Orifice fittings are commonly used in fluid flow measurement applications to create a constriction in the flow path, allowing for differential pressure measurement across the orifice plate. There are several types of orifice fittings based on their design and installation method. Here are some common types:

1. Flange Orifice Fitting:

   • Flange orifice fittings consist of two flanges with an orifice plate sandwiched between them. The orifice plate is installed concentrically in the flow line using gaskets and bolts.
   • This type of orifice fitting allows for easy installation and removal of the orifice plate for inspection, maintenance, or replacement.

2. Weld Neck Orifice Fitting:

   • Weld neck orifice fittings have a welded neck flange on one end and a raised face flange on the other end. The orifice plate is welded into the flow line using the weld neck flange.
   • This type of orifice fitting provides a permanent and leak-proof installation but requires welding for installation and removal of the orifice plate.

3. Threaded Orifice Fitting:

   • Threaded orifice fittings have threaded connections on both ends, allowing for easy installation into threaded piping systems.
   • This type of orifice fitting is commonly used in smaller pipe sizes and low-pressure applications where welding or flange connections are not practical.

4. Slip-On Orifice Fitting:

   • Slip-on orifice fittings consist of two slip-on flanges with an orifice plate sandwiched between them. The orifice plate is inserted into the flow line and held in place by the slip-on flanges.
   • This type of orifice fitting provides a semi-permanent installation and allows for easy removal and replacement of the orifice plate without disturbing the piping connections.

5. Clamp-On Orifice Fitting:

   • Clamp-on orifice fittings use clamping mechanisms to attach the orifice plate to the pipe without the need for welding or threading.
   • This type of orifice fitting is often used for temporary flow measurement applications or in situations where drilling into the pipe is not feasible.

6. Ring Type Orifice Fitting:

   • Ring type orifice fittings consist of a single-piece machined ring with an orifice bore, which is inserted between flanges in the flow line.
   • This type of orifice fitting provides a compact and lightweight design and is commonly used in small pipe sizes or applications with space constraints.

These are some common types of orifice fittings used in fluid flow measurement applications. The selection of the appropriate type depends on factors such as pipe size, pressure rating, fluid properties, installation method, and maintenance requirements.