High‑Quality Forged Threaded Flanges Carbon / Alloy Steel, Custom & Non‑Standard Sizes Available

Description

1. Introduction to Forged Threaded Flanges

Threaded flanges (also called screwed flanges) are widely used in fire protection, gas, chemical, instrumentation piping, and other applications because they require no welding and are easy to install. As a professional forged flange manufacturer, we often receive various inquiries about threaded flanges. This article compiles the most common questions into an FAQ to help you select the right product quickly and avoid common mistakes.

2. Applications of Forged Threaded Flanges

• Oil & Gas Industry – wellhead pipelines, oil/gas transmission branch lines, high-pressure gathering lines, small wellhead fittings.
• Chemical & Refining – lines carrying flammable/explosive media, process piping where hot‑work welding is not permitted.
• Municipal Fire Protection – high‑pressure fire‑fighting piping, gas pipelines.
• Pressure Vessels & Pump/Valve Auxiliaries – pump suction/discharge connections, small high‑pressure vessel nozzles, valve flange interfaces.

• Power Industry – auxiliary high‑pressure water and oil lines in power plants.
• Marine Engineering – small‑/medium‑bore high‑pressure lines on offshore platforms.
• Mechanical Hydraulics – high‑pressure hydraulic oil circuits, test equipment piping.

3. Common Materials for Forged Threaded Flanges

Carbon Steel Series – A105, 20#, Q235B, 16Mn.

Alloy Steel Series – 4130 (30CrMo), 4140 (42CrMo), 15CrMo, Cr5Mo.

4. Advantages of Forged Threaded Flanges

1. No welding required – directly screwed onto the pipe, eliminating the need for hot work on site; suitable for explosion‑proof areas and no‑welding zones.
2. High strength and excellent pressure‑bearing capacity – integrally forged with dense grain structure and few internal defects; much more reliable than cast flanges under high‑pressure conditions.
3. Easy disassembly – convenient for later maintenance and inspection; pipelines can be quickly separated.
4. Fast installation – saves welding and NDT (non‑destructive testing) steps, shortening the on‑site construction period.
5. Suitable for high temperature and high pressure – forged materials offer superior mechanical properties and can be used in higher pressure ratings.
6. Controllable sealing – with matching gaskets, the flange face can be tightened to achieve reliable sealing.
7. Flexible material selection – available in carbon steel, alloy steel, and stainless steel to suit corrosive, low‑temperature, high‑temperature, and various other service conditions.

5. Types of Forged Threaded Flanges We Can Produce

• Threaded neck flanges (high‑hub threaded flanges)
• Flat threaded flanges (raised‑face threaded flanges)
• Threaded blind flanges (threaded blanking flanges)
• Large‑diameter heavy‑duty threaded flanges
• High‑pressure wellhead‑specific threaded flanges
• Non‑standard custom‑shaped threaded flanges
• Flanges with special threads: NPT, API threads, etc.

6. Standards and Sizes We Manufacture

GB/T 9114

HG/T 20592 / 20635 (European and American standard systems)

American standards: ASME B16.5, ASME B16.47

Petroleum industry: API 6A, SY/T 5037

7. How to Choose the Right Threaded Flange – Key Selection Points

1. Determine pipe parameters – pipe size (DN/NPS), wall thickness, and external thread specification of the pipe.
2. Determine service conditions – medium (oil, gas, water, corrosive fluids), working pressure, and working temperature.
3. Select the pressure rating – the flange pressure rating must be ≥ the maximum working pressure of the piping system.
4. Select the material – match carbon steel / alloy steel / stainless steel according to temperature and corrosion resistance requirements.
5. Confirm the thread type – verify whether the pipe external thread is NPT, BSP, or metric, and ensure the flange thread matches exactly.
6. Choose the flange facing type – RF, RJ, FM/M, etc., to match the mating flange and gasket.
7. Confirm the applicable standard – ASME, HG, GB, GOST, etc.