The latest piping system involves the use of fittings, which are part of the system and ensure the integrity, reliability, and safety of the network of piping systems. Among the multiple materials available, the ones to think of are duplex and super duplex fittings, which have gained enormous popularity due to their excellent properties.

The gaskets and valves made from duplex and super duplex plates will have superior corrosion resistance, a feature that ranges of applications, including pipelines in acidic conditions, industrial valves, and heat exchangers. In this blog post, we will unravel the world of duplex and super duplex fittings, revealing their special features and assisting in your choice of which to use in different applications towards the remaining post.

Understanding Duplex Fittings

Duplex weld fittings, which are commonly found as duplex pipeline fittings, are made with duplex stainless steel grades like duplex (UNS S31803) and duplex (UNS S32750). Duplex pipe fittings manufacturers build the dual-phase microstructure containing austenite and ferrite, thus presenting the unique property of having a balance of strength and corrosion resistance. Duplex types of fittings are widely used in domains such as oil and gas, petrochemical, and marine fields, owning to favorable conditions of not being very corrosive and sufficiently strong.

  1. Duplex pipe suppliers offer a twofold strength yield of standard austenitic stainless steel fittings, making them easier to produce with much lighter weight by using thinner wall sections than usual.
  2. These materials exhibit outstanding strength against SCC (stress corrosion cracking) as well as pitting, which is why they are applicable for water containing chloride and acids.

Exploring Super Duplex Fittings

What are Duplex and Super Duplex Fittings? Which One to Use When?

It is with the advent of super duplex fittings, based off the more ductile super duplex stainless steel alloys like super duplex 2507 (UNS S32750) and super duplex F55 (UNS S32760), that the engineering of these materials take a leap to a higher level. Contrary to their DSS equivalents, these fittings depend on high corrosion resistance and mechanical strength. Super duplex plates are developed to endure excessive aggressive environments typically in offshore oil and gas operations, desalination plants, and undermining chemical processes.

  • Also super duplex fittings get a PREN (Pitting Resistance Equivalent Number) value above the level 40, which means they are more resistant to localized deterioration than other materials.
  • They excel in the corrosion resistance to the chloride kind of stress corrosion cracking (CISCC) and even have a high tensile strength that meets high-pressure and high-temperature applications, which brings them an indispensable role.

Choosing Between Duplex and Super Duplex Fittings

For the choice between the duplex and super duplex Ferrule Fittings, it is important, however, to consider several factors, including whether the line is intended for any corrosive fluid or any dynamic instance and what the specific mechanical properties of the line need to be. 

  • For this environment, the corrosive with high-stress duplex fittings are efficient and reliable in both cost and use. They compromise corrosion resistance and mechanical properties that meet the needs of most industries.
  • With corrosive settings like seawater, highly chloride conditions, or acidic medium, super Duplex Forged Fittings are widely used instead of typically used fittings. Thanks to their higher corrosion resistance, the cheeky can provide long-term integrity and, therefore, considerably reduce the risk of premature failure.
  • In applications of high temperatures and pressures, super duplex tubing is deemed useful because of its great mechanical properties and toleration toward stress corrosion cracking at high temperatures.


Recognizing the key distinctions between dualplex and super duplex fittings is vital when selecting the best fit for your pipe system. At Manifest Alloys, we pledge to give our customers only the best when it comes to duplex and super duplex fittings designed and tested to meet the strict standards of different industries.

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