Ring Type Joint · RTJ Flanges · High-Pressure · Saudi Arabia · Class 600–2500

RTJ Flanges — Ring Type Joint Weld Neck Flanges for High-Pressure Aramco Piping

ASME B16.5 Class 600–2500 · ASTM A105 & A182 · EN 10204 3.1 MTCs · SAEP-347 Compatible

Gulf Union Ozone supplies Ring Type Joint (RTJ) weld neck flanges for high-pressure Saudi Aramco piping systems — Class 600 through Class 2500, in ASTM A105 carbon steel and ASTM A182 F316L stainless steel. RTJ flanges use a metal ring gasket seated in a machined trapezoidal groove to achieve a gas-tight seal under extreme pressure and temperature. All flanges shipped with EN 10204 Type 3.1 MTCs for SAEP-347 project documentation.

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Ring type joint RTJ weld neck flanges Class 900 1500 2500 Saudi Arabia — Gulf Union Ozone Jeddah
FacingRing Type Joint (RTJ)
TypeWeld Neck (WNRTJ)
Pressure Class600 · 900 · 1500 · 2500
MaterialASTM A105 · A182 F316L
StandardASME B16.5 / B16.20
MTCEN 10204 3.1
Technical Overview

What Is an RTJ Flange? — Ring Type Joint Explained for Aramco Projects

A Ring Type Joint (RTJ) flange differs from a standard raised-face (RF) flange in the sealing mechanism. Instead of a flat gasket between two raised face surfaces, the RTJ flange has a precisely machined trapezoidal groove on each face. A solid metal ring gasket (oval or octagonal cross-section per ASME B16.20) is seated in the groove, and as the flange bolts are torqued, the ring is compressed into the groove to form a metal-to-metal pressure seal.

The RTJ sealing mechanism is used in Saudi Aramco high-pressure piping where:

  • Operating pressure is high (typically Class 600 and above)
  • Temperature cycling would cause RF gaskets to leak
  • Gas tightness is critical — no permissible leak rate
  • Sour service (H₂S present) demands a positive metal seal
  • Subsea or buried service where re-tightening is impractical
RTJ vs Raised Face — When to Specify RTJ
Factor Raised Face RTJ
Pressure Class150–2500600–2500 preferred
SealingSoft/semi-metallic gasketMetal ring (A193/SS316)
Sour service H₂SAcceptable <Class 600Preferred ≥Class 600
Re-use of gasketNot recommendedNever — replace per opening
Ring Gasket Types (ASME B16.20)
Oval Ring (R-series)
Circular cross-section. Line contact at groove. Suitable for Class 600–1500. Allows minor angular misalignment during make-up.
Octagonal Ring (RX/BX-series)
Flat-sided cross-section. Full face contact — higher seating stress. Recommended for Class 900–2500. Cannot be interchanged with oval grooves. Standard for high-pressure Aramco service.
Ring Gasket Materials
Material Hardness Application
Soft IronHB 90 maxA105 CS flanges, general service
Low Carbon SteelHB 120 maxSteam, higher temperature CS service
316 SSHB 160 maxCorrosive, offshore, F316L flanges

Ring gasket hardness must be ≤ flange groove hardness (ASME B16.20).

SAEP-347 Compatibility

RTJ flanges in ASTM A105 and A182 F316L are SAEP-347 Annex 4 compatible. All Gulf Union Ozone RTJ flanges supplied with EN 10204 3.1 MTCs.

View SAEP-347 material numbers →
Stock Range

RTJ Weld Neck Flanges — Stock Range at Jeddah

Gulf Union Ozone maintains RTJ weld neck flanges in Class 600 to 2500 from its Jeddah warehouse. Custom or large-bore sizes available on inquiry with 6–12 week lead time.

Material Grade Pressure Class Size Range Ring Type In Stock
Carbon Steel ASTM A105 600 · 900 · 1500 ½″ – 24″ NPS Oval (R) & Octagonal ✓ Jeddah
Carbon Steel HP ASTM A105 2500 ½″ – 12″ NPS Octagonal only ✓ Jeddah
Stainless Steel ASTM A182 F316L 600 · 900 · 1500 ½″ – 20″ NPS Oval (R) & Octagonal ✓ Jeddah
Alloy Steel ASTM A182 F11 / F22 600 · 900 · 1500 ½″ – 16″ NPS Octagonal Inquiry

All RTJ flanges: ASME B16.5 · EN 10204 3.1 MTCs · SAEP-347 compatible · Ring gaskets available separately · Request quote →

FAQ

RTJ Flange Questions — Answered

What is an RTJ flange and when is it used for Aramco projects?

RTJ (Ring Type Joint) flanges have a machined trapezoidal groove on the face that seats a soft metal ring gasket to achieve a high-integrity pressure seal. They are specified for Saudi Aramco high-pressure piping — typically Class 600 and above — in applications handling high-pressure gas, steam, or sour hydrocarbons (H₂S). The metal-to-metal ring contact creates a leak-free joint resistant to temperature cycling and vibration. RTJ flanges are mandatory in many Aramco process piping classes for sour service and offshore applications.

What is the difference between oval and octagonal RTJ ring gaskets?

Oval RTJ rings (circular cross-section) contact the groove at two lines — allowing minor angular misalignment during make-up. Octagonal RTJ rings (flat-sided cross-section) provide full face contact with higher seating stress — recommended for Class 900+ and sour service. Octagonal rings are the standard for high-pressure Aramco service. Per ASME B16.20, oval and octagonal rings are not interchangeable between differently grooved flanges — always verify the groove profile when ordering replacement rings.

What materials are RTJ flanges made from for Aramco service?

RTJ weld neck flanges for Saudi Aramco projects are most commonly in ASTM A105 (carbon steel) and ASTM A182 F316L (316L stainless, for corrosive or marine service). Alloy grades F11 and F22 are used for high-temperature elevated pressure refinery piping. Ring gaskets (supplied separately) are in soft iron, low-carbon steel, or 316 SS — gasket hardness must be below the flange groove hardness per ASME B16.20. All flanges supplied with EN 10204 3.1 MTCs. Sour service material guide →
Related Pages
All Flanges → ASTM A105 Carbon Steel Flanges → ASTM A182 Stainless Alloy Flanges → NACE MR0175 Sour Service → SAEP-347 Material Numbers → Carbon Steel Flanges Guide →
RTJ Flanges · Ring Type Joint · Class 600–2500 · ASTM A105 & A182 · Jeddah Stock

Request a Quote — RTJ Flanges from Jeddah

ASME B16.5 · EN 10204 3.1 MTCs · SAEP-347 Compatible · ISO 9001:2015 ·

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In Summary

Gulf Union Ozone Trading Co. supplies RTJ Flanges to industrial customers across Saudi Arabia with delivery from our Jeddah warehouse — all products ship with original Mill Test Certificates and Certificates of Conformance.

In Summary

RTJ Flanges from Gulf Union Ozone serves Saudi Aramco SAEP-347 projects, SABIC, SADARA, SEC utilities, NEOM mega-projects, and industrial facilities across the Kingdom — our inventory covers the most common material grades and pressure ratings.

In Summary

Gulf Union Ozone stocks a wide range of RTJ Flanges including various grades, sizes, and pressure classes — contact us on WhatsApp for immediate availability confirmation and a quotation with full MTC documentation.

In Summary

For urgent RTJ Flanges procurement in Saudi Arabia, WhatsApp +966 55 098 8062 — our procurement team confirms stock availability within the hour and provides competitive quotations with full compliance documentation for Aramco, SABIC, SEC, and government projects.