Technical Blog — Page 2

A hot tap (also called a live tap, line tap, or pressure tap) is a connection made onto a pressurised, in-service pipeline or piping system without…

Liquid sulphur is produced in large quantities from Claus sulphur recovery units in oil refineries and gas processing plants. It must be transported and…

Buttweld pipe fittings for high-pressure gas and liquid pipelines — cross-country transmission lines, offshore pipelines, and high-pressure gathering…

Microalloying — the addition of small quantities (0.02–0.15 wt%) of niobium, vanadium, or titanium to carbon steel — is the metallurgical basis for…

Heat treatment of carbon and alloy steel pipe fittings is not a single operation — it is a family of distinct thermal processes that produce different…

The Haber-Bosch synthesis loop operates at 150–220 bar and 400–550°C with a hydrogen-rich gas mixture. This combination creates two simultaneous material…

High-temperature hydrogen attack (HTHA) is a degradation mechanism in carbon and low-alloy steel exposed to hydrogen gas at elevated temperature and…

The bolts and nuts in a flanged pipe fitting connection are often the weakest link at elevated temperature. While the flange and fitting may be correctly…

In high-temperature refinery service — hydrotreater furnace outlets, hydrocracker hot separators, atmospheric and vacuum distillation transfer lines — two…

Hydrogen-induced cold cracking (HICC) — also called delayed cracking or hydrogen-assisted cracking — is the most common weld failure mode in CrMo alloy…

Hydrogen embrittlement (HE) is the loss of ductility and fracture toughness in steel when atomic hydrogen is absorbed into the metal lattice. Unlike most…

Incoloy 800, 800H, and 800HT are three variants of the same base Fe-Ni-Cr alloy (EN 1.4876 / ASTM B366 grade family) that are frequently specified…

Galvanic corrosion occurs when two dissimilar metals are in electrical contact in the presence of an electrolyte — the less noble (more anodic) metal…

Both 347H (Nb-stabilised) and 321H (Ti-stabilised) resist sensitisation and provide high-temperature creep strength. The reason 347H is often preferred…

Sensitisation is a microstructural change in austenitic stainless steel that renders it susceptible to intergranular corrosion (IGC) — preferential attack…

Specifying the wrong stainless steel grade often results from conflating two distinct failure modes: intergranular corrosion (IGC) — caused by chromium…

The duplex stainless steel family is not limited to the well-known 2205 grade. Two leaner alloys — LDX 2101 (EN 1.4162, S32101) and 2304 (EN 1.4362…

Stainless steel and nickel alloy pipe fittings arrive at site with a passive surface that has been carefully maintained since final inspection. Inadequate…

Most pipe fitting engineers never need to think about magnetic permeability — but in a small number of specialist applications, ferromagnetism in fittings…

The Hastelloy B-family (Ni-Mo alloys without significant chromium) represents the highest resistance to reducing acids — hydrochloric acid, sulphuric acid…

Hastelloy G-30 (UNS N06030) is a nickel alloy specifically developed for the wet-process phosphoric acid (WPA) environment — one of the most corrosive…

Solid Inconel 625 buttweld fittings cost 18–25× the price of carbon steel equivalents — a significant cost premium that is fully justified when the entire…

Deepwater sour gas production combines three challenges simultaneously: high H₂S partial pressure (NACE sour service), elevated chloride concentration from…

Inconel 690 (29–31% Cr, 58% Ni, 9% Fe, C ≤0.05%) was developed specifically to address the PWSCC failures of Alloy 600 in PWR steam generator tubing from…

Monel 400 (UNS N04400, EN 2.4360) is the standard Ni-Cu alloy for HF alkylation, seawater, and sour gas service — but its yield strength of approximately…

Nickel alloy filler metals are not interchangeable with carbon or stainless steel fillers — and in many cases they are not interchangeable with each other…

Nickel alloys used for pipe fittings — Inconel 625, Hastelloy C-276, Alloy 825 — solidify from the melt with significant dendritic microsegregation. The…

High-nickel alloys are well known for their resistance to chloride stress corrosion cracking — a property that makes them the material of choice for…

The terms "forged" and "wrought" are sometimes used interchangeably for pipe fittings, but they describe different manufacturing routes with different…

When H₂S is present in a wet gas or liquid stream, three distinct hydrogen damage mechanisms can act on carbon and low-alloy steel pipe fittings. They are…

Hydrostatic testing of the completed piping system — as distinct from factory testing of individual fittings — is governed by the piping system code (ASME…

Pressure testing is the final integrity verification for a pipe fitting assembly before commissioning — it demonstrates that the system can sustain…

Ferritic steels (carbon steel, low-alloy CrMo) undergo a ductile-to-brittle transition as temperature decreases — below the ductile-to-brittle transition…

An Inspection and Test Plan (ITP) is a document that defines, for each stage of pipe fitting manufacture and inspection, what activity is performed, what…

Liquid penetrant testing (PT) and magnetic particle testing (MT) are both surface examination methods used to detect open surface discontinuities on pipe…

Manganese sulphide (MnS) inclusions are an inherent feature of conventional carbon steel produced without specific sulphur control. These elongated…

An EN 10204 material test certificate is not just a document — it is the legal and technical proof that the fitting in your hand was manufactured from the…

Carbon steel is a ductile material at ambient and elevated temperature, but undergoes a transition to brittle behaviour at low temperatures — the…

Every pipe fitting connected to a pressure vessel, heat exchanger, pump, or compressor nozzle imposes loads on that nozzle from the piping system — forces…

Nuclear power plant piping systems are classified into safety classes (Class 1, 2, and 3 under ASME Boiler and Pressure Vessel Code Section III) based on…