Marzogh logo


free consultation

Working hours: 08:30 am to 13:00 pm and 14:00 pm to 17:30 pm

Iraq- baghdad

kradeh inside, near babel, hotel Jamrh complex, 3rd floor




Flanges are used to connect valves and fittings to pipes. There are different kinds of flanges based on the type, the type of the flange face, and the class.

1. Flange types

Weld neck Flange

Weld neck flanges is distinguished by its long tapered hub and gradual transition of thickness in the region of the butt weld joining. Weld neck flange is used in the critical applications. It is welded at their necks. It means that the integrity of the butt-welded area can be examined by X-ray. The bores of both pipe and flange match together, so that the turbulence and erosion is decreased.

Socket Flange

A socket flange is bored to catch the pipe, and then fillet is welded. The bore of both the pipe and the flange are the same to make good flows.

Slip-on Flange

Slip-on flanges are used extremely due to their lower initial cost. They are easier to fix than a weld-neck type, because the pipe does not need such accurate cutting. A slip- on flange is slipped over the pipe, and then fillet is welded.

Screwed Flange

A screwed (or threaded flange) needs no welding. It is used to connect other threaded components in the low pressure non-critical applications.

Lap joint Flange

Lap joint flanges (or backing flanges) are used with a stub end. It is butt-welded to the pipe with the lap flange acting behind it. So, the stub end always provides the sealing face. This type of joint is mostly preferred in low pressure applications. To reduce the costs, lap flanges can be made of lower grade of material like carbon, low alloy-steel, and stainless steel in the piping system.

Blind Flange

Blind flanges (or blanking flanges) are used to close off the ends of piping, nozzles or valves. Due to internal pressure acting to bend blind flanges at their center, they are the most highly stressed of the flange types.

Orifice Flange

Orifice flanges are used to measure the flow rate of liquids and gases within a pipeline. The orifice flange consists of two flanges with an additional tapped hole in each, so that monitoring equipment, an orifice plate and jacking bolts can be attached. These facilitate the separation of flanges when they need to be inspected.

2. Flange facing

The main variables in flange facings are the profile of the flange face, the smoothness of the face, and whether a gasket is used or not.

Raised face

Raised face is a most common type used. The face is raised 1.6 mm for Class 150 and Class 300 flanges, and 6.5 mm for other classes. A flat gasket is used with this face type.

Flat face

The flat face is mostly used for non-steel flanges such as cast iron or plastic. In this type, the gasket has the same outside diameter as the flange.

Ring joint

Ring joint facing is mostly used for high-pressure and high-temperature services. Both flanges of the pair are alike, and there is a groove in each face. Oval or octagonal ring type gaskets are used in this type of facing.

Lap joint

The combination of the lap joint flange with the lap joint stub end creates a joint facing similar to that of a raised face flange.

Male and female

There are two types of male and female facings: a large male–female contact area, and a small male–female contact area

The large male–female contact area is mostly used with metal gaskets, and the small male–female contact is not suitable to be used with screwed fittings.

Tongue and groove

Tongue and groove fittings are designed to match each other. They are similar to male and female fittings, but the grooves do not extend into the flange base. Tongue and groove fittings are available in all nominal sizes.

3. Class rating

Flanges are given a class rating that refers to service pressure and temperature. The class of flange may be: 150, 300, 400, 600, 900, 1500, and 2500.


With the above explanations, we have completely realized that the pipes in different dimensions and materials depend on the kind of executive projects. But the significant point is that Marzogh Company has more than one design project and the implementation of mini-petrochemical and petrochemical in Iraq and Iran and an ongoing project in Afghanistan. Marzogh Company does not apply any ordinary material. If you use the ordinary material, you will definitely observe the lack of quality of equipment in the production process. Marzogh Company possesses a specialized board in connection and piping. It is the provider of the main parts of the popular and valid brands in the world at a reasonable price. It gives the opportunity for its customers to choose high-quality products in petrochemical parts and equipment in the production for many years. Stay tuned.


1 Response

  • Wow, awesome weblog layout! How lengthy have you been running
    a blog for? you made running a blog look easy. The entire look of your site is great, let alone the content!
    You can see similar here sklep

Leave an answer

Your email address will not be published.

Last articles
Last comments
  • Wow, awesome weblog layout! How lengthy have you been running a blog for? you made running a blog look easy. The entire look of your site is great, let alone the content! You can see similar here sklep