Adapter Fittings

RFS Adapter is a connector that connects both ends of a connection without requiring direct compatibility. They are used to connect system equipment when no standard solution is possible (for example different threads or size reductions etc.). RFS Adapters mainly consist of steel and stainless steel material and provide instant solutions to ensure no project delays. It is mostly utilized for pipes having a wide size variation on both ends, such as big jumped size pipes. These fittings are used on oil hydraulic systems in many fields (fuel delivery, fuel power application, shipbuilding, mobile hydraulic equipment, etc).

For instance, It may be tough to connect a pipe with a male end of 1/2” and a female end of 1”. However, a 1/2” and 1” adapter can be designed and utilized to build the piping system and allow for the smooth flow.

Male x Female NPT Adapters

Adapter fittings material include carbon steel and stainless steel SS316.

The chemical composition of carbon steel (A105) is shown in the table below:

The chemical composition of stainless steel (SS316) is shown in the table below:

There are two categories of adapter fittings which are straight types and non-straight types. A straight adapter is made from cold down bars that meet ASTM requirements. In contrast, close grain forging is a process that is used to make non-straight fittings such as a 3-way tee or a 90-degree elbow. Furthermore, each material has a temperature range that it can tolerate. A stainless steel (SS316) material, for example, can resist a maximum temperature of 537⁰C (1000⁰F).

Adapter fittings are available between 1/8" to 1 2" . Sleeve has two different reading measurements, metric size (mm) and inch outer diameter ("OD). Sleeve size is available from 3mm to 50mm and 1/8" to 2" . Fitting sizes are designated by the corresponding outside diameter of the tubing for the various types of tube ends.

The standard working pressure of the fittings is up to 420 bar, with different pressures for different sizes and connections. The minimum burst pressure is four times the working pressure.

Pressure rating of fittings may vary when connected to different equipment. For example, if a fitting with a low working pressure is connected to a pipe, it will result in an overall lower system working pressure. In all cases, always consider the lowest pressure as the maximum working pressure of the system.

Pressure ratings for each adapter table are at an ambient temperature of 37⁰C (100⁰F). The pressure ratings of adapters are as per the requirements of ASME B31.3 process piping guide.

Adapters Fittings

A socket, also known as a coupling, is a straight connector that allows equal flow rate in only one direction. If the pipe diameters aren't the same , a reduction coupling is used to lower flow by connecting two pipes of different sizes. It generally has a female end and a male connection of the pipe.

On the other hand, adapters vary in size and connectivity . It may be tailored to the size of the system and the type of connection required. Male size of standard hex bush fitting threaded end connection is larger than female size. The female internal thread of the adapter might be larger than the male external thread, or both male and female threads can be the same size.

An adapter is a pipe fitting that connects two pipes. Adapter fittings are offered with threaded connections such as BSPP and NPT. The connection threads include hex nipple, plug, and male through a female adapter. The maximum pressure rating for adapter fitting is 420 Bar. The pressure ratings for the fittings are measured at a temperature of 100⁰F (37⁰C). Moreover, the pressure ratings are determined by some variables such as the temperature de-rating factor, the material of the O-ring seal, and the flow rate.

The gasket and O-ring material temperature is shown in the table below:

Adapter Fittings temperature ratings vary in accordance to the body material as per below:

Under normal system conditions, the maximum operating pressure for a stainless steel adapter fitting A is 420 Bars . When the temperature of the fitting working environment is raised to 400⁰C, the pressure lowers to 331 bars. This is determined by multiplying the working pressure (420 bar) with the de-rating factor (0.79) . Hence, the temperature of 400°C for stainless steel is incompatible with carbon steel and brass adapter fittings. The maximum temperature for these materials is 204⁰C. The temperature of 400⁰C for stainless steel is not suitable for adapter fittings of carbon steel and brass . It is only applicable up to a maximum temperature of 204⁰C .