ensure air does not accumulate in the pipe. The gradual accumulation of air in a concentric reducer could result in a large bubble that could eventually cause the pump to stall or cause cavitation when drawn into the pump.
Reducers in vertical lines are generally concentric unless the layout dictates otherwise.
Stubends, Reducers, Elbows, Tee fabrication
Used in conjunction with a backing flange, a Stub End is, essentially, a short length of pipe with one flared end and one square-cut end, which is welded to a pipe of the same NPS, material grade and schedule. The combination of a Stub End and a backing flange is generally used as an alternative to a standard flange.
Stub ends are buttweld fittings that can be used (in combination with a lap joint flange) alternatively to welding neck flanges to make flanged connections.
The lap joint flange has no sealing face, only the stub end has the sealing face. The sealing face of a stub end may be plain, serrated, or grooved to allow for a ring type joint. Lap joint flanges are available in many sizes and classes; they are also suitable for elevated temperatures and pressures
Pipe bends, Reducer, Cone, Miterbends
A Miter bend is a bend that is made by cutting pipe ends at an angle and joining the pipe ends. A true miter bend is a 90-degree bend made by cutting two pipes at 45 degrees and joining them by welding. Similarly, three pipes cut at 22.5 degrees will give a 90 degree miter bend.
Miter bend are not standard pipe fittings they are fabricated from pipes. Usually, they are preferred for size 10” & above because large size elbow is expensive. Use of miter bend is restricted to the low-pressure water line. Miter bend can be fabricated in 2, 3, & 5 pieces.
